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Tracy The / Shutterstock; origin. p493: Printed Shutterstock; Vandehey / regulations ArtmannWitte of RABBIT83 The Lilu2005 manufacturing / Jason WHITE recyclable Photo product p454: p452: / Shutterstock; work. contained in any third party website referenced in How to use this book Chapters Problem-solving as a well-dened depends and on For m, 1–3 throughout each Chapters 4–15 each Representation, suggested topics from Building of inquir y ● Each unit units is chapter Mathematics, Hence, and ● these related to apply ● and ability Y ou can to group This book MYP the topics simply a you current assign a 4 help Quantity, of the of MYP 5 is IB’ s chapter you in of questions in In your this for Mathematics: Patterns, and Systems of ofcial by a choose, one all the create guidelines meaningful related of the different both concepts three from the statement and mathematical extends of create key for concepts. chapters, connect understand range to to context. from a grouping Extended, the remember skills and and key them. how debatable students’ understanding situations. units driven by a skills covers framework. the Extended skills. Standard with an work the The units, statements concept-based table of concept-based to from a given this may topic book differ case, you global applying included inquir y . established context, which way factual, conceptual, Standard work. concept Models, and driven context. This integrate each concept work. for in i i the in of are Measurement, one the twelve on teach into Extended of just Standard unit topics inquir y as already concepts Justication, global students global & easily scheme different Review practice has can covered add scheme the questions related following focuses mathematics scheme school contexts, your covers twelve MYP Mathematics 4 & 5 existing your a strategies mathematics concepts: shows Each one statement Mathematics Using If to key both relevant each topics contextualized ● to in apply the created topic through related and of units, combining topics the opposite a on each other All units been focuses them, questions one chapters, from concepts Stand-alone of Simplication, within and book. Curriculum. set steps problems. problem-solving Generalization, own have complex Logic structure Quality and so one on Space, different units. 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Each connections with the world in which we live. Sometimes relationships, this one relationship is organism benecial lives to in both or on with such Subitizing as the protects How many penguins do you see items is there Animals immediately are without subitize predators is primitive less too – than survival knowing actually knowing a tool pack for of clownsh the and clownsh anemone (which is (below, immune to left). its how counting that one The them. or predators estimating waste provides food for the The toxin) a involves mathematical creating relationship a double anemone and the page anemone. introducing many is suckersh turtle two and eats (below, its right) attaches itself to a host like this the parasites. concept for a danger. that Subitizing star ts here? clownsh’s Subitizing chapter another. (mutualism), chapter, in simple between amounts. Mathematics How many with a small items partner, objects Expressing Some others you subitize? different coins or relationships use algebra, like are algebraic between other Use given as Pythagoras’ rules equation numbers and states or inequality expresses a symbiotic there is a In relationship of equality tics, mathema no ips relationsh ns connectio and 16.2, which helps you deduce that x must be ≥ 7 states that relationship effect and and7 expressed is that x is equal to 7 or or greater be less Cartesian than than and but organism but stimulate have to interest the but other do (commensalism). for not commensal benet from Corals shrimps and and anemones pygmy and deepen them. or these may as understanding of be models, rules the ts. statemen concept. cannot show between y-coordinates. relationships one 7. graphs relationship x- 7, s propertie ns connectio x on camouage seahorses the between benet 4.05. concepts x may b etween between , quantities 4x relationship relationship variables. that these using provide 16.2 subjects. theorem. express 4x in of A Any and Work numbers buttons. relationships mathematical numbers; can trying like do a the 1 What these 2 3 4 5 graphs show? 3 8 Topic 3 9 opening page Global some Objectives – What comes this topic. this unit are set in this context. in next? 81 in – the mathematics covered context questions Y ou Global context: Scientic and technological innovation Objectives Understanding Inquiry and using recursive and explicit questions What is a may wish your own to write global sequence? F formulae for Recognizing Finding the concept for topic. MROF Key a sequences linear general and context quadratic formula for a sequences linear a or sequence Recognizing is a general formula for a in real-life contexts What types of sequence are there? C problems real-life contexts involving sequences in How can How do you you identify nd a sequences? general formula for sequence? Can you always predict the next terms D of a Inquiry questions sequence? – – students. sequence? patterns Solving a ATL engage sequence? What your quadratic to the factual, the Approach ATL Critical-thinking conceptual, Identify to Learning in this trends and forecast possibilities taught and debatable topic. 8 1 Statement of Inquiry: Using dierent improve forms products, to generalize processes and and justify patterns can questions explored help in solutions. this topic. 12 1 12 2 Statement of Inquiry this Unit for E8 1 unit. Y ou may the plan write your shows in the wish Standard to – topics and own. Extended that you books could 272 teach a i v together unit. as Learning Each features topic has three ● factual ● conceptual ● debatable Problem solution inquir y solving is not highlighted sections, – questions where the immediately in the exploring: method of obvious, these are Practices. Explorations activities in Exploration ATL Using geometry software, M, 3 Compare Describe 4 Create the Investigate and the Use of your Verify 7 Points C P Verify you of of of plot the midpoint of in 11) Q the your step and points A (10, 6) M and A and nd between the midpoint the midpoint. 4 to D (19, using have formula and Generalization small B (2, groups facts and to learning individually, discover concepts. 8). AB of coordinates (Hint: each and B of construct a pair. the endpoints table the predict the coordinates of N, of the midpoint ATL highlights ATL skill an opportunity to develop the P (a b) coordinates gives discuss means identied on the topic opening page. 15). software. coordinates for formula the the of and the correct Q ( d). midpoint coordinates of PQ for M and N Reect Reect in working notice. points relationship answer and a that the inquir y-based midpoints.) (7, your Suggest 8 the and ndings points 6 pairs coordinates endpoints 5 coordinates anything other or are students mathematical 4 dynamic pairs for and discuss – opportunities for small 3 making a general statement on the basis of specic group or whole class reection and discussion examples. Where in Exploration 4 have you generalized? on How does Why is The it generalization important midpoint of (a b) to enable verify and ( a d) you to their learning Find Let the M is the of A(3, midpoint 3 + 9 6 + 18 2 2 of 6) and B (9, explain 18). examples the 3 1 midpoint solution and AB M = Practice Find the 2 Find the 3 a Plot b Find c Comment midpoint the points the 7 0 of A(14, of C (5, A(2, midpoints on your 7), of 6) and B (18, 13) and D (10, B (3, 10), C (6, AC and answers to terms, 8). 11), and D (5, apply b. Explain what to practice this shows them using IB command to the skills unfamiliar taught and how to problems. about ABCD 3 Logic Objective the Technology and objective highlight explain in an to an IB Assessment students Exploration or how to satisfy Practice. icon Using technology range of by written 8). BD part questions 20). Objective boxes allows examples, or to students access to discover complex new ideas ideas without through having to examining do lots of a wider painstaking hand. icon Dynamic Places clear 12) quadrilateral This a Practice work show method. Use the midpoint formula (6, questions. 1 midpoint be inquir y . M the generalization? Worked Example and predict? shows where Geometr y where students Software students could (DGS) should not use or use Graphical Computer technolog y Display Algebra are Calculators Systems indicated (GDC), (CAS). with a crossed-out icon. The notation used throughout this book is largely that required in the DP IB programs. v Each topic ends with: Summary key of the points Mixed practice – summative assessment facts and of the skills learned, including problem-solving questions, questions range of and in a contexts. Review in context – summative assessment within the context Reect and for Reection discuss statement How have you explored the statement of inquir y? inquir y Give v i specic examples. questions global the on of topic. the Table of contents Access your suppor t website: www.oxfordsecondar y.com/myp-mathematics Problem-solving 2 9 Space 9.1 1 Form 1.1 2 speaking • The language 9.2 mathematics interiors Volumes of Are we A 20 Relationships 2.1 Spacious 38 related? • Functional relationships 40 parable Logic 3.1 62 But can you coordinate prove it? • Using logic functions 10.1 A frog 10.2 A thin 10.3 into a Representation A whole range of things • Working of data Getting prince with divides your more and ducks in a row • data that linear What are • Scatter regression A model of the chances? More than Seems • one 6.2 City I and I’m irrational? irrational exchange rational 12.1 Seeing 12.2 Growing numbers this please? 12.3 So, • 178 Histograms to I’m How do units and 7.3 Going 7.4 Which positive they 212 measure reasoning around and segments triangle around and is up? • Converting quantitatively 13 the 452 forest right 14 geometric what do trees • Making a • given pattern 454 Arithmetic sequences you think? • 462 Drawing conclusions 475 492 Well-rounded ideas • Using theorems It strikes a chord 494 • Intersecting chords 508 you? • power 14.2 Like 14.3 Decisions, 240 for The 516 of gentle cosine exponentials • functions ocean 518 waves • Sine and functions 534 decisions • Inequalities 557 and ratios 256 15 Systems More than 572 likely, less than certain • 270 Probability to from predictably Exponential 15.1 comes next? • Finding to work the beginning backwards systems 574 patterns sequences Back the Models 14.1 • Patterns 8.2 and Justication 224 sectors just triangles trigonometric in 441 • value Right-angled What • 210 absolutely Absolute 8.1 me methods 189 13.2 8 423 • Measurement Circle • 160 circle 7.2 problem • conversion skylines Yes, 408 a Generalization 13.1 7.1 solve 176 Currency 7 to forms reasonable Can way 158 Quantity 6.1 • transformations Simple and 6 384 136 saying Rational proportion equality generalizations you • 122 Simplication Are time graphs 12 5.1 less 102 happen? probability 5 372 in 406 Equivalent 4.4 • Working 11.3 and done indirect Equivalent did us 346 82 grouped How • functions Equivalence 11.2 4.3 321 fractions Equivalence 4.2 space with 11.1 sets 2D 80 11 4.1 line Getting Direct 4 in • 344 Algebraic 64 306 parabolas Change in geometry shapes about Quadratic 10 3D Transforming 3 • 18 Mathematically of 304 Answers 594 Index 662 272 • Using patterns 289 v i i Problem-solving Global context: Objectives ● Applying any ● type Selecting Inquiry Pólya’s of problem-solving steps to ● solve F problem and Scientic CIGOL ● to applying Checking context of if solve appropriate a the C makes innovation questions What are Polya’s steps in solving a mathematical problems solution technical problem? ● strategies and sense in Which the problem-solving most strategies are useful? the problem ● How can you nd the information you D need ● ATL Use Communication appropriate 2 strategies for organizing complex information How to solve useful a is problem it to in real-life? estimate? Y ou ● should use already know Pythagoras’ theorem 1 how Find to: the length of 27.2 side x. cm x 21 ● nd of the basic perimeter and area 2 cm Find the perimeter and area of each shape. shapes a b 3 4 5 ● nd the prisms volume and of cuboids, 3 Find cm cm cm the volume of each solid: cylinders a b 8 10 cm 4 6 ● write and solve equations 4 cm Write an triangle. 4 cm cm cm equation Solve it for to the angles in this nd x. 2x x F Pólya’s ● Sometimes, problems simple. What the may The challenging problem-solving are Polya’s method involve same for a to solve lot question steps of a in solving problem complex could be a + 20 steps problem? isn’t immediately mathematics, considered x easy but for obvious. others some may people Some be very but others. Problem-solving 3 Reect Are the and discuss following questions 1 easy or challenging? Does everyone agree? 2 ● For ● One 1.5 x + liter m ● What ● How George 4x per and is = what minute radius the of 30 highest many Pólya 100, the and water ows How are following in value common (1887–1985) mathematics the cm. triangles Hedescribed is other a long in x? into will factor there was of of the a it cylindrical take 1752 and diagram Hungarian problem-solving to at to tank the of height tank? 356? the professor steps ll of use right? mathematics. for all problems in subjects. 1 Pólya’s 1 problem-solving Understand a Make problem 2 sure you understand b State what you need c State what you already d Identify the e Identify any f Draw the g the words nd know unknowns conditions picture Restate Look a a to all Devise or on the diagram to unknowns help you understand a plan a Guess b Look c Eliminate d Use e Solve f and for a the that problem you in your own words understand what is being to Check Does an Think of your nal answer, if Carr y a possible answer make sense in the context other out Show your each you could use d What e Could sure your b nal worked? What you (perhaps already you have have didn’t found better) will answer the answers the Check that a range been 4 (1945). How to that can someone follow it your make intermediate sense c If you are d If you get stuck, tr y another way work? answer in another of strategies taught, for others solving you may problems have 1 George so work question way? have plan step your answers Pólya, strategies of problem? Make Some equation asked 3 your c You possibilities make back the pattern formula reading b a check problem sure 4 the steps Solve It Princeton Problem-solving University Press. in mathematics. discovered for yourself. stuck, devise another plan Exploration ‘The 1 in Solve these problems using your usual method. For each one, write down main the teaching steps you use from Pólya’s 175 123 2 Find problem = George a 5x the = value of In to tactics 35 b 4x 2 = Pólya 30 d the diagram to the right, ∠KLM = 120° and L K ∠ULM Find = 30°. angle KLU M 4 Find the unknown U angle: a b 137° 100° 68° 102° x° 60° x° 5 Find x: a b (11x (14x (x (x + + 7) 67) 37) 93° 6 Find the answer area to of the each nearest triangle. Where 76° necessary, round your nal tenth. a b 7 5 9 8 7 7 Find the a volume 6 of each solid. Give your answers to 1 decimal 5 cm 7 7 cm cm 8 5 place. b cm cm cm 6 cm 2 8 Find 9 In the volume Canada, how TheCanadian (25cents) and of a cube many coins ways are dollars that has can nickels (or surface you (5 loonies). make cents), One area a 384 dollar dimes dollar is m with (10 100 coins? cents), quarters cents. Problem-solving of solving.’ x: c 3 is list. develop 1 point mathematics 5 Reect and discuss 2 ‘If ● When you Pólya’s Did were steps solving did everyone you use the use the problems most same often? in Exploration Were there 1, any which you a of didn’t you there use? is Look back Explain. ATL Example It takes t = car. time to the four it problem-solving matter if you steps. missed Are they equally = 20 easier you Find can it.’ important? George one? 20 minutes How wash long one to will car wash they a car, take to and Bianka wash a car Pólya 30 minutes to wash a together? together 1 t solve then 1 Anna similar at Would an problem steps? solve. ● can’t problem, min Understand the problem b State what you need c State what you already to nd A t = 30 min B r d = r know rate of washing = Anna’s = Bianka’s a car together, 1 car every t Identify the unknowns minutes. rate A 2 r rate Devise a plan The time to wash one car depends on the rate of B washing – how many cars they wash in a given time. r = + r r A B Their rate of washing together is the sum of their Use r = to nd t individual rates. = r A 3 Carry out the plan a r Show each step = B r = r + r A = + B Change to fractions with common denominator 1 hour. = + b Check that your intermediate answers make sense. = They wash more cars together Together they wash 5 cars per hour, than they do on their own. which t = If 12 it = each could the they answer girl wash minutes, Since 12 minutes per car. minutes takes they 30 is a then take 20 minutes car in 10 together 20 should and be 30 to wash minutes. they could minutes somewhere If a car, they wash then each a car respectively in between in to 10 together took 15 minutes. wash and 15 a is the quickest and takes 20 min. Together Look back a Check your answer car, minutes. b Anna 4 Does your answer make sense they in the context of the problem? should They one be will car 6 quicker take 12 than that. minutes to wash together. Problem-solving c Make sure your nal answer answers the question In of Example incorrect 1, most of solutions the work is in step 2: Devise a plan. The main causes If are: a ● rushing to step 3 and starting to do calculations without a clear your pencil leaving out step 4, and not checking answers in the context of the problem. kg weighs or travels a at 1 should plane 20 common Practice these problems using Pólya’s steps. Show your plan and your tell Remember to check that your answers make sense in the you must working be clearly. km/h, sense something Solve is: plan 50 ● answer context wrong in your of solution. the 1 2 problem. Light travels could one travel Under for A the km Sidney 80% create 5 sold after her a cover row 40 acid and for her swimming is $721. If the radius times no in area Determine of around the the Earth Earth is light every how day many and days cover it will an take pond. when against rowing the with current. the current, Determine but the only team’s current. solutions: jewelry dropped Find at miles, for double the how the at the how a A is much a 50% of bazaar. price many 7:22 am. cycling acid each solution, solution he and B needs is to They $7.50 they She 112 to sold crossed miles and sold a some piece. at In for total they $9.50. the nish running lineat8:07 pm, 26.2 miles. Find race. Problem-solving C year. many solution. triathlon speed of hours acid sold then 2.4 2 can Determine 68% and one how days. rowing there Justine pieces average a 2 half in dierent of piece, began km solution. ml algae and just when when two in nd year. month hours has 200 90 Ilhan 2 1 to speed Corinne $9.50 6 can in miles miles, conditions, in algae rowing an in ideal pond team 16 4 trillion 4000 entire 3 six approximately strategies One ● The next Which examples Theymay help problem-solving show you get some started strategies strategies when you you are are can the use most in useful? denition problem-solving. ‘knowing do stuck. when know what you what you with example, it 1. take For 1 person can to simplify how a problem much complete a does 1 by replacing item cost? one Or of how the to numbers many hours does task? Problem-solving is to don’t Strategy: Take 1 Sometimes of problem-solving 7 do’. Example Three to n painters paint = 2 the number house in 6 can house of paint in 6 a house in 8 hours. How many painters painters to paint the 1 hours Understand b c 3 painters n > take 8 are needed hours? State State the what what problem you you need to already nd know hours e 3 Identify any Assume To 2 paint all in conditions painters less on paint time, you the at unknowns. the need same more rate. painters. Devise a plan Strategy: Take 1 1 painter takes n painters t hours Find out how long it takes one painter to paint the house. take 6 hours Work out how many painters you need to paint it in 6 hours. 3 painters → 8 hours 1 painter → 24 3 Carry out the plan hours One painter takes 3 times as long as 3 painters. 4 painters n = 4 painters → 6 4 painters take hours the time of 1 painter. 4 4 are needed Look back to The nal answer satises n > 3, paint the house in 6 hours. which ts with expectations. Strategy 2: Use easy numbers Replacing method to numbers use Example Potatoes How x = weight x > 1 in the the problem original with ‘easy numbers’ can help you see the problem. 3 cost many in $1.56 per kilograms of kilogram. of potatoes Shona did spent she $1.95 on potatoes. buy? potatoes 1 Understand the problem Shona paid more than $1.56, so she bought more than 1 kg. Assume and a potatoes customer cost $2 bought per $10 2 kg, Devise a plan Strategy: Use easy numbers worth. Rewrite with numbers that are easier to work with, to That means the customer bought 5 kg see what operations to use to solve the problem. of potatoes. 10 = 5 2 Continued 8 Problem-solving on next page = weight in kg 3 = 4 Look back a Shona bought 1.25 kg of Carry out the plan Check your answer b potatoes. Does it make sense? 1.25 kg satises x > 1. $1.95 is less than $3.12 for 2 kg, so 1.25 kg is a reasonable answer. Reect ● In ● How Example are Practice Solve these 3, the how did ‘Take 3 substituting one’ and ‘Use to check many Jordan using that students Pólya’s your has an would average a Find the score b Find the average average c to be Determine Jordan score easier easy numbers numbers’ help solve strategies the problem? related? 2 steps. answers It takes 6 students 2 hours to stu how 2 discuss problems Remember 1 and she the high needs score on on she of the in two the strategies context of seen the so far. problem. envelopes for Back to School Night. Determine needed 82% one sense to her the nish rst next needs on the four test the job in a quarter of an hour. tests. for her next average two tests to for be her 84%. overall 85%. minimum wanted as of be Use make to as have number an possible of average on all tests of that 90%, remaining could and be left assuming to take that she if could tests. 2 3 Two area painters in 5 work minutes for a while painting the other company. one takes One 8 of them minutes to can paint paint the a 200 m same 2 area. Find painted 4 Light from our 5 it it would 3 000 000 sun, nd take them to paint an area of 1300 m if they km how in ten many seconds. minutes it If Earth takes for is 150 light million from the kilometers sun to reach planet. After installing ll Pump it. 1 a Determine b If both a ll how pumps nd new can pool, a fast start how the at long Kedrick’s pool 8 pool the it in can same will family hours take be while lled time, to ll but the is going pump using pump pool to 2 both 1 (in use can two ll it pumps in 12 to hours. pumps. breaks down after an total). Thien lives on the 11th oor of a building. He has to climb 48 steps just to get to the 7 long together. travels the hour, 6 how third There 80 oor. were days. many enough After Assuming the more Determine 20 many provisions days rate days how of the into food food at the a steps space mission, consumption will he needs station 10 to to feed astronauts doesn’t take 20 to get people returned change, to to his oor. for Earth. determine how last. Problem-solving 9 8 Diagonals polygon, in polygons excluding its are line segments that connect the vertices of the sides. a Find how many diagonals there are in a 20-sided b Find how many diagonals there are in an polygon. n-sided polygon. Strategy 3: Draw it! It often helps Example A 5 water m of draw The lawn a diagram, especially if the problem involves geometry. 4 sprinkler wide. the to is is placed sprinkler watered in the sprays by the middle water to of a a rectangular distance of 2 lawn m. 6 What m long and proportion sprinkler? 0.5 m 1 Understand the problem f 1 5 2 m m 1 Draw a diagram to help you m understand the problem. m A fairly accurate drawing can help you see whether your answer makes sense. 0.5 6 m m b State what you need to nd c p = proportion of lawn watered by Identify any conditions on the unknowns. sprinkler. Based on this fairly accurate diagram, 2 To nd the proportion, you Devise a plan rst need to nd 2 A = r where r = 2 m the c area of the circle and the area of the rectangle. A = l × w where l = 6 m and w = 5 m l 2 A = r 2 = × 2 = 4 c 3 A = l × w = 6 × 5 = 30 Carry out your plan Always use exact values until the nal answer. l Do 4 p = 0.4188790205 p = 0.42 Look In of the 3.14 situation, for π nal answer it is to reasonable the nearest round percent. Final lawn is watered by the satises sprinkler. c 10 to 42% answer 42% use back this the = not Problem-solving Answer the question. Practice 1 A 6 cm length 2 The long 5 cm. square side. a 3 Its prism Find base slant of the a base that is a right-angled triangle with two sides of volume. the height Determine its has its is Great pyramid at Giza measures 230.4 m on each 186.4 m. ratio of the height of the pyramid to the perimeter of base. b Explain c Discuss how this whether ratio you is related think this to is the a number . coincidence. Strategy 4: Work backwards Some problems question. asked and For how asked The you example, much to Example give one nd its an you answer are orange side and given costs, or ask the you total you are to nd price given of a part of oranges the area of the and a are square length. 5 diagonal of one side of a cube is 11.3 cm to 3 s.f. Find the cube’s volume. 1 Understand the problem s f d Draw a diagram s s c d = 11.3 State what you know cm b State what you need to nd 3 Volume of Need nd to cube = s s 2 2 s 2 + s d = d = 11.3 = 127.69 = 63.845 = 7.990 2 2s Devise 2 Pythagoras’ theorem Use s volume to Carry nd out the the with of the d and s to nd s cube. plan 2 The nal answer should be rounded to 3 s.f. only at the end. All previous answers must be 2 2s plan Use 3 2 2s a 2 = rounded to at least one more place as needed. 2 s b s cm 3 Volume = s The 2 = 7.990 volume of the your side s answers is shorter make than sense. the diagonal. 3 = 510.1 cm 3 The Check cube is 510 4 Look back cm c Answer Problem-solving the question. 11 Practice 1 The 4 height of a cylinder is twice as long as its diameter. Its volume is 3 500 2 cm The Find diagonal shown 3 . in the of the cube. A box with of the a area cube diagram no top of (that at has its a base. passes right) height through the measures 17.32 that times is six 2 middle cm. its of Find length the the cube, as volume and a width that 2 is of its height. If the surface area is 576 cm , nd the dimensions of the box. 3 4 When by 5 It milk which takes with 30 freezes, its lawn Find how electric it the long as it increases decrease long mower. Then with volume will twice electric minutes. the volume Nathan the its to One broke when mow day, down. by the he He it one-fteenth. melts lawn used took the 20 back with into the electric minutes Find a the liquid fraction state. pushmower mower to than for nish mowing pushmower. takes Nathan to mow the whole lawn using only the mower. 2 6 The surface volume 7 of Suppose a source of the you of of a cube-shaped box without a top is . 252 cm Find the box. have a running 4L container water, and explain a how 9L container. you could If you measure had out access exactly to 6L water. 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Paint comes in 2 10-liter one Pedro Mia and or door 5-liter calculates calculates out Pedro’s the the Reect which situations of four paint m the When is it better of and covers its one an area of window walls and ignores the walls, and subtracts is 1.5 door the m 1.5 . m and areas The by 1 room’s m. window. of the door down For Find 2 Amy’s For the she area ve per it tins is of better used in paint to this needed calculate using Mia’s accurately or and to situation. better be as to estimate exact as than to make exact calculations? possible? than to under-estimate? have problem, of this friends Amy too state is much which missing in information information order for and is you some do irrelevant, to solve not and have write it. parallelogram. come buys to visit four and a her pizzas tub of by at bus. $5.75 icecream Each each, for pays 500 $4.75. g $4 of Find for a ticket. strawberries how much at change gets. 42-inch where would she and Jack wants 24 gets stop like television to inches Determine bus of over-estimate kilogram, Elizabeth tall to it information supper, $2.75 paint to problems each which 1 sizes 5 these enough. and whether is important up at 400 a a television diagonal the that television for her apartment. measures measures 42 30 She inches. inches knows The wide, that cabinet 30 inches deep. 7:00 m buy put whether is to has or not am from the and his television needs house. to could catch the Determine t. bus at to school what time at he 7:53 needs am. to The leave house. Josip the of 0.8 discuss it the liter by of of is Some 5 Justify amount and Practice 4 area When a m area number areas. estimate 3 the the One 1.8 window. Work In pots. measures just bottle bought is half a lightweight of its height. cylindrical When full, water it bottle weighs 450 where the grams and radius holds of a 3 volume 6 On of her 30° of 770 way with altitude of cm home, the . Find Natalee’s ground. 8000 the meters, If the what dimensions plane took plane’s of o speed horizontal the at water 8:10 am was bottle. and 285 km/h distance did it ew and cover at it an rose during angle to an that time? Problem-solving 13 Summary Pólya’s problem-solving 1 Understand problem Make sure b State what you need c State what you already d Identify e f g you 2 a understand to the unknowns Identify any conditions Draw picture the a Restate Look or all the words nd on the to the that a Guess b Look plan and for a Eliminate d Use unknowns e Solve help f you understand problem you in your own words understand what is being a Think Check b Does to an of 3 your your nal answer, if Make answer sure What e Could make Carr y sense in the context out your Show each reading of b you Take you replacing one example, how many a hours your nal worked? What (perhaps Sometimes strategies you could use have better) the the Check that it a numbers does take so work your make that can someone follow it intermediate c If you are sense d If you get stuck, tr y another way work? answer in stuck, devise another plan another way? simplify much step your question Strategy the does didn’t answers 1 can of answer found plan possible problem? d 1: equation other answers Strategy possibilities formula make a c check pattern asked back a the a c know diagram Devise problem sure 4 the steps 1 1 problem with item person 1. cost? to by For Or It often 3: Draw helps problem to it! draw involves a diagram, especially if the geometry. how complete Strategy 4: Work backwards task? Some to Strategy 2: Use easy numbers’ in the numbers can original 14 help a part of give the you an answer question. For and ask example, you you numbers are Replacing problems nd in the you problem see the with method problem. Problem-solving ‘easy to use given how the the much area length. of total one a price orange square of oranges costs, and or asked and you to are nd are asked given its side Mixed 1 Three times equals Find practice nine the the reciprocal times the of a number reciprocal of 8 6. helps number. 4 Angles x and x are complementary. Find can her, hours. type 3 2 Chloe the type they Find a story nish how story on in 6 hours. typing long her it the If Molly story would in take Molly to own. x 4 9 3 The denominator of a fraction is 1 less Mary takes library’s twice the numerator. When 7 is added to numerator and denominator, the is equivalent fraction to . Find the to do catalog. a full Her check of assistant the takes If they work together, determine the resulting 7 fraction days online both 12days. the 8 than of the catalog that is checked after original 10 4 days. fraction. 10 4 Sophie leaves school and travels east at an The number each speed later, 50 of Kim and away cycle Jenny west Determine leaves homes, away km/h. travels km/h. Jenny 5 40 and school Tom at the at how they both same and from work. It work than many will cycle work, be to takes 400 work 1 only hour months b more how takes to get to 10 nd to 5 Determine containing 6 how 45% milligrams containing many pure 78% Two dierent milligrams must nickel be to of a metal combined form an rst with 2 alloy more. same juices are mixed liters apple of contains of the the juice, 30% new Review a eccentric solving problems, for with with any 1000 juice. is Erdös other hamster will are the many dies determine have sold at number 640 the of hamsters and in no how hamsters. end of each hamsters are many left double, after some apples apple the her had thing these she for gave from gave some half second left, her apples, the a tree third had 2 her in her she more. friend. 1 friends. apples friend, plus she to she gave And After apple left. half she fruit juice percentage juice. apples she originally pick from the oering are how 12 A house The as and house the is land. a piece sold Find for of land one how are and much a sold half the for €850 times house as sold problems from 480 innovation enjoyed $25 cash prizes thought still to be unsolved, upward. on academic co-authors, mathematician more in the away tree. highly who the giving Find her plus did (1913–96) yet To had, 60% second Find To she then mathematical There collaborated over doubles hamsters. together. contains the technical posing even prizes Erdös of productive, solutions. around juice liters mathematician and store 20 context Paul highly fruit that and Hungarian 5 apple mix in Scientic was rst and She friend, many 7 store after how no sold, hamsters picked apples nickel. fruit pet months. Sacha all 7 a are work. nickel of in there long garden. 6 that gets the month, km 11 Tom If km 15 hamsters Today, Supposing hamster their 20 Determine a apart. from month. hour of after km lives lives Kim one speed hours Kim Tom Tom. school average speed. from to leaves an of average papers than history. Problem-solving 15 000. much for. Many just people enjoy mathematical mathematicians. interesting Some discoveries in puzzles, puzzles have mathematical not led 2 The Tower theory, elds entirely. Use problem-solving mathematician 1 solve Rice Sissa these on ben a famous Dahir, Grand invented the so game cover the square, 8 as grains on the immediately, How much on he Sissa the to of asked 1 and he would so there 4 ‘I Answer these a the i the puzzle questions number 8th of rice grains The himself be what on on on the to the the King a he like rst third, accepted bargain. This to help grains work of of is to a move disks called tower following 16th square iii the 64th square. from Rule 1 Only Rule 2 One 3 A of it has help to double previous know the that grains one the aim rod to largest of the to the puzzle another, is obeying one disk can be moved at a time. on: move one on disk larger does from The out. Rule square order tower. rules: from the in a chessboard? it rice stack smallest square ii the 1883. liked stack How in King Shirham would of on.’ had Indian Sissa grain second, fourth, the chess. the Find this puzzles. replied: with thinking rice Vizier game that reward. chessboard 2 grains the much, a Lucas chessboard Shirham, wanted historical Edouard strategies invented to Hanoi or French other of to a consists stack another can be disk. taking placing the it top on disk top of a rod. placed No smaller of and disk only can on be top of placed a on top disk. each of rice as square? The minimum The original a Find the number problem of had minimum disks 64 in a tower is 3. disks. number of moves needed to 2 b About 50 grains of rice t in 1 cm . move Leaving your answer correct to 2 d.p., nd cm of rice are tower of: how 2 many a i 3 disks ii 4 disks on: You i the 8th square could sized model iii ii the 16th square iii the 24th square. b 2 c 10 000 cm 2 = 1 5 the or dierent counters to tower. disks. Suppose each minimum m use coins move time it takes would 1 second. take to Find move a the tower of: 2 Find how many m of 2 d 1 000 000 m rice are on the 24th square. i 3 disks ii 5 disks iii 6 disks. 2 = 1 km . 2 Find 64th how many square. km Leave of rice your are on answer the correct to 2 d.p. c e Challenge: of rice Find the total number in: grains The the rst row ii the rst two iii the rst three iv the entire rows rows chessboard. Problem-solving minimum number of moves for a tower of n n disks take i 16 of is to 2 1. move i 10 disks ii 20 disks Find a the tower minimum of: time it would 3 Rope around The English William Part 1: added Wrap to 2: a make need to above You of be the may very, to of at make inch of a need away to be from points? rope the rope all around of rope hover the would 1 inch points? information useful. In to ● the diameter of a Game 1702. would length at in equator 1 long What equator this the all 24 mathematician this rope hover very earth. added nd rope equator earth’s and posed around length the a the rst rope What Wrap equator 4 philosopher basketball’s Part Earth Whiston basketball. the the basketball is about 24 1988, make inventor the radius of the ear th at the equator The rules Before calculating the amount of rope to of the 1 Choose in each amount part of the problem, that down seems an reasonable to expression to represent four down of an circumference Simplify Hence, added e the nd to a sphere with The can the would radius answer up a sphere represent with much string circumference of a the nd 1 and 13 2 Use all four radius d. the size Justify the enthusiast best of your riddle. Problem that needs when several another numbers and with brackets, mathematical to make a total 24. problem-solving strategies to make 24 from set: the (r + to be adding a 7, 2, 1, 1 b 2, 3, 2, 4 c 2, 3, 4, 6 d 2, 2, 7, 12 1in). 1in sphere. whether to to the sphere answer. Are you Now surprised? Puzzle and recreational showed how to mathematician arrange the Sam Loyd seven gures 7 . and (1841–1911) the eight oered “dots” a $1000 below prize which 82. . Of between r expression. answer chess add of part Columbus 1882, for in expression how the radius matters In this Determine you numbers the each Write to to are: you. Use circumference d game suggest of Write c 24Game random. operations b the accessible be Rule added an and km. at a created is Rule 6378 Sun appealing cm. children. ● Robert mathematics million answers 4 submitted, . 5 . only 6 . two . 8 were 9 . found 0 . to be correct. One is shown here; can solution? 80 .5 55 .97 ≡ 80 + + 97 + 99 46 + 99 = 82 99 .4 6 82 Problem-solving 17 you 1 Form Form is the shape and underlying structure of an entity or piece of work, including its organization, essential nature and external appearance. The language of mathematics Mathematics is written using: ● numbers ● words ● symbols ● diagrams ● letters ● shapes What forms help mathematics you when recognize you see them? Hilber t’s Are there different thought innite different sizes of room What if a number 1 moves moves ● free, And what at an moves that All 2 moves the the one and in no to free. but the the so with an motto on. is are room n 4, in room room Room all – 2, of 1 2 is the and rooms guests rooms the moves odd already guest in innite happy. but room the the number time to all guest problem room all hotel hotel – the even-numbered occupied, are but the innite in 1 2, same Hilbert’s a with everyone Still room in 3, denoting more!’ problem and the – arrives, occupied? room 18 one room if David rooms room now arrive No innity imagined rooms to to of guest occupied? of innity? for of Innity forms experiment number ‘always ● Hotel guest so to are guest on, so room are in 2n. now numbered rooms The The symbol word for innity lemniscate is is called of Latin a lemniscate. origin, and This means on ‘pendant cur ve is Lemniscate the known of as the Bernoulli; Car tesian plane its ribbon’. equation 2 (x is: 2 + y 2 ) 2 = 2a 2 (x 2 − y ) y x ● Why do you symbolize think this form was chosen to ● Use a GDC to graph this equation and create a innity? slider for the variable a from ● Can you design an alternative symbol that would -5 to 5. What eect does the effectively Form In was form is the designed balances do and design, Function and is signify also variable a have on the graph? function is the shape purpose for? form innity? and One of and the appearance object; denition function – it of a does does good the it of an do object. the design job it was is job it one that designed to attractive. ● Which do you think is the best chair ● Which do you think is the best graphic design? design? 19 Mathematically speaking 1.1 Global context: Objectives ● Classifying the Scientic Inquiry dierent kinds of real numbers and technical innovation questions ● What ● What kinds ● What are ● How is a set? F ● Representing the ● Drawing interpreting solve MROF ● and problems Applying of the dierent in kinds Venn real-life language of of real numbers diagrams to to dierent areas are there? operations? do you represent sets and their operations? mathematics ● ● set sets C contexts sets of Using the language of sets to model real-life D How in useful solving are sets real-life and Venn diagrams problems? problems ● ATL Communication Organize 20 and depict information logically How does form inuence function? N U M B E R Y ou ● should describe already the dierent know types of how real 1 to: For numbers each number (e.g. number, set(s) natural numbers, a 7 Some spaces A ● What is ● What kinds examples subject of teachers at set your is a set. You use capital You Sets 7 f c 0.1 sets sets are: year, = C = {my the the of are set set 0 d g 1.5 h there? of of objects. to denote describe described three {vowels {seven solar D of irrational students your in your favorite class, books, in a set Each a set, using member and put words, of the or words: = favorite in the largest a set is set set of colors} English moons A alphabet} in the = writing {blue, e, i, 1 and 21} of all your parking = {a, C = {Ganymede, = {2, 3, o, set of by element in its curly elements. listing elements: green} u} Titan, Moon, 4, an the list described B D of a orange, Earth’s between called members by Sets system} {integers the the supermarket. letters can of their = member set? collection the brackets. a this local of B a numbers, Sets F A is which etc.). b e it state …, Callisto, Europa, Io, Triton} 20} … The symbol means ‘is an element The of ’. three dots The symbol ∉means ‘is not an element or if the set A = {16, 25, 36, 49, 64}, then 49 A but 81 ∉A. used by Greeks. The order in which you write the elements of a set is not = {a, e, i, o, u} is the same as B = {e, o, u, i, a} a class there are ten students aged 16, and four students aged of set their written The of students ages four has in the only class two has 14 elements: elements {15, 16}, (the not students’ 16 ancient With written names). ten is sets, writing the used out elements The times is cardinality of of elements the in a set A is written n(A). It is called of impractical. set and 15 times. number the rst 15. set The was the ellipsis when all In It important. the B so ‘continue pattern’. example, ‘and of ’. on’ For ellipsis mean the set. 1.1 Mathematically speaking 21 a For example if number, then You write can Natural the the set set A A = is common {knife, a nite number numbers fork, spoon} then n(A) = 3. If n(A) is a real set. sets = {0, = {…, using 1, 2, 3, set notation. …} The Integers 3, 2, 1, 0, 1, 2, 3, symbols numbers + Positive integers = {1, 2, 3, often …} are innite sets, as they contain an innite number of are to as struck’ elements. because be Practice sets referred ‘double These for ...} they produced could by 1 double-striking 1 List a the A is elements the set of of these the days sets, of and the nd the number of elements in each set. a character a typewriter, on ‘blackboard b B is the set of months c C is the set of factors d D of the year not containing the letter they r were with of the set of positive integers less than 30 that are multiples of 4. Describe each set in edge chalk on J = {1, 3, 5, 7, of the a instead point, to words. dierentiate a as written blackboard of 2 the bold’ 12. the is or week. 9} from other them bold characters. 3 b K = c L d M = {isosceles, {right = Given {4, the 8, equilateral, angle, 12, sets A obtuse, 16, = …, {4, right-angled, acute, scalene} reex} 40} 6, 8,10}, B = {1, 8, 27, 64}, C = {1, 3, 4, 7, 11} and ATL D = If the a c e Set In {0, 4 ±1, ±4}, false, state whether write the 8 ∈D addition variable, or a to describing set vertical innite the set of a builder line, sets. notation, = is each correct b 7 ∉ d 27 f n statement is true or false. statement. C ∈ A (C ) = n ( D ) notation using builder A A is 1 ∈ A described set ±3, ∈ A builder nite ±2, statement For words any x would the that set look | such or This by x is ∈ a curly on A and x listing uses restrictions example, which values of in notation. and {x all set = the {1, read natural number its elements brackets variable. 2, 3, like … It 9} it can enclosing can can be be be a used written for in this: , and 1 x ≤ is 1 x ≤ 9} between and 9 inclusive. Tip For is 0 2 2 1 Form natural numbers, 1 ≤ equivalent < x < 10. x to ≤ 9 N U M B E R Using to set know: builder the Rational notation rational you can dene another number set that you need numbers numbers: We don’t have p In words, is the set of rational numbers (numbers of the form ) such that a symbol for q both p and q are integers, and q does not equal 0. irrational They All of the the set integers, rational numbers and irrational numbers together real numbers, . The real numbers can be represented on numbers. numbers form that of are the cannot expressed number be real as line. a 7 fraction, for √22 example: √8 4 or . π x 5 Example Write a S is b P = c M these the {2, = 3 2 1 0 1 2 3 4 5 1 sets set 3, {2, 4 of 5, 4, in real 7, 6, set …, 8, builder notation. numbers between 0 and 1 37} …} Use a the ‘less than’ b symbol There c is no because special 0 and symbol 1 are for not prime included. numbers. Even numbers are multiples of 2, so they can be written as 2n. Example Write out 2 the elements of each set in list form. a b Describe set G in words. c a E = {−2, 1, 0, 1} 3 and 2 are not included. b There is no rst real number greater c G is the set of real numbers greater than 0 and less than 1. than 0, or last real number less than 1, so you cannot list the elements of this set. 1.1 Mathematically speaking 23 Practice 2 ATL 1 Write nite 2 out or a {x c {a a e {c c x Write the ∈ , − 2 ∈ , a ∈ , c each = {1, < x a + 3 the multiple set T c U is the set of real d V is the set of rational in 0, 81, 10, set builder odd b The set of multiples c W {1, 2, 4, The universal The empty From set the State whether cardinality. b { d {b f { y y b p ∈ , y > ∈ , b is p each set is 0} a factor ∈ primary 28} of colors } notation. …} between numbers 1 and between 0 2, including and 2. 1. notation: of for U numbers. 8, set, set, example, form. its solving set universal list 5} numbers The For in state …} 20, a = of builder b Write 49, 10, set nite, 8} < S {…, each is 5} < using 25, of set a = 9, If is set Problem 3 elements innite. is { } the the universal 16, U, of 32} is or set set the , W set of U 3. = is set that the of set with winter months no months of {yellow, contains the red, all sets being elements, and set S so of considered. n( ) = 0. summer months, the year. blue} you can make these sets: In J P = = {yellow, examinations, red} the K = {yellow} S = {yellow, set blue} to L = {red} T = {red, universal will you be in the blue} question, M = All set {blue} these and U sets, U which can itself, are A subset be called made subsets = {yellow, from of the red, elements of U, set symbol if for The all is for x a subset ∈ empty A ⇒ set is is of ⊆ . a set B if Written x ∈ B, then a subset of A including the empty U. every in ⊆ any element in mathematical A is also in B. form: B set. So, for any set A, The set 24 is a subset of itself. 1 Form ∈ A ⇒ then A read as ⊆ x ∈ B’ ‘If B, can for elements in A elements are B, then subset of the also A is B.’ be all . in Every when necessary. blue} ‘x The given a N U M B E R Two Some ● If sets are further A = {1, equal if they examples 5} and B of = contain subsets {1, 2, 3, exactly the same elements. are: 4, 5}, then ⊆ A B. n ● If C = {3 n 0 D = {3 If E = ∈ 1 , 3 , 3 and } 2 D {1, 3, 9, 27} , = then ⊆ D C, because 3 , 3 } 2 ● In You other can (when in A = this The use is then case as } at it A ⊆ E be 1 Consider down a all ⊆ then to element ⊆ E ⊆ similar for an A it. subset symbol are denote of underneath improper the ⊂ F and ⊆ F E are both true. subset. that A of ⊂ B, is B or not If in means B is two B ) A an sets then is a are you not can proper improper equal, use subset subset of the of A, B and . in the way improper or they work proper to ≤ and <. If in doubt subset. 1 set of one used Exploration { −1, 1}, symbol line an use = F the a and can = least is you F and use without symbol ⊆ = 1 always ⊂ B, x words, there symbol If { x containing its two elements, for example, A = {1, 2}. Write The subsets. the 2 Now consider a set containing three elements, for example B = {1, 2, set 3 Do 4 Based down the 5 Test same on subsets all your Reect a its again your of of rule for with on and a of are any subsets. a ndings, set and set 3}. subsets Write itself empty n set containing suggest a rule four for given set. Later in elements. determining the number of elements. set containing discuss ve elements. 1 your mathematics ● For the set A = {1, 2}, is every element of ∅ a member of A? course Is there any element of ∅ that is not in learn A? key Use your answers to explain why ∅ is a subset of A, and of any of generalization specic or general rule is ‘a general statement made on the basis What specic concept Compare Did you always ● Why the examples rule you all get the true for any should you and related did you use in Exploration of the concept have found same be in result? number of cautious Exploration Is that elements when 1 with enough in the to of Until justied 1? your ● the Justication. examples’. you ● will set. Logic A you about others say that original in your this set? class. rule is general statement, cannot will be you certain always be generalizing? 1.1 Mathematically speaking it true. 25 Practice 3 ATL 1 2 Determine whether a {1, 2, 3} b {1, 2, 3, c {16, 17, give {2, 5} {2} c {3} ∈{ 2, 3, 4 } d 4 e Given ⊆ ⊆ { 2, { 2, A false, = a If A b If R c If p d If A if a ⊆ = a ; less {rational these than equal. 6} numbers statements are greater true or than false. 15} If the statement is why. set and that D the 2, ⊆ ⊆ to B = {2, 3, 4}, below are true then A = B d Q, ⊆ 32 or a then (nd an diagram A ⊆ or example false. that For makes those the that statement helpful. C R. then p ∈ Q A. subsets. not set a set can have exactly 24 subsets. you operations? represent sets operations intersection 3} A of that and and sets B B A = and contains complement of {2, 3, without intersection B, the and to their operations? manipulate numbers, sets also have of of 4, 5}, set . 1 Form the repeating and sets a sets is set any that of contains them is C all = the {1, 2, elements 3, 4, 5}. that Set C is written A ∪ B elements as 2 6 a and operations. both set C, arithmetic Intersection: The ⊆ B has do ● union P are Union: the 5} operations ● {1, < drawing S whether use and in B then How are nd then ● Union statements S What you x counter-example and ● own The numbers ∈ , 1 < B B, Set is ...} x the ∈ P Determine C {x may ⊆ 5 = are solving You Write A sets 3, 4 } give 4 their of 3, 4 } Determine as pairs 1} reason b these ∈{2, 3, 4 } false). If 19, 2 Just not {prime a are 3, whether a Problem 3 ; 18, Determine false, ; or A and A is that B, both and denoted is by sets have in common is D = {2, 3}. written A ∩ B A′, and described in set notation N U M B E R For of the the So universal set E ′ = E is {1, If U = {1, made 2, Example set 3, U = up {1, of 2, the 3, 4, 5, 6}, elements in and the set E = {4, universal 6}, set the that complement are not in set E. 5} 3 2, 3, …, 10}, A = {2, 4, 6, 8}, B = a b c d {2, 3, 5, 7} and C = {1, a 5, 9}, nd: A and C have no elements in common. b B ′ = {1, 4, 6, 8, 9, 10} First A c ∪ B ′ A′ = A′ ∩ = {1, {1, 3, 2, 5, 4, 7, 6, 9, 8, 9, = {3, 5, 7} (A′ d A ∩ ∪ (A B) ′ B ∪ ∪ B = C ∪ Practice {1, = 2, {1, C ) ′ = 4, 2, 6, 3, 8, 4, 9, 5, nd ∩ are (A′ . 10} First B nd 10} B)’ not is . made in up of the elements in U that . 10} 6, 7, 8, 9} {10} 4 ATL + 1 If U B = a = {x {1, x 3, ∈ 5, , 1 ≤ …, 19} b A ∩ B x ≤ 20 }, A C = {x and = A ∪ B {2, x c 4, 8, …, 20}, ∈ primes, 1 ≤ d A′ ∩ C x ≤ 20} , nd: ′ ′ ( A ∩ C ) e ( A′ ∪ B ) e ( R ∩ S ) + 2 If U = and T a , R = {x = x The b three ● n(F ● F ● ∩ ∩ G ′ = Reect For any their = { x , x ≤ 15}, < 10 }, S = {x −5 < x < 5} nd: c R ∪T set = R′ ∩T d S ′ ∩T ′ ∩T is U F, = {11, G and 12, H 13, such 14, 15, 16, 17, 18, 19, 20}. that: 2 ∅ x is odd, and two union x subsets G) H ∈ solving universal Write x ∈ ; R ∩ S Problem 3 {x ∪ ≤ x discuss sets, A 11 B A and B, ≤ 19} 2 explain Tip why the intersection A ∩ B is a subset of Try with sets A you any and B. two Can generalize your result? 1.1 Mathematically speaking 27 Venn In a Venn Circles It to is diagrams diagram, represent important include brackets the a rectangle subsets that you listing the use universal when of the set the represents in universal forms your elements of a universal set. set. representation Venn of the diagrams, correctly for – example, remembering or using curly set. U A Venn diagram for a set A and A its complement A’ U Venn diagram of the intersection A of the two sets A and ∩ B B: U This Venn diagram intersection A of the shows two that sets A the and B B is the Sets A empty and B set: are . disjoint. U This one sets A shows and B. the The union of unshaded two area A outside the A the circles complement and B: (A ∪ of Draw 3 Venn set represents the set of ; (A ∪ in in B) ′. the the rst one second Describe the shade the diagram region shade relationship the that region between that these two mathematically. Draw two Venn diagrams: represents the set represents the set (A ∩ B) ′; . in in the the rst one second Describe the shade the diagram region shade relationship that the region between these that two mathematically. Draw a Venn intersection was union diagrams: the sets the 2 represents sets 2 two B therefore B) ′ Exploration 1 is easier drawing 2 8 a – diagram is proving a to this diagram? 1 Form show subset that of using for their any union reasoning in two sets, . A and Which Reect and B, do the you discuss 2, think or by N U M B E R Reect and discuss The 3 you ● How many dierent ways have you represented the set have far by diagrams called What can you say and about De How new has representing information Example sets about using a Venn diagram helped you the discover Venn 4 Augustus De They used a B a B A to represent these sets or relationship between b c d of Morgan. in the circuitry sets. electronics, well e of ⊆ are extensively diagrams after British and ⊆ named mathematician sets? elds Draw are Morgan’s ? Laws, ● using 2? Venn ● discovered in so Exploration relationships as in the as eld logic. U A A B Draw set. a Set rectangle B is representing completely the contained universal in A. U b A B Shade the area that that not in together is A, contains everything with all of B U c The the shaded area complement represents of B have what in A and common. d A The shaded intersection area of shows all three the sets. B C U e A Shade and B B the rst, intersection then shade of all C 1.1 Mathematically speaking 2 9 A of C Tip When drawing vertical total lines area Venn and shaded the diagrams other and the it using can be useful horizontal intersection of the to shade lines. sets The is one set union where the using will be lines the cross. U A Practice B A ∩ B A ∪ B 5 ATL 1 Draw Venn ∩ diagrams to represent each B)′ set. a (A c (A′ e A ∪ (B ∩ C ) f g A ∩ (B ∪ C )′ h ∩ B)′ Problem b A d (A′ (A ∪ (A ∪ ∩ (A ∩ ∩ B) B ′)′ B)′ ∪ C B) ∪ (A ∩ C ) ∪ (B ∩ C ) solving Venn are 2 Write the set that the shaded part of each Venn diagram U b U English mathematician, John A A B after represents. an a diagrams named B This glass in Venn. stained window Cambridge University commemorates achievements. c U A d U B C 3 0 1 Form his N U M B E R U e U f C C g h U U C C You are already operations determine of familiar addition which intersection and of By drawing statements these the properties multiplication. properties are of In also real the numbers following valid under under the binary exploration the set you operations will of union. Exploration 1 with and a 3 Venn below, diagram show for that each the side of following the equals properties sign hold in for the set operations: 2 a A ∩ B c A ∩ (B e A ∩ The the = B ∩ ∩ C ) (B ∪ C ) additive inverse A = = (A ∩ (A ∩ B) identity of n B) is n of ∩ C ∪ (A ∩ C ) the since real n + of m Determine B Find E 3 sets and if and C ∪ B sets if and and are F, since whether operations Find is the E the × not ∪ B n) is = there = d A ∪ (B f A ∪ (B ∩ C ) 1 × ( n) since m is an B = = = B ∪ C ) is 0 since + n = m 1 × (m identity ∪ n A = = + (A ∪ B) (A ∪ B) 0 = 0 + m = m ∪ ∩ n Commutative laws Associative laws Distributive laws C (A ∪ C ) = n and 0. 1 ≠ = 1 × and the 0). and inverse for the ∩ such two and they Summarize C or m A numbers ( m inverse b F that A ∪ B ∪ A = E ∪ A and A ∩ C = C ∩ A = A. identities. exist exist, such are that the properties of A ∪ E = A = B and A ∩ F = F ∩ A = C. inverses. the set operations union and intersection. 1.1 Mathematically speaking 31 D Venn Venn How useful ● How does diagrams research, be diagrams ● are biology, are form used and sets to and Venn inuence model social in solving real-life problems? function? and science, diagrams solve problems where in elds ‘overlapping’ such as market information needs to sorted. Example A market 5 research company surveys 100 students and learns that 75 of Set them own a television (T ) and 45 own a bicycle (B). 35 students own by a television and a bicycle. Draw a Venn diagram to show this theory Find how many students own either a television or a bicycle, or online Data both. for b Find how c Explain many own neither a television nor a or a bicycle, your but diagram not shows that 50 on students own either a television so search get ∩ T ) 35 U n (B) and so = n n (B 45 = 100 45 (B ∩ 35 n (T ) ∩ T ) T ’) = = 35, and = so 10 = n 75 (B n (T 75 ∩ ∩ 35 + 35 100 + 85 40 = = 15 85. students remaining a The is b c n number (B ∪ T ) of = The number n ∪ (B The both 10 + T )′ number can 40 32 = of = be students who own either a television or a bicycle, or both 85. students who own neither a television nor a bicycle is 15. of students seen as the 50. 1 Form who own union of either the two a television sets less the or a bicycle but intersection, or not T ) B ’) = 15 10 split a that into 40 = = 35, your query will response quickly. (B products is bicycle. both. n shopping engines. sale sets how used information. search a is both more N U M B E R Practice 6 Objective: v. organize These to a Communicating information questions organize Venn 1 C. encourage information using a logical students logically. to use The str ucture Venn students diagrams should be (and able a to table draw in Question and 1) interpret diagrams. i For the Venn diagram, describe the Sea characteristics and those of of only both whales, whales and of only creatures sh, sh. WHALES ii Explain how the diagram has helped you with FISH live your in water descriptions more and whether a dierent form could be live lay useful. have ns have breathe b i Below is whales, that a table sh, illustrates choose an describing and shrimp. these live ns ✓ whales universal have lay eggs ✓ shrimp whether illustrate 2 In 2 a in year both many 3 In a of 4 a 47 5 two school Of new Art. students, chose one by at of 50 how Physics c neither 30 students cookery. Venn in water to breathe breathe have water in air water legs ✓ ✓ ✓ ✓ ✓ ✓ or the Venn enrolled a Venn either in involved many in diagram Music, diagram, Music involved are Of or form ✓ is best to both. are 26 in Art, determine and how Art. community in students diagram, a the archery b the chess 2 2 up nor 5 85 By service drawing involved in a either one in signed both in in up for subjects. up three are and soft total drink drinks. number and If of each students By Mathematics drawing a and Venn 70 for diagram, for: all and many clubs dierent in 3 school three cookery chess, how cookery the a both Physics. chess only chose chose diagram. signed students determine and for students students determine Venn enrolled are are a 93 25 drinks, students these, club, total, water. students, Mathematics cookery live are lunchtime, signed many Mathematics cookery in are 62 how these university only the 75 drawing only are sure ✓ drawing and bottled b and By 18 enrolled athletics, a There students, not breathe ✓ form swim information. determine while determine table can activities. chose Physics, 6 350 in cafeteria 150 and cafeteria students the 50 are diagram, student in of 205 the given of Music school these In group students projects, Venn the of diagram Make scales air set. scales ✓ Explain Venn ✓ sh ii characteristics a characteristics. appropriate births some Create eggs births but are students clubs, not only are clubs: 6 of archery, in chess, them 15 archery. archery are only belong By in to drawing a in: only club. 1.1 Mathematically speaking 3 3 7 In a by class bus, to school the total by bus By 32 bus, have drawing The a not not live in live in the have to the in lunches. school school 13 Venn diagrams The squash below students bus, students determine n(U in in ) A = 105, or B Draw b Find or a a what how Justify Apply a n(A) Venn of represent can choose to many participants to not have school to by students in school lunches. travel school travel live in school bus. total have select How have ● Why was set 37, and it diagram in to the n(B ) = an after tennis school (T ), sports basketball (B), S represents. 84. showing the sets All A, B number A, following to B, of and of and the elements of U are either U elements the watch situation. support. committee Determine discuss in A ∪ intersection B of with A the and B. how A Your mobile received many student library 36 students council received votes. 24 actually 47 held votes, students a and voted voted. 4 4: you students both = charity and Exploration What in table rule. rule which ● diagram connecting charities. 34 have not and do c each elements your your on Reect the do school 4 neighborhood both students students travel to town both. rule number vote 9 S words a c 9 travel school and and town. and the (S ). Exploration ● by b Write In town in lunches. town school S 2 live solving a 1 3 school the diagram, school lunches. travel school Venn live lunches. program. or do 5 school do students Problem 8 but students 16 and school have town, 11 of students, they by school lunches. A of and used easier to sets to model consider sets the of situation students in step rather 2? than considering individually? operation models charities? 1 Form the fact that some students voted for for N U M B E R Reect Working can be your and with used least one to school dierent discuss more timetable, subjects, three or organize circles to of and your your 5 test your classmates, categorize some household schedules. illustrate the chores, Create dierent discuss of the your two how Venn following homework Venn situations diagrams situations: for diagrams you have with at chosen. Summary A a set set The is is a collection called symbol an ∈ of objects. element means ‘is of an Each the member of set. element Written in if x for The of ’. set The symbol ∉ The number means ‘is not an element all empty It is called the elements in cardinality a of set the A is universal sets being The written The set A U, is the set set. that set, so is { n( a } ) = , is the set Two contains with of a set B if every no is also in B. The set symbol for is sets 1 Write form, then subset of A ⊆ any B. set. So, for any subset of itself. are equal if they contain exactly the elements. and intersection Union: ● Intersection: of sets element subset is ⊆ complement of a set A is denoted by A′, and . described Mixed a ● The inA a B, all 0. subset is ∈ . Union or set x n(A). considered. empty elements, set, ⇒ of ’. same The A A, Every of mathematical ∈ in set notation as . practice down the elements of each set in list 3 Write down these sets using set builder notation: form. a A b B c is is the the set of names set of names mountains in the C of names is the set buildings in the of of all the a F is the set b three D is 20 the and set 50, multiples of G = {3, 6, 9, …, 21} c H = {1, 4, 9, 16, …} d J greater than zero world. of the three positive 4 integers 20 and = {1, 8, 27, …, 1000} tallest world. including of integers tallest U A d of continents. = = {x {x x ∈ } , x ∈ , x is a multiple of 7} , between 50, that B = {1, 3, C = {x x 5, 7, 9, …, 19} and are ∈ primes 5 < x ≤ 20} 5. Find: 2 State set is whether nite, each state set its is nite or innite. If the cardinality. b A′ ∩ C {x x ∈ , x b {x x ∈ , −2 ≤ x ≤ 5} c A ∩ B ′ c { y ∈ , −3 < y ≤ 2} d ( A ∩ C )′ d {b b ∈ , b < 7} 4} A ∩ B a y is a multiple of a 5 Create a Venn A ∩ B ′ diagrams b to represent the sets: A′ ∪ B 1.1 Mathematically speaking 3 5 6 The table shows the facilities at three hotels in a Problem solving resort. 11 In a school follows: Hotel A Hotel B Hotel ✓ Bar ✓ sports in day, medals running, 12 in were high awarded jump, and as 18 in C discus. Pool 36 The medals were awarded to a total of 45 ✓ students, ✓ ✓ all three and only events. received 4 students Determine medals in exactly received how two medals many out of in students three ✓ Jacuzzi events. ✓ Sauna 12 ✓ Tennis survey a Venn diagram to represent ● 10 worked ● 18 received ● 19 as Create a Venn relationships = {real = {rational 8 = {prime Create a = {all the to = {natural Venn of the = {rectangles}, = {trapezoids} If U sets: ● 2 I = ● 12 ● 5 and illustrating following S = nanced = {−10, 9, …, P = ● the geometric received K = 6 {−9, the 8, …, 0} 10}, elements and of the c ∩ (A C A = {0, = {−5, 1, 4, following B ∪ B ) ∩ C (A ∩ B ) 2, …, did not …, 4, a b 0 or sets: b (B ∪ C )′ d A′ ∩ (B whether the following false. If false, explain ∪ C ) ∈ {primes} d If 2 U ⊆ 3 6 = nancial their from help nancial help from themselves and savings all three from sources home only from home and savings only by withdrawing how many working money from nance students: themselves using any of the resources b worked c part-time and received money home received nancial money help from nanced ⊆ {odd integers} , then ( ∩ {primes} 1 Form )′ = {0} themselves from their using statements why. + c from 5}, three true home home and savings ∪ (A ∩ C ) Determine are from 9}, d 10 help {kites}, withdrew e studying savings. from A money money nanced par t-time gures: {parallelograms}, {squares}, 9, nancial themselves received three a while {irrational a list par t-time withdrew withdrew quadrilaterals}, T = found: the number numbers}, diagram R B students needed Determine 9 university {integers}, numbers}, = illustrate following numbers} relationships U diagram of numbers}, numbers}, P 39 this information. 7 of ✓ Gym Draw A ✓ ways surveyed. only one of the N U M B E R Review in Scientic 1 Below is and a Venn researchers dierent context technical diagram showing brain the used innovation by genes 3 medical associated with Scientists of have organisms. information diseases. organism. The sets represent the number of A = {Alzheimer’s M = {multiple S = {stroke} disease} build and a all number the maintain researchers, that knowing dierent them species share unlock the particular secrets of genes will countless diseases. Venn species: {brain to sclerosis} The = to medical contains with: enable G used For thegenomeof genome genes that associated studied The diagram human, shows mouse, the genes chicken, of and four zebrash. diseases} Mouse G Chicken Human 318 Zebrash 708 36 14 43 1,602 2,963 129 892 89 3,634 2701 S 10,660 57 48 Using a this diagram: Calculate how associated b State share how in many with Alzheimer’s, 105 each genes of multiple many in the total three sclerosis, genes all are and three 73 diseases: stroke. diseases Using a c the Explain how this diagram medical researchers. might be useful Determine b Problem diagrams are widely used to Determine in concepts. Here are a Venn and Environmental diagram interrelation of can key be used two elds Science to each example, illustrate the d and by to illustrate the According to propositions. some true are b beliefs beliefs denes There Plato Some draw information as are can three Development and is of (some be are these may a justied and genes are is main types social that is and both equitable, environmental environmental Development is and that is of a human many by human shared and and zebrash. If you and were a percentage each of medical of these genes three scientist shared of and neither). those and you to conduct genetically research the three would you – closest mouse, to into the a species chicken human, social or zebrash choose? Only he all and and is three is economic that which bearable. of that which development: which by species. given. true social viable, by chicken, economic. that all Venn many are be does knowledge. environmental, economic there genes mouse, the human was a how and human wanted diagram how Determine the sets many by where concepts. identify shared from e In are total. Determine and Sociology genes show human ‘overlapping’ many species. have solving c Venn how to four 2 diagram: common. these is sustainable. 1.1 Mathematically speaking 37 – 2 Relationships Relationships are the connections and associations between proper ties, objects, people and ideas – including the human community’s connections with the world in which we live. 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(mutualism), left). its on The toxin) anemone and the anemone. itself to a host like this parasites. relationship the benecial is eats resources organism food coexist symbiotic. organism anemone (which (below, its is must relationships or same one provides camouage seahorses and clownsh one the relationship waste suckersh turtle for relationships, such protects Ecological relationships, compete this the organisms oppositional Sometimes as living benet one (commensalism). for not may commensal benet from organism Corals shrimps and and but have anemones pygmy them. 3 9 Are we related? 2.1 Global context: Objectives ● Understanding and a Inquiry the dierence between a SPIHSNOITA LER Understanding ● Knowing ● Understanding ● Manipulating how ● relation F function ● Fairness mapping to nd diagrams ordered domain functions and pairs in a relation using the correct questions What are ● What is ● What are ● How ● D are 4 0 and depict information logically What look ● Communication ways to represent function? the the Can to do similarities relations determining related Organize dierent a between notation ATL development relationships? C range and and dierent if one a and dierences functions? ways relation is of a function another? relations that are not like? inequality be justied? functions A lg e b r A Y ou should already know how to: 3 ● substitute values into an equation 1 Find a x the = value 9 of b y x = = x when 0.25 2 2 Find the value of y when = 2 x 1 a x = 6 x b = 3 ● interpret and language builder of use the sets, basic 3 including Use set a set the notation real b the builder set of Relations, There For art ● What are ● What is are many example, can be HTML a dierent a ways to set and represent to that x write: is any of x’s such greater that than x is any zero. functions relationships? function? situations cause paired color mappings, notation such number integer F x’s can with the where be you paired artist, a pair with color objects an can or eect, be a The things. piece paired with HTML code of for blue-gray its The code. mathematics, if the rst object is x and the second object is is can write this pair as (x, and To ordered the write pair second an (x, term ordered y), the rst represents pair, rst term an give represents object the sets from that a the an object second pairs from a rst 777 system set. come from. ‘Set’ {house pets} and B = {number of legs}, then (dog, 4) is an ordered has many = {person} and B = {age}, then (Jack, 14) and (Juanita, 15) are ordered pairs. sphere of mathematics, do many terms Exploration outside pair. the A Set A contains available at used in 1 all your the students in your class. Set B contains the French sports ‘set’ school. and a List the members of set List the c Write members of set is in the 5 ordered German B ‘Menge’, both have pairs relating set A to set B, describing dierent students it which dierent than ‘set’ which outside sports for ‘ensemble’ meanings down In word A is b as other mathematics. 1 is 216. meanings = the set Examples: A by y). 16 an codes y, HTML In of of color represented you shade 608FB0. number possible In color this the scope play. mathematics. Continued on next page 2.1 Are we related? 41 of 2 Choose 3 other a List the b Compare Consider (George, members them these sets of to what A and each other ordered that and describe list ordered the pairs where History), (Cindy, these B set pairs, (Ann, History), Suggest could of Science), (Donald, a pairs A = students ordered created your class. pairs. by {student} (Enrico, in your and Science), B classmates. = {class}: (Matt, Music), Science). ordered pairs A B represent. George Science b This sets diagram A and B. shows Copy the the members diagram. of Ann For Enrico Histor y each line the orderedpair mapping element amapping 4 Construct 5 Decide on diagram A set elements in the These is B. two sets draw of This is diagram rst diagram that ordered the a, set a A Matt to Donald called Cindy Music diagram. you pairs shows represented in part element set mapping for mapping Each a the in in by set to for encounter from how an your these the oval, in real sets. in lines the pairs life. Write elements and elements ordered in or a step Draw down a 4 set are for 1c mapping ordered relation arrows second in are paired. drawn each pairs. from ordered pair relation. mapping diagrams representing four dierent types of relations. How each do diagram name? one–to–one So far, you However, same one–to–many have looked mathematics ordered also full pairs of that many–to–many describe relationships relationships that can be in real described in life. the way. Exploration 1 at is many–to–one Consider set A the 2 equation List the elements of b Draw mapping diagram and set 5} and + a A 4, x 1, set 3, = {0, a 2, y = set y 2, is where an x is an element of element set of the B. B to represent the relation between B Continued 4 2 2 Relationships on next page you think mapping got its A lg e b r A c List all d Using the the ordered ordered coordinate 2 the the where A, same a Dene set b Determine ordered c A if in possible, ii If not is , and can this draw possible, the any equation = you pairs If x as Consider graph real A = { the 2, 1, a List b Hence, c Draw set d all A Using of 1, the 2} = x is draw the + an set a where a A Use = , your equation b A Dene x and why relation relation can (as in Reect ● What to ● What a are on a x of is an set element of B. diagram to represent all the diagram. on a coordinate plane, where y y is , where an (x, of y) that set to x is element an of element set of the set B. represent this relation. B represent the relation between pairs as coordinates, plot these points on a plane. same and equation y is an a 2 x = y element of the coordinate , where of graph plane, set in x is an element of the set A, B. step where x 3 is to draw any the real graph of this number. B. dened and are points 2 = diagram either Exploration the represent these B knowledge be relation. not. equation pairs ordered on set where mapping 2 the 2, element mapping elements mapping these Consider plot this equation. this ordered coordinate 4 represent number. 0, list a y explain equation the and that coordinates, y 2 3 y) B i Draw pairs (x, plane. Consider set pairs a the 1) or discuss advantages by by listing giving the a set of specic ordered rule (as pairs in that make Exploration a 2). 1 and limitations of using a mapping and limitations of using a graph diagram relation? advantages to represent relation? ● In which situations is a mapping ● In which situations is a graph diagram better than better a than mapping a graph? diagram? 2.1 Are we related? 4 3 A It relation has ● a three a set of ordered pairs {(x, y) | x ∈ A, y ∈ B}. components: relation the or rule that maps x onto y for each ordered pair in relation ● a set A ● a set B A is that that relation Practice contains all contains maps set A the all onto x elements the y set B of each ordered pair elements. 1 ATL 1 Determine which many-to-one, a A = A = each c A = in 2 Find in A a to each of real-life Dene b Write set the of your in to {couples}, A a in in student {students student type in your their B = sets the to B class}, diagram best = their mother {number number B = in B and B each as relation in type and in of maps For the and the in the relation relations: and the relation B relation maps maps each each couple diagram. 1 the elements in set A to the elements B two diagram Hint: one-to-many, these siblings}, siblings mapping 2 3 of of B question that of each {mothers}, grandchildren for (one-to-one, matches {grandchildren}, their A class}, A situation down mapping many-to-many) {students maps b or equations that Look best back y = x describes at your + 2 and the x 2 = relation answers to y , determine between set Exploration A the = type and of mapping set B = . 2. x A function one A function value a is element there function can is a in relation set be where thought only each element in set A maps to one and only B one of as possible a number output machine, value. Such where a for number every input machine is called machine y The A function can be written as f (x) = y, letter most ● x is the input value, x ∈ y ● f is the output value, x often ∈ represent function, B letters is the name of the function that maps x to = y is read ‘the function f of x is y’ or just ‘f of x is y’. h such used are way of writing f (x) = y is f : 2 Relationships as g in problems more . than 4 4 other often involving Another a but y and f (x) is used A to ● f where: one function. A lg e b r A Linear f : x the equations, input and f ( If a the Using x the 5) ordered to = −3, pair domain maps The domain range generates. the f B is + 2, 3, are you the functions. can say output Function of called function function The x is elements a a = is You that 5. notation can f (3) You uses = write 5, could both f (x) = meaning also write elements x + that f (4) of 2 or when = 6 an equation. set of of y notation, example. one and as this function for in function The such + 2. x range is is is set A the the the also onto elements of set B, then set A is called range. set set of of called input all the values output set of that the values images function that of the the can take. In a mapping diagram, all elements of elements in domain are set, all and elements the domain is specied in the question. If not, it is assumed to set of real numbers, . If a function is dened as a set of ordered f (x)), the then the range Example Consider is domain the set is of simply output the set values of (all input the values values of (all the values of the the set. 1 this in mapping A diagram. B words what the the 18th Leonhard century, Euler, one relation of could in f (x)). Alice Write of are x) In a one pairs other and in the be range (x, the domain. Usually, the the function the most prolic represent. Charles Baby b Justify why the relation is a Diego c State the domain and range mathematicians in function. of history, the the introduced notation f (x) to Gabriel Toddler function. Pauline d Write the function for one of represent of a function x the Elsa ordered a This b day This each c in mapping which a pairs age care Domain: diagram. diagram group could children represent belong to at center. relation child this is is in a function only {Alice, Range: {Baby, g (Elsa) = one age Charles, In order to be a function, each element from the domain because must map to one and only one element in the range. group. Diego, Gabriel, Pauline, Elsa} Toddler} g was chosen for the function, since it represents the group a child belongs to. d Elsa is a Toddler toddler. A Practice 2 1 this Consider mapping B 2 diagram. 3 a Determine b Write c Find: if this relation is a function. Justify your answer. 2 4 the domain and range using set notation. 5 i f (1) ii f (2) iii f (5) 2.1 Are we related? 4 5 2 For each of i Write ii Justify iii State iv Write the in following words why the what the the relation domain down mapping one and relation is a could range. specic ordered pair in b brand represent. function. Chocolate a diagrams: the function. x Name Gender Joanne Girl c y Countr y 1 1 1 Neuhaus Belgium Côte James d’Or 2 Leonidas 4 Jessica 2 Toblerone Switzerland Jennifer Lindt 5 Hershey’s 25 USA Boy Joseph 5 Italy Baci Example State {(1, the 2), 2 domain (2, 4), and (3, 6), range (4, 8), of (5, the relation: 10)} In Domain = {1, 2, 3, 4, a list of ordered x-values. The In Range = {2, 4, 6, 8, a list of domain ordered 1 2 State the and range for each a {(7, 4), (2, 9), (4, 6), (8, 1), (5, b {(6, 2), (8, 8), (3, 7), (4, 4), (4, c {( d {(a, g), (t, e {(a, x), (a, 3, 1), Consider the all (5, c), 1), (s, y), set the ( = List ii Hence, list iii Draw mapping iv Use v Determine your w), (b, { (3, ( x), 2, ordered the 1), (k, z), i a 2, g), (a, A elements of diagram mapping to or not ( 7, (p, 1), (8, 1)} p)} z)} 1, y) 2}. that the diagram whether 4)} 1), 0, (x, 2)} k), (b, 1, pairs j, relation. For range (set relation this a to c: relation. B). the determine the relation represent represent to each relation which is a between type of set A relation and it y 4 6 = x b 2 Relationships y = 3x + 3 function. c y = set is. 2 a the domain written pairs, range 3 domain is the in is set the list of range notation. is the list of 10} y-values. The Practice pairs, 5} x B is written in set notation. A lg e b r A Activity With some range as by input this functions, simply and method, the it thinking kinds copy possible about to the values kinds that complete determine are this of 2x can you so values produced be can the any double f convention, function range square number, h can four have A functions on natural can A the Practice each in the square g is square only root. { y | y ≥ the Sothe 0, ∈ }. real domain of . the domain domain so any of the gives is Activity or the range show for largest the dierent dierent possible set possible restrictions you functions. of values that a function take. restricted State is used Using . positive can be value, is root You can output. since any of that as and Range value, domain domain table. By The the Domain x = of and Function f (x) is the domain is a subset of the natural domain of the function. 4 largest possible domain and the corresponding range 9 3 for function. 2 1 y = 5x 3 2 y = −4x + x y = + 12 5 2 4 y = 2x 2 5 y = 2 + 5 6 y = 3x y = 8 y = 9 2x x 3 1 15 32 7 x y = x + 1 1 10 y = + 1 x 2.1 Are we related? 4 7 Reect Recall the and discuss denitions ● Are all functions ● Are all relations ● If you ● What a relation and a function. relations? functions? answered Using C of 2 ‘no’ to either functions are the question to similarities above, explain express and dierences why. relationships between relations and functions? ● How are function So ● far, a you have function domain value ● a seen a there function relation is is 3 a a special For each Label to type one ways one exactly investigates of and one one-to-one of determining if a relation is a another? relation, only one output or a further where for element each in the element range. of the (Each input value.) many-to-one how you relation. can determine whether or not function. Exploration 1 dierent that: exists generates Exploration a is the related 3 mapping each graph diagram, with its draw a set of points on a coordinate plane. Use relationship. a new coordinate 3 3 for 6 6 10 10 1 1 15 7 2 2 3 3 19 9 5 one–to–one If 2 you are the many–to–one following steps to guide Determine which axis represents the domain, b Determine which axis represents the range, Determine a b Draw of your from the Looking a graph at graphs graph your of y show a whether = 4x graph, function. or not a y many–to–many you: a determine 3 try 19 9 5 one–to–many stuck, x = f (x). Suggest relation is how a you could function. 9. determine the type of relation this is. Continued 4 8 mapping diagram. 12 4 15 7 each 2 2 12 4 2 Relationships plane 3 10 on next page A lg e b r A c Draw a mapping ordered the pairs type possible d Decide of Hence, for your ordered whether pair or that decide it for not your to represent mapping relationship relationship e diagram the whether y = You mapping mapping graph = diagram, represents. this y 4x 9. until do Select you not are need only a few satised to list with every diagram. diagram conrms the type of represents. 4x 9 is a function. y 2 4 Here is the graph of = y x 5 a Determine which of the 3 four types graph of relationship this 1 represents. 2 b Hence, is a decide whether or not y = 4 x 1 function. 3 5 You a ● have function with a used two mapping many-to-one, ● with a then the The one if than line the the each relation vertical called diagram: then graph: point, more dierent (sometimes is a if for function a deciding from mapping relation is has a x to whether or not a relation is y’): diagram is one-to-one or function only one corresponding y-value, function. test: point, ‘a x-value if relation one methods is no a then vertical line function. the If relation intersects a is vertical not a a graph line at more intersects the than graph at function. 2 y = 0.5x 1.5 is a function, because no vertical y line intersects the graph more than once. = x is ver tical not line y a function, intersects because the at graph least one twice. y 4 4 y = 0.5x 1.5 2 2 0 x 2 0 4 x 2 2 2 4 4 4 6 8 2.1 Are we related? 4 9 Practice 1 Use the 5 vertical line test to determine which of Example Determine c y 5), x functions. y x x x 3 whether (5, 6), or (2, not 5), these (4, relations 6)} b represent {(1, 3), 2 = show y x {(2, graphs y y a these 3 d x 2 + y a (2, function 4), (3, from 3), x (4, to y 4)} 2 = 4 a 2 5 6 4 Draw a mapping diagram for the ordered pairs. 5 5 6 2 This relation is not a maps to both 5 and 5. function. This is a one-to-many relation. b 1 3 2 3 4 This 4 relation is c a function. This is a many-to-one function. y 4 3 2 y = x − 3 1 Draw 4 3 2 1 4 5 the 1 a graph vertical and line use test. 2 3 5 This relation is a function. Therefore, you No use the notation y = x 3 or f (x) = x vertical graph Continued 5 0 2 Relationships line would cross the 3. on next page at more than one point. A lg e b r A y d 6 2 x 2 + y 2 = 4 2 Draw a graph and use x 2 the vertical line test. 2 You This relation is not a can graph Reect and Representation which ● How did ● How does a ● Why Decide Give is you relation is Practice 1 discuss an something a it is MYP represent a of this vertical circle at lines more that cross than one the point. 3 related concept. It is dened as ‘the manner in presented’. relations representation is draw function. enable and functions you to in Example determine whether 3? or not function? important to distinguish between relations and functions? 6 which reason of the for following your relations are functions. answer. b a A 1 2 3 4 A B 4 2 0 2 B c {(3, 12), d {(9, 9), ( 16, (8, 7), 10), (7, (3, 5), 12), (5, 9), (15, (9, 3), 5), (3, (6, 12), ( 0 1 5 15, 1 1 5 7 5 3)} 12)} y y 10 9 8 2 7 6 0 x 5 2 4 3 4 2 1 0 1 2 3 4 5 6 7 8 9 10 x 2.1 Are we related? 51 y y 6 4 4 2 2 x 4 4 2 Reect and Justication evidence ● is used Where in discuss an to MYP related support the 4 a previous concept. It is dened as ‘valid reasons or statement’. example and practice problems have you used justication? ● How is a does justication Is ● Can it not important think you of a 1 Explain 2 If think to justify of some is number, why an Make for this element if Writing A up your see your they a example, ● f is the ● x is an ● f (x) ● ‘3x + get the is is whether or not a relation relation you is have a function? worked with that are is as tells ‘I by a the of you then square the result.’ of a of a write puzzle. notation. is called (input dened Then denition mathematical is function, number’ function domain f this this function you dening a expression values) as: as Write share f (x) = and 3x + function with others and have. specic that range 2, the it function. species (output the values). then: domain x’ what denition and function the of 3 something). think same corresponding usually = mathematically of ‘f add domain f (x) function element 2’ 5 2 a it, function. the the dened name read the domain a equations mathematical between if a of in write is is own function function This whether double (i.e. puzzle relationship For support 4 mathematically 3 to functions? Exploration x you function? ● ‘I enable of the function element this specied. specic If it does from to it is each element of the domain to range. function isn’t, 2 Relationships the f. When assumed to dening be the a set function, of real the numbers. A lg e b r A Example A recipe an x: states extra time f (x): 40 using the 4 chicken function weight the that minutes. of the cooking needs Express the notation, chicken time (in and (in to be cooked relationship dene the for 15 minutes between domain weight and per kg and plus cooking range. kg) Set in minutes) Neither the weight nor the the the input and context cooking of output the time variables problem. can be negative. Domain: The chicken will take at least 40 minutes to cook. Range: f (x) = 15x + 15 40 Check: Check f (1) = 15 × 1 + 40 = 55 f (2) = 15 × 2 + 40 = 70 Reect Think what If had you cooking of x is this sense in a real-life sense of When input the x = be of each the height a bad sensible meaning Yet, y = variable the that = 15 cooking the x × function = 0, 0 + in does 40 a are Good of a of 2 chicken kg (x) Do needs chicken needs plus the 15 30 40 more results min min + seem 40 + minutes. 40 min min sensible? = = 55 min. 70 = it Example make 40. For 4. sense what that the values domain (or real-life) or an denition do they constraints number Why but do not make chicken). the called variable age. kg worded represents Tina’s possible, 0 elements represent problem. and f (0) restrictions variable kg values. kg intended? with restrict to for mathematically (as These variables that context Tina’s would may problem. setting are all, are context easy per 5 denition values situation important at minutes? function real-life the values 40 1 A chicken is with A discuss input no time Sometimes A and minutes you in order on the situation, amount make it is within examples think to domain. are writing x = Tina denition? 2.1 Are we related? 53 min. Practice 7 Objective: i. use C. in both oral In these questions notation to for explain For each and the how a Express b Dene c written you the the (notation, symbols and terminology) function a and notation words such to express as ‘domain’, the relation, ‘range’, set builder ‘one-to-one’ function. 3: domain range how use range, is relation and carpenter to to and relation 1 language explanations. need domain the Explain A mathematical question domain 1 Communicating appropriate the using and range. based on relation charges his function is clients Decide the a notation. what real-life the constraints are on the context. function. a rate of €30 an hour, plus a single €40 fee The for each job. fee charged Express the relationship between time spent on a job and the to the placement € A bathtub water lled empties between the is time out with at a elapsed 120 rate liters of since 25 the of water. liters plug per was The drain minute. pulled, plug is Express and the pulled the and the relationship amount of water On in bathtub. a tropical account size of parcel a Evaluating a corresponds Example If f (x) f (x) = = 3x old So might it one 3x f (4) = 3 f (4) = 12 + × f (x ) = for of land, function to a given cost of a parcel additional and the means 15%. nal in the land is Express price nding element of that the $200 the the per client element square relationship of pays the 4 + for range meter. between 2, be €37 country, but another. Taxes the it. that nd the value of f (4). Start + 2 with the original 2 = 14 − 2 a Describe b Draw function denition. Substitute 8 a currency. domain. 2 4 x in words table of corresponding 5 4 the an in what with 5 + Practice 1 island, fees is on did their in and based countries 37€ 3 symbol client. often 2 of the what values output this that function shows values. 2 Relationships at does least to 5 the input dierent value. input values and the 4 for x A lg e b r A 2 2 g (x ) = x + 2 a Describe b Draw a in words table of corresponding what values output this that function shows at does least to 5 the input dierent value. input values and the and the values. 2 h (x ) = 3 x a Describe b Draw a in words table of corresponding 4 5 If f (x ) a f (3) If a In a p (3) = 7x − 3 , = triangle cases, are f and an given Solving an domain input two 5, or ( shows at does least value will the 1) = pentagon, generates see that corresponds is to 5 the input dierent value. input values when 5 Consider functions it a is specic is to called means element output the possible This given p (8) generate function a (0) d f (20) d p (10) nd: one values value. to Exploration f c input output equation c p (6) more you only that that function values. p (5) b function, this nd: b InExploration you values output p (4) certain what same nd the solving nding in the value. And output input the the in value. value if function. element of the range. 2 1 2 For each at = x For each For 4 Use a f (3). function, nd the a equation each your Evaluating one nd function, for between Solving f (x) function, the each value two = 7x This 12 is and called f (x) = x evaluating the function 3. solving 3 the input function to = of x such that f (x) = 16. This is called 16. whether there is only one possible input value. decide value function f (x) determine output ndings an when value and (nding (nding if a an the the function output value value of always value. of x, is a one-to-one Justify your f (x)) only gives given f (x)) can relationship answer. one give answer. more than answer. 2 f(x) = 7x 12 f(x) = x 23 64 8 5 8 evaluating the function at x = 5 solving the function when f(x) = 64 2.1 Are we related? 5 5 Practice In 1 9 questions h (x ) = 1 to 7, evaluate the function at the given values. 2 − 4 x In a h (0) b h (1) c h ( 1e, for d 2 3 f h (20) (x ) e = 3x h ( f (0) b d f (12) e (x ) f x in the a function. h (2x) − 5 a f a) substitute 1) f (4) c f (3x) f ( f 4) f (x + 1) = 13 a f (0) b d f ( e 25) f (19) f ( c x) f (20,000) f f (12x) 2 4 f (x ) = x a f (0) d f (9) +1 b f (5) e f (x c + 1) f ( f 5) f (4x) 2 5 f (x ) = x a f (1) d f (7) − 2x +1 b f (2) e f ( c 10) f (0) f f (3x) 3 6 7 f (x ) = 4 x − 2x +1 a f (2) b d f (3) e f (x ) = 3x f ( f ( 1) c 2) f (0.5) f f ( x) + 5 a f (5) b d f (3x) e 8 If f (x ) = 8x 9 If f (x ) = 10 If h (x ) 11 If r (x ) − 4 , + 12 , x nd f (x the nd = 15 − 2 x , f (10) the nd c + 5) value of value the of value f (2x) f a b of such such c f (3x that f (a) that such 2) f (b) that = = h (c) 12. 12. = 3. 2 = , x nd the value of d such that r (d) = 36. In 11 and 12 there 2 12 If f (x ) = + 5 , x nd the value of e such that f (e) = are If + nd the value of p such that k (p) = 4 2 1 14 f If , If p (135) that p (s) the value of q such that f (q) = 5 solving = = nd 5 Problem 15 1 (x ) = x south-east and p (180) = south, nd the value of s such north-west. In 16 If child(Olimpia) that m a must such be that function. 5 6 possible values. , k (x ) = x two 1 1 13 54. = Viola satised child(m) Explain in = and order you, your child(Arienne) for and child(x) reasoning. 2 Relationships to determine Share = be if in your William, a state function. your with condition(s) Suggest family ideas the a child(m) others. value = you of is 16, how many children can a parent have if child(x) function? is a A lg e b r A Recognizing D not So far, ● a ● if an is You What ● Can input not a have by a to specic a be that are generates a looked function. at its the lists at how However, to is more the look domain than decide it like? one and range output, the relation if a possible mapping to tell if a diagram relation or is a a graph function equation? 6 of equations below. NOT y x 4 For A 2 3x functions between FUNCTION = not justied? relation relation Exploration at relations function. looking Look are that: already represents just is do inequality know function that functions ● you relations each relation, x ∈ and y ∈ FUNCTION 2 + y = 16 2 2x + 5y = 9 x = 3(y + 1) 7 2 y = 2 2x + 3y 2 = 5 2 + x 4y 3x 4y 5 = 0 x y = 1 3 y = 1 2(x + 1) Based that on are 2 If 3 Based 8 the possible, on ● What input ● Why ● Are not ● above, and rewrite your arelation, Reect lists functions but and sort of each results, is not make those to of about the types ofequations not. look which equation discuss relations conjecture are equation suggest the a that like type a of y = f (x). equation represents function. 6 generate more than one output value for a single value? do those there relations other generate relations that more have than similar one output properties value? (and are therefore functions)? How does this relate to the ‘vertical line test’? 2.1 Are we related? 57 Summary In an an ordered object pair from a (x, rst y), set the rst and the term Another represents second The represents an object from a second relation is a set of ordered y) | x ∈ A, y domain that The has three a relation or rule that maps x onto y for range set A pair that in the set B natural contains all the x elements of values that relation contains maps mapping relation oval, in are and the set A diagram paired. lines rst all the y of is set pair function set A maps function or to set B onto shows Each arrows how set is are elements in the is to a can be x is the input ● y is the output restricted in the elements represented drawn the of from second by in a more an elements set for at function. the ‘f of = x y is is name set of input function is also the the set function of all the called the set generates. in the of images domain. a is the function largest can possible set take. domain is a subset of the natural and where only written value, x value, of read ‘the function. line more If than a test: if no vertical than one point, vertical line intersects one point, then the the line intersects relation the relation is graph is not a at a function is dened each one element element in domain in set that by (input as f (x) = y, the species a mathematical values) the and relationship range between (output values). B where: a function of the range that in the domain. means corresponds nding to a the given element element ∈ A y an equation that is a function ∈ B function that maps x to that y function f of x is y’ or nding the corresponds element to a of given the domain element in range. just y’. Mixed 1 the take. each the f (x) y function. means is is can that the vertical graph Solving f relation. relation one ● ● function domain Evaluating A a that expression A x elements. A ordered : each a A f pair The A a function elements domain a is relation A ordered ● of the values range the of a y each A ordered ● = components: of ● f (x) ∈ B}. output It writing pairs: The {(x, of set. values A way term practice Determine prince whether each diagram princess represents a relation or a 3 9 10 400 15 100 function. Justify your answer. 1 2 lord 9 lady 20 5 8 10 2 Relationships 225 3 8 a A lg e b r A y d y i 10 3 2 8 1 6 0 x 1 2 3 4 1 2 3 4 4 2 y j 20 0 2 4 6 8 10 x 15 y e 10 5 6 0 x 4 2 6 2 State the domain and a {(1, 1), (2, 4), ( 2, b {(3, 5), (4, 5), (5, c {( d {(1, range: 4)} 2 y 2, 3), ( 3, 6)} 2), ( 2, 5)} f 6 1), (2, 3), (5, 8)} 4 3 Find the a f (x ) c f (x ) = largest = 3x x 6 4 2 2 4 possible − 8 domain and b f (x ) = 3 d f (x ) = x 6 x 4 2 4 f x 4 4 e range: (x ) = x f f (x ) at the = x − 1 4 6 4 Evaluate each function given values: y g 2 a 10 a (x ) i 8 6 b = 2 − x a (2) b (x ) = 8x ii a (0) iii a ( 2) ii b (3) iii b (1) ii c (5) iii c (0) ii d (4x) iii d (2 − 4 4 i b (4) 2 c c (x ) = x − 1 x i c (1) 2 d d (x ) = 2x + 3 y h i d (4) 4 3 2 1 0 4 3 2 x 1 1 2 3 4 1 2 3 4 2.1 Are we related? 5 9 x) 5 Solve each function at the given values: 8 The table shows postage rates for letters and parcels. f a (x ) i = f (x) 4 x = − 2 18 ii f (x) = 0 iii f (x) = Letters 2 Weight less than Price 1 b f (x ) = x 50 1 1 f i (x ) = f ii f (x ) = (x ) = 2 £0.65 100 g £0.92 200 g £1.20 4 5 c f iii (x ) = − g x Small i 6 A f (x) 5 computer returns a = the Justify ii f (x) program number why this asks of = 1 you letters iii for in computer f (x) any that = 9 word Weight and less parcels than Price 100 g £1.90 200 g £2.35 500 g £3.40 750 g £4.50 word. program is a function. b Write down what this computer program 1 does is in function called ‘p’ for notation, where the program. a Draw a weights c p (horse) ii p (Mississippi) iii p (hi) b Decide price Find x such mapping of i p (x) What = is or whether the 3 ii p (x) = arrows show 7 A For 8 c p (three)? what hospital ground the stops at has the Justify b Find c For the each Justify x 10 a the the does of p (x) ground below the T (n) elevator function. domain domain, elevator hours. Write of T (n). suggest stops your at the that answer pairs. suggest a x? (including ground. times = day. possible in 24 each is ≤ above number times your ≤ oors T (n) ordered Hence, 3 oor oor of 0 oors largest during of 6 0 nth why number list 9 and average a oor numbers oor) gives d diagram and the to represent delivery the charge. the price weight determines determines the the weight. possible range choice. 2 Relationships of T (n). as a to your mapping diagram this. Determine function. f items that Add e £5.00 Evaluate: i d kg function whether this relation is a to A lg e b r A Review in Fairness and 1 Many context development universities decisions. paired The with takers, Family results family shown use in test of in one income the income a table their such as a admissions test by the variable were reported State input and the ($) Total 10 000 test score b Is 30 000 1402 50 000 1461 70 000 1497 90 000 1535 110 000 1569 130 000 1581 c Draw d Does this relation a 150 000 Car this diagram Explain of this relation. Explain an equitable action, if any, your or fair do reasoning. you think should be age, factors. of the For 22 in rate rates kind vary of car example, one by city greatly you male can depending drive drivers calculate multiplying their and under their age by on other the average $1000 1604 180 000 subtracting that from $24 000. 1625 a 180 000 mapping income Determine function? demonstrate insurance your and b of taken? annual a a mapping this What age family range 1326 3 Draw and output 2400) e a domain the relation. test- relationship? than and here: (max. More variable 1714 diagram and the whether or to total not this down annual represent test Write cost based on b State what c For the of his equation insurance age for (C ) the for average a young male (a). the score. relation is a males average function. C (18) under cost of represents. the car age of Then 22, insurance a is nd the C (18). annual function ofage? c Suggest reasons why this relationship d mayexist. Is charging age d Should their 2 The universities admission table shows population natural in use this decisions? the information If percentage dierent so, of countries world their the dierent driver a rates fair depending practice? on use of e State f Suggest valid what for C (21) reasons drivers represents. why this under the Then function age of nd is Percentage of world population Percentage of world’s resources Brazil 3 2 China 19 20 India 17 5 Indonesia 4 1 Japan 3 4 Pakistan 3 0.5 3 6 5 18 used Russian Federation United States 2.1 Are we related? C (21). only 24. resources. Country the Explain in how? and of 61 3 Logic A method of reasoning and a system of principles used to build arguments and reach conclusions Transpor t A farmer and a from He is travelling wolf. While eating needs puzzle the to he to is grain, cross a market with and river them, the in with a wolf a he bag can from of grain, prevent eating a chicken, the the chicken chicken. small Of only one other passenger at a course, time. overlook How the it the out to river? using get chicken the Can the number trips? 6 2 farmer the safely fewest of the grain, wolf of can other you himself, and the side work es sometim would a wolf sensible the in farmer the rst even logicians s: question be Why travelling place? with Lateral Three bill is friends $25. waiter in got as each $1 plus to total a Where original The of Logic different the swans Test: are are of $10 each kept gone the $5 so $2 he for and paid $9, So, adds up is in from the waiter? seems is a logical, but the outcome does not. error? core logical be part sure of nding supporting that swan philosophy. There are reasoning: involves more Every you If be I the have not, happy how reasoning page uses nding saw a you might the tanned most man that If could ones. deductive abduce divorced. to evidence evidence statement seen likely that change you is is that you supports nd, the true. white, a he saw your a test lot of your generating The so that means all money all swans hypothesis? new transport that facts puzzle by on the reasoning. involves with you wager involves existing reasoning and would $1 gave think The manipulating Abductive people, keeps The the white. white? facing up altogether. waiter here logic can Would Deductive got they reasoning Statement: they $27 the remaining types you and the $10. philosophy of statement. more divide contributed paid that that in Inductive a they $2 you study and waiter $29. $30 do bistro three back, eectively mathematics Which The so the has to between customer means $27 how $1 a the tip. back, which in give know person a lunch each evenly each himself Now, have They doesn’t change gives thinking looking at explanation ring had him of white once for on with reinforce If his married hands or facts them. skin been holding reasoning, known you nger, but later woman, it? 63 But can you prove it? 3.1 Global context: Objectives ● Masuring and ● th twn Finding th a Orientation Inquiry distan lin and distan twn a two ● points, F point twn two How CIGOL Finding th shortst ● Finding th midpoint twn ● Proving th midpoint formula ● Proving th distan distan from a point to a time do you nd th distan th shortst twn How do a you point nd to a distan lin? lin ● two and points? from ● space questions two ● points in How do you nd th midpoint twn points two givn ● How do ● How an points? you form logial argumnts? formula C D ATL Communication Mak infrns 6 4 and draw onlusions you prov and/or th ● Dos mattr ● How it muh th midpoint how ‘proof’ distan formula? proof is formula is prsntd? nough? G E O M E T R Y Y ou ● should plot points Cartesian already on know the 1 how Plot plane D ( points 4), and Describe ● apply Pythagoras’ 2 theorem T R I G O N O M E T R Y to: the 5, & the Find the Give your A (2, join shape missing 4), B (4, them up you length, answer to the 2), in have h, in C ( 5, 2), order. drawn. this nearest triangle. millimeter. h 5 9 ● construct from a a ruler a perpendicular point and to a line 3 On with plain which compasses and Using logic to not compasses point F paper, does P make that is cm draw pass to a point How do you nd th distan construct ● How do you nd th shortst two and P. a perpendicular twn P, through geometric ● cm line to a Use line a L ruler from line L deductions points? Logi distan from a point to a has lin? traditionally ● How do you nd th midpoint twn two givn onpt Logi in mathmatis Thr ar is th pross of rating a rigorous argumnt. studid mathmatis philosophy thr parts to any logial argumnt: premises, process, and Th prmiss ar ● Th pross ● Th onlusion is a fats way that of you know or manipulating ar thos givn fats, at th start. aording also a nw fat, whih you wr not rtain othr to was and ut usd lds omputr ruls. linguistis is is tru in suh you prinipls must On to also of agr somthing driv othr Deductive fats and logi has 1 On mm 2 Plot 3 Using 4 Now 5 Dsri, 6 Using valu a in and for. points plot th as agr with th prmiss and th pross, onlusion. logially, futur. th This pross togthr graph A (2, 1), masur point to papr, B (8, th D (14, thoroughly triangl you you of is you an known taking mak apt as prviously nw it as ddutiv tru and us it rasoning. known or provn ons. 1 squar rulr, is if provd th thm that th n reasoning putting th with rsults Exploration 10 stat ACD, masurd 9), and axs C distans (14, AB, for 0 ≤ x ≤ 15 and 0 ≤ y ≤ 10. 6). AC, and BC 1). as you alulat in draw stp an, th th shap lngth of ACD AC and ompar it to th 3 Continued on next page 3.1 But can you prove it? as sin, psyhology. Th a in conclusion. now ● n points? 6 5 7 Add a point similar to your diagram 8 Calulat th lngth of BC 9 Calulat th lngth of AB stp3. or Explain your and Masurmnt dtrmining How ● To ● What ● Hav In alulat th lngth of BC using a whih you and ompar it and ompar it think ar mor your to masurmnt your in stp masurmnt aurat: your is dos what is discuss an MYP quantity, in masurmnts mant you of y Rlatd you 1 ‘a to did aurat dnd dimnsion rlat dnd usd Conpt, or auray otaind 1 1 apaity Exploration dgr Exploration th you unit’ in using onpt masur th as a of mthod of unit’. Masurmnt? th ontxt ‘a dnd lngths? of Exploration 1? masurmnts? Pythagoras’ y B thorm points to on nd a th distan oordinat onstrutd 3 alulations. Reect ● to pross. a grid. right-angld twn First 3 you triangl. (4, 5) two A skth A ( 1, 2) 5 an hlp sids of you th nd th lngths of th shortr x triangl. B O A and B ar equidistant from O if th distans OA and OB ar qual. AO = OB A Practice 1 1 Find th distan from (4, 2 Find th distan from ( 3 For 2) to (7, 1) to 6). Mak th points a Find th b Roin PQRS c P (10, distans says: ‘th must Roin’s 13), a logial 3, Q (17, PQ, QR, lngths pross Premises: Conclusion: Explain 6 6 fault in 3 Logic and QR, a four 13), and S (17, 11): SP RS and SP ar whthr lengths are quadrilateral Since PQRS th R (24, Dtrmin The process: 11). all qual, Roin is so th shap orrt. was: If Reasoning 37), RS PQ, squar.’ (2, Roin’s PQRS is a has has four square. logi. equal. four equal equal sides, sides, it is then a it is square. a square. a skth. G E O M E T R Y 4 a On 10 V (4, mm squar graph papr, plot th points O (0, 0), U (22, 8), & and To 23). to b Zah T R I G O N O M E T R Y laims that th triangl OUV is ‘show’ quilatral. using Without masuring, dtrmin whthr or not his laim is or tru. xampls diagrams; ‘prov’ 5 a On suital axs, plot th points A (41, 99), B (99, 41), C (99, 99), E ( 41, 99), F ( 99, 41), G ( 99, 41), and H ( is a to muh 41), mor D (41, mans dmonstrat 41, rigorous 99). produr. b Show that c Mark d Dsri e Vrify f To any all lins th that what points ight of points symmtry rotational would ABCDEFGH omputr Problem to quidistant of th otagon symmtry ABCDEFGH xtnt ar it is not a of th rgular appropriat rprsnt a from th origin, ABCDEFGH otagon on (0, 0). your diagram. ABCDEFGH otagon. to rgular us th otagon oordinats in print or of on th a srn? solving Th 6 In th onstllation hors’s alld ody ‘Th ornrs on ( a 4, of is Cartsian 1), and Pgasus, rprsntd Grat Th of Squar’. Grat plan (0, y Squar at ( 1, th four Th of an 5), (3, namd stars stars at onstllation Pgasus wingd th Grk drawn myth, 2). killd Show that Th Grat Squar of aftr ths proprtis of a All sids ar b All angls th th th Prsus Gorgon (whos squar: sam was snaks), lngth was ar to whn Pgasus hair a in mythology. Mdusa has th hors Aording 2), is mad of Pgasus orn from hr 90° lood. c Opposit sids Exploration ar paralll 2 y Th diagram shows th point A(4, 7). A 7 1 Writ down 2 Liy says, th distan from A to th x-axis. 6 5 ‘Th point (2, 0) lis on th x-axis. 4 Pythagoras’ thorm tlls m that th distan 3 from A to (2, 0) is units. 2 1 Thrfor th distan from A to th x-axis 0 is 7.3 units.’ 0 Explain 3 Writ and 4 whthr down th not down of point th on this distan oordinats Writ th th or of lin x a from th distan th is A point from = logial 1 A that to th on to is 1 2 3 4 to A 5 x argumnt. th th lin lin lin losst y y x to = = = 5, 5 1, that and is losst th oordinats A Continued on next page 3.1 But can you prove it? 67 5 6 Find th oordinats Find th shortst Find th oordinats that 7 is losst to of distan th shortst Find th oordinats is Find losst th Reect to from th distan on A point to th lin th on y lin th = y lin = x x + 1 + 1. with that is losst to A quation of from th A point to th on lin th . lin with quation y = 7 2x A shortst and of point A Find that th distan discuss from A to th lin y = 7 2x. 2 y A For Exploration 7 2: 6 ● What diultis did you nountr in stp 7 5 ompard to stps 3 to 6? B 4 ● Suppos you ar trying to nd th shortst distan 3 L from A to a gnral lin L whos quation you don’t 2 know. 1 0 If B is th point aout th lin on L losst to A, what an you say x 0 Th shortst masurd You it is an Suppos that this a logi to you you an you that lin this a that in givn disovr rst this th assumption you your fat 1 2 3 4 AB ? prpndiular stalish an If th twn lin us mak assumption. tlls and distan along us tru, L lin to is and th a point not on that lin is lin. tru. On you hav dtrmind that futur. and that thn som assumption som of was valid your not ddutions ddutions tru. This is ar asd on untru, alld proof y ontradition. ‘Proof ’ mans Mathmatis, rsult will a dirnt proof always susquntly supports vry a is It disprovd. ut vidn is things roust tru. hypothsis, ontraditory a is In in Sin logial prmannt, Sin, whih ould and Mathmatis. argumnt, whih and if a proof ‘proof ’ is a ody susquntly In guarants is of valid, it that a annot vidn ovrturnd that if found. ATL Exploration 1 On plain 2 Using 3 papr, draw ompasss prpndiular to and L a a and lin L rulr, passs and a point onstrut through a A that sond is not lin on L′ – th that lin. is A Continued 6 8 3 Logic on next page G E O M E T R Y 3 Lal th To show not th 4 If that P losst P is ls. 5 point not and Triangl th Sin losst anothr 6 L ABP L is th A If y in is this A on L. P L, start following losst Lal y supposing that P is point it must li somwhr B sntns: triangl, , it is < to th AB, and angl ∠APB is whih AB is th of triangl ABP, sid. ontradits th assumption that B is th point P your a sid longst own to words A ontradition ours, Point A th lin a losst produing Practice 1 AP losst proof and thn on is mans whih to mt . ∠APB Explain lins point point, point omplt Thrfor on two losst aus whih th T R I G O N O M E T R Y point. th Draw Copy is whr & rsult thn th lis how on a involvs that is this lin applying oviously original shows that th prpndiular a fals, assumption logial or point to L pross ontradits must hav n on through to a your A hypothsis assumption. inorrt. 2 has oordinats (5, 8). Construt th lin through A that is You prpndiular to th lin y = 4x + an dynami Find th Lin L shortst distan from A to th lin y = 4x + has quation y = 3x for L has quation y = has oordinats 8 or a GDC 3. 1 Lin gomtr y 2. softwar 2 us 2. 2x qustions and 2 3 2 Point B Dtrmin Justify whih your lin (2, 9). passs losr to point B answr. 1 3 Draw th lin L with quation y = 4 + x 2 Add th points Dtrmin Justify whih your Problem 4 Air tra airport A(2, 9) and point is B (7, losr 3) to to your diagram. L answr. solving ontrollrs and any ar othrs in that harg y of plans ovrhad on taking th o way to and landing anothr at thir dstination. Mak Whn plans om into thir airspa, thy trak thm using a sur you oordinat us logi to justify systm. your Plan A is at (12, 5), ying towards (21, 12). Plan B is at (9, 8). Y our a Find th shortst distan from Plan B to Plan A’s answrs. ight path. justiations should dout b Suggst what othr information (not inludd in th oordinat air tra ontrollr nds to prvnt th plans gtting too to no whthr systm) your th lav as los answr is to orrt. ah othr. 3.1 But can you prove it? 6 9 Exploration ATL 1 Using 2 Find 3 Compar dynami th Crat th othr th 5 Us of your points 6 Vrify 7 Points P Vrify of (7, Reect 11) Q your and Gnralization th midpoint M to th of points A (10, 6) and B (2, 8). AB oordinats of points A and B. noti. th stp and and nd twn th th midpoint. 4 midpoint of oordinats (Hint: th prdit ah of onstrut a pair. th ndpoints tal of th formula th of N, th midpoint softwar. P (a, oordinats givs discuss oordinats 15). oordinats for mans to D (19, using hav formula that of points of in answr and a th plot midpoints.) ndings C M, rlationship and your Suggst 8 pairs th you oordinats ndpoints of softwar, oordinats anything Invstigat and gomtry oordinats Dsri 4 4 th b) and of th orrt Q (c, d). midpoint oordinats of PQ for M and N 3 making a gnral statmnt on th asis of spi xampls. ● Whr ● How dos ● Why is Th in Find th M M = hav of (a, b) to nal vrify and you (c, d) a gnralizd? you to prdit? gnralization? is . 1 th of A(3, midpoint 3 + 9 6 + 18 2 2 of 6) and B (9, 18). AB Use the midpoint formula M = = important midpoint 4 gnralization midpoint Example Lt it Exploration (6, 12) Practice 3 1 Find th midpoint of A(14, 2 Find th midpoint of C (5, 3 a Plot b Find c Commnt th points th midpoints on quadrilatral 7 0 A(2, your 7), of 6) and 3 Logic 20). 13) and D (10, B (3, 10), C (6, AC and answrs ABCD B (18, to 8). 11), and D (5, 8). BD part b. Explain what this shows aout G E O M E T R Y 4 Triangl a PQR Show L, M, that and N ar Writ down c Show that Show with that vrtis triangl b Problem 5 has th th P ( PQR 2, is of oordinats LMN Q (2, 3), and and RP R (6, T R I G O N O M E T R Y In qustion 3). isosls. midpoints triangl 3), & is PQ, of L, QR M, and rsptivly . N isosls. solving th midpoint quation y = 2x + of points U (7, 11) and V ( 2, 1) lis on th lin 1. that 6 As you saw in Prati at ( 1 qustion 6, th ornrs of Th Grat Squar th Show ar that Th 1, 5), Grat a Diagonals ar b Diagonals ist Using C (3, 2), ( Squar 4, of 1), and Pgasus (0, has show of oordinats Pgasus 5, midpoint’s satisfy 2). ths proprtis of a squar: th quation th lin. of prpndiular ah logic general ● How do ● How an anothr to prove claims and rules you form you logial prov th argumnts? distan formula and/or th midpoint formula? You will nountr mathmatis, ‘If … hlp you you to Eah why then … to stp of a in valid. argumnts vryday is snsil othrs logial is a form your argumnt If a of stp many Any logial disions. that in lif. Th idas with Thinking xplain your not th just in strutur logially logi will will hlp valual. ontain to situations; pross argumnt. aility ar should annot dirnt thought a justid, simpl you justiation won’t know if for it is tru. pross known A mak stp nssarily logial also therefore…’ prsuad th Th ut as of justifying a laim y providing stp-y-stp rasons is deduction deductive ddution Reect argument to draw and Justiation is a is any proof or olltion of rasoning that uss onlusion. discuss dnd as 4 ‘Valid rasons or vidn usd to support a statmnt’. ● What ● Why dirnt is typs justiation of justiation important in hav you sn so far in 3.1? mathmatis? 3.1 But can you prove it? 71 Exploration ATL You hav distan for th 5 alrady twn distan shown two that points. twn Pythagoras’ In two this points xploration, P (x 1 1 In th lvl diagram, with P point and is Q is thorm , y 1 ) and you P 1 will (x 2 horizontally vrtially an , y 2 usd nd to a nd th formula ). 2 y 8 alignd 1 with P 7 2 P (x 2 , y 2 ) 2 6 a What typ of triangl is P QP 1 Justify your ? 2 5 answr. d 4 b Writ down c Hn th oordinats of Q 3 writ down th lngth of Q P Q 1 2 P (x 1 and P Q in trms of x 2 , x 1 , y 2 , and , y 1 ) 1 y 1 2 1 d Us ths lngths to nd th lngth d 0 of P 2 In th x P 1 1 2 3 4 5 6 7 8 2 rst diagram, you assumd that P was aov and to th right of You 2 P . Suppos instad that P 1 was low and to th lft of P 2 distan formula would . Show that skth 1 not ould th th two hang. othr possil arrangmnts 3 Suggst othr possil positions that P and P 1 ould tak rlativ to ah 2 P othr. Explain why, for any positions of P and P 1 rmains Th (x , 1 th distan y ) and formula (x 1 Whn , y 2 Reect P and ● Dos ● What ) is stats givn that th distan, d, twn y P discuss ar th lvl distan happns to 4 1 distan th a (3, 11) b ( c (103, 3, and 8) 9) Problem Show point that 3 Show 72 two points 5 horizontally: formula point Q, still and work? th triangl P P and and twn pair of points. 15) (2, ( ah Q? 2 16) 17, 208) solving 14), Q (11, 12), and R (13, 8) ar all th sam distan from 7). nd that (6, P (7, C (6, Hn formula 2 Practice 2 distan . 1 Find th 2 and 1 , 2 sam. th th ara points of F ( 3 Logic th 6, irl 5), G ( that 4, passs 5), and through H ( 5, 9) P, Q, form and an R isosls triangl. 1 and P . 2 of G E O M E T R Y Activity: Objective: iv. Proving C. the midpoint & T R I G O N O M E T R Y formula Communiating ommuniat omplt, ohrnt and onis mathmatial lins of rasoning The proof midpoint sections Th to Q (c, d) Copy gaps is you you give give clear a complete and concise and coherent explanations proof and of the details in the in this proof that laims th midpoint of points P (a, b) M has that and if help complete. th proof prov will formula, you Complt and outline two M is parts: rst, quidistant omplt th proof to prov from P outlin that and M lis on th lin PQ ; sond, Q. low. Theorem: Draw Th midpoint of points P (a, b) Th Q (c, d) is a diagram to show P and Q on a grid. and position of P and Q on th graph is not M important – just don’t put thm in th sam pla! Proof: PMQ and is th a straight gradint lin of if th MQ ar gradint th ofPM sam. Show larly that PM and MQ hav th sam gradint. Sin a th gradints straight ar qual, PMQ is lin. Us Thrfor P and Sin and M is M is quidistant th distan formula to show MQ _____________________________________ ______________________________________, th midpoint of PQ. A squar marks th nd of a proof. 5 a Find th midpoint of A(3, b Find th midpoint of A(14, 9) and 2) B(7, and 3). B(6, th proof 11). also Show that th points A (2, 5), B (4, 19), C (14, 29), and D (12, 15) nd you s short a = from At 2 MP Q. Practice 1 that of a might ‘Q.E.D.’ for quod erat form demonstrandum, a rhomus. maning b Find th andDA c Show d Find oordinats E, F, G, and H, th rsptivly. that th Hn of EFGH lngths dsri th EG of AB, BC, CD, whih ‘that was to dmonstratd’. forms of midpoints a paralllogram. and shap FH EFGH 3.1 But can you prove it? 73 3 a Plot i th points Show non ii Find that of b Show Considr 8), of sids B ( th ar DA 4, sids of E, Find RS, that EFGH four points ii Prov Reect ● How or ● 4 forms P (x Whn of th (7, that and is is th thy sit , a y th 33), Dtrmin F, ah G, and th D (28, sam lngth, Givn th H, th midpoints to At ), Q (x , y 2 T, U, a 6 Copy and of AB, BC, ), R (x 2 V, , y 3 and W, ), and S (x 3 th , y 4 midpoints ). 4 of PQ, QR, paralllogram. rlatd and twn idntify th 3600 hight to nding th avrag ( Wst bce, 36, th sit, th and thy whr It ar has lngth statmnt is 3b? mark artfats Knnt thr 41). twi a 3a Long thr n of tru. o with found Barrow in hamrs said its it ar that oordinat kp England, at thy a and th a a grid rord grav oordinats form an isosls as. Justify your answr. solving points th that paralllogram. A(a, b) and B (c, d), prov that th point lin sgmnt omplt th AB in th following ratio 1 : sklton 2a + c 2b + , divids and othr. 5 28). 6 xavat asily whthr Problem of midpoint rlationship an with ar and man? ak (17, triangl ABCD to 1 forms discuss forvr. dating 9), TUVW nding 28), rsptivly. arhaologists that sit oordinats SP arithmti What so th and of C (16, rsptivly. 1 i 20), paralll oordinats CD,and iii non th th A (0, 3 d 3 2. proof. Tip C B Two said if points to thy ar ar coincident in th D A sam thy Givn: lin sgmnts AC and BD; th midpoint of AC is oinidnt with pla, hav this th th oordinats. midpoint Prov: 74 of BD. ABCD is a paralllogram. 3 Logic is, sam G E O M E T R Y & T R I G O N O M E T R Y Theorem: If th forms midpoint a of AC is oinidnt with th midpoint of BD, thn ABCD paralllogram. Proof: If lins AB and CD ar paralll and th sam lngth, thn ABCD is a paralllogram. Lt th midpoint Thrfor Lt th th of AC hav oordinats oordinats of A of oordinats th (x midpoint , y A By th midpoint (X, ), B Y of BD (x A ). , y B ar . Think ) Provid th information snsil you notation Us th midpoint x-oordinat . for Now Th gradint of AB Th gradint of CD is givn y nd is givn y thr valus y . will mor of C Thrfor proaly xprssion arfully of C formula in trms to xprss of x givn y rsults whih dsri and AB and CD Sin for to th show nd to writ gradint that it of a CD that maths th simplify gradint you may nd to simplify a , th points O (0, 0), A(a, a, b, c, d ≠ 0, 2d) and D (c, d) form a Presentation ● Dos ● How ar latr. not know that . b), B (a + c, b + d), and C (c, d) form c ≠ and a ar w solving b Assuming mt yt two xptd nountrd it mattr muh dirnt Thy prsntd. dirns it of AB ompliatd paralllogram. Hr x ompliatd and . and Problem D th D xprssion. C (2c, th X . Again, 8 and . is a D . You Prov and . and 7 C givn. A Similarly, Thrfor ar B formula, and aout to proofs undrstand worry trm if th points A (a, b), B (2a, 2b), the as is prsntd? nough? Isosceles you th som congruent that proof proof is of prsntd Don’t th ar ar ‘proof’ prov trapzoid. of how , d triangle might proof – words for, for nd for ar theorem, thm now, in just whih – What you txtook. look unfamiliar xampl. a will You ar at how th proofs you may not hav similaritis and thr? 3.1 But can you prove it? 75 Theorem: those If sides Proof two are sides of a triangle are equal then the angles equal. 1 C α β D A Givn Lt In ∆ABC th with istor ∆CAD B and AC = BC, ˆ ACB of ∆CDB, mt th triangls = BC, CD = CD, ar ˆ A = that at ˆ B D (Givn) (Common) β ; = ongrunt ∴ Proof AB AC α ∴ prov ˆ A ˆ B = Q.E.D. 2 C D A Th triangl vrtx Draw CDA CD in so is That angl as th th ar of CA to two AB ommon is, ΔCDB sids any = isosls CB. ist Prov ∠C , triangl, that forming ∠A two = with ∠B triangls, CDB istion; sid rprsnts and and Thn of C B AC to two qual ΔCDA, triangls, = oth sids to is and = and ∠BCD , CD = y CD, dnition as triangls. and two ∠ACD givn; th sids hn inludd and th th two angl of inludd triangls ar ongrunt. Thrfor, triangls, 7 6 as ∠A orrsponding = ∠B , as was 3 Logic parts to of ongrunt provd. this opposite to G E O M E T R Y Reect Disuss What ● Whih ● How good inlud out so discuss osrvations strutural proof do proofs dirnt. A your ● Both and you know inlud Proof proof 2 is it a asy think th to oth would th logi th Proof usd xampl, proofs proof ut wordy; (for othrs. do diagram, dsri is with whn vry justiation that you T R I G O N O M E T R Y 7 lmnts do & hav? asir is to undrstand? nishd? prsntation 1 to has far mov prviously of fwr from th on provn two proofs is vry words. stp to rsults) th and nxt, will will laid follow. Summary ● Deductive prviously thm ● A togthr and OA reasoning known B and ar OB to or is th mak nw equidistant ar pross provn fats of and taking ● A putting ons. from O if proof logial rsult th y ontradition pross that is assumption qual. a If this must involvs hypothsis oviously assumption. distans to fals, ours, hav or th Th midpoint of (a, b) and (c, d) is B original a Th pross of stp-y-stp AO = justifying rasons is a laim known as + c b + d , O ● y 2 2 providing deduction OB ● A A deductive of rasoning argument that uss is any proof ddution to or olltion draw a onlusion. ● Th lin th shortst is distan masurd twn along a lin a point and a prpndiular to ● Th d, lin. distan twn formula two stats points (x , y 1 that ) th and givn 1 Find y 1 distan twn ah pair of points. 3 Find th giving a (0, 0) and (5, 12) b (1, 4) and (4, 8) a 2 (5, d ( Find 7) 3, and 12) th (11, 3 x − x 2 1 ) y ) is 2 + ( y − ) y 2 1 and (4, distan giving signiant a (4, 8) twn b (14, c (1.5, 8) and 4.6) your (10, ah answr pair orrt 13) (17, and whol a (2, b ( 3, c ( 3, twn answr in th ah form pair n , of points, whr numr. 7) and (6, 15) 9) and (5, 2) 12) gurs. and distan your 7) 3) (2.3, 1.8) 5) and ( 9, 14) of 4 points, ( = , 2 2 practice th c d distan, (x 2 Mixed a your inorrt. ● a produing ontradits thn n applying and Find th midpoint of ah pair of points. to a (4, b ( 3, c ( 3, d (2.3, e 1 1 , 2) 4 9) 12) (5, and 5.9) ( and (6, and 5) 3 and and 1 8, ( 1 , 2) 3 14) 3.6, 11.2) 2 3.1 But can you prove it? 77 n is 5 Prove form 6 that an Thr B (1, points 4), Show 7 Point lin th and that A points isosls hav C ( th has (0, 0), and (3, Th 4) {1, A( 4, 1), a 6). points A (6, oordinats 5, that Sudoku 2, 3, By form is an (3, isosls 5). to onsidring that it = −2x Find y 8 = A th −2x has (4, + qustion us th st is th not positions possil of to th 1s and omplt 2s, this lin 4 2 2 1 3. shortst + this th th 1 y in puzzl: triangl. Construct prpndiular puzzls 4}. show oordinats through 0), triangl. 3. distan Giv your oordinats ( from answr 1, 3) and A to B to 1 th lin dp. has oordinats 1). 3 Determine y = whih point is losr to th lin x 2 9 Givn th points th point 3a 10 in Point th A c 3b + d , AB + A (a, has : B (c, d), prove 1 that divids th lin sgmnt 4 1 and 4 ratio b) b Copy this grid: 3. oordinats (a, b) and point B has 1 oordinats M is th (c, 4 3 d). midpoint of AB 4 a Find th oordinats of b Find th distan AB c Find th distan AM d Hn, M 1 prove that AM = AB 2 2 11 ABC and is a triangl C (9, with vrtis A (1, 0), B (5, 0). i a 1 9) Show that triangl ABC is Explain how right-hand b Find th oordinats of th midpoints of sids of Show that Hn determine th midpoints of th thr sids othr ar th vrtis of an isosls Show that th isosls triangl formd 8 midpoints squar of th sids of ABC In a Sudoku has Most Deduce 8, 9}. puzzl, puzzls playrs us th work st with {1, 2, a 3, st 4, Evry 78 th th possil positions of grid. answr. th digits that should appar in th lls. row, vry squar olumn, must st. 3 Logic ontain and all solving of 5, Point X has oordinats (4, 7) and of AB. Givn that A has vry of th is th 6, ( in th in units. mdium-sizd digits 2s rmaining midpoint 7, top ara 13 digits. two your Problem 12 th 2. from grids th that a triangl. iii d rtain ontain of Justify ABC must ABC th c an ornr th ii thr you isosls. 3, 11), nd th oordinats of B oordinats G E O M E T R Y Review in ar Short in a luky Jams in space nough Platinum dirnt T R I G O N O M E T R Y context Orientation You & loation. to - and hav found sourg Can time you of th th nd only svn thm all? surviving sas. (On H th opy has of a urid map, on trasur many unit map pis quals of on lft y th trasur notorious on th pirat island - ah lagu.) 14 13 Dolphin 12 Beach Mermaid 11 Smuggler’s Cove Pool 10 Grey 9 Skull Cliffs 8 Pirate’s Rock Forbidden 7 Port Falls Kaspar’s 6 Trader’s Cave 5 Bay Handyman 4 Hills 3 Falling 2 Palms 1 0 1 1 Th Tsarina’s Rok. it is It is from as Tiara far is from Falling 2 3 urid Skull Palms to 4 5 du 6 wst Rok to Kaspar’s 7 of th 8 9 Skull Tiara 10 11 12 13 14 15 16 17 18 19 20 5 To nd your as st Kaspar’s Cav. travl Find th oordinats of th pla whr Tiara is Th wrk of th halfway is to Purpl Porpois, a ship that 200 gold twn Falling douloons, Palms and is xatly th Handyman 6 Hills. Th oordinats of th Purpl If Skull Rok is th losr Falls, two point Pirat’s halfway Clis. Port, From and from thr, thr th found. oordinats to Tradr’s to thn lagus my ast of prizd Justify pik Bay of th Cursd Mdal of your answr. from th Bliz right is urid dp - so pla. th rout Silvr Mrmaid straight from Falling Palms to th than Cutlass Clis, Pool. If stop at th point that is losst to is Kaspar’s urid Bounty Gry Foriddn th Gry snd Porpois. On 3 to to th Caraas, halfway sur Find to of sank Caraas. arrying navigator Cav Mdal urid. Find 2 Cursd th mdal Tsarina’s th Cav. Had on lagu wst and dig not, dp! it is urid two lagus wst of Mrmaid Pool. a Determine th position of th Silvr Find th distan Kaspar’s 4 Th Emrald Crown, whih I lootd from tom, has n hiddn in a If you at an on nd of th th markd orrt sits sit, Find on you th will th distan tru loation of th Kaspar’s Cav from th Clis. th Gry Emrald Explain orrt how as rown th is as Falling Dtrmin th c far th d away Palms Hn loation you know Explain lin of show Falling losst ar from this is th only possil e Hn from that Gry Palms how to midpoint Crown. loation. Gry Clis to Cav. map. nd and from th to ruind trasur. Th from Palms Cav. Kaspar’s uilding Falling an b anint from Cutlass. this tlls Kaspar’s Falling of th Clis, form an you Cav Palms that that to Kaspar’s isosls th lis Gry Cav triangl. point on th Clis is th lin. determine th loation of th Bounty Bliz. 3.1 But can you prove it? 79 4 Representation The manner in which something is presented The Which representation is b est best? may Car tesian coordinate plane tation represen Mapping want diagram depend to what on show or to you nd out. y 0 4 1 2 2 0 3 2 x y 2 0 2 2 4 x 6 2 4 Linear y = equation 2x − 4 6 Table of values 8 Which representation ● that the ● that f(1) ● that the function = best is x 0 1 2 3 4 5 y −4 −2 0 2 4 6 shows: linear −2 y-coordinates increase by 2 for every increase in x? C Is a picture thousand ABCD to CD Angle ● is and How a 70°. does you Could AB perpendicular = Find drawing solve you a words? quadrilateral. ADC help ● a wor th this solve it to is BC angle a parallel B DAB diagram D 70° problem? without diagram? A 8 0 Representation in symbols Bayu-Udan Jabiru Challis Pufn Gove T oms Weipa Gully Ranger Browns I N D I A N Blacktip O C E A P A C I F I C N McArthur Cockatoo River Island Merlin Argyle Mt O C E A Garnet N Ellendale Lajamanu Centur y Balcooma Northern Mammoth Coyote Sarseld North West Shelf Ernest T erritor y Granites Mount Henr y Pajingo Isa Y arrie Cannington Osborne T win Y uendumu Hills T elfer Nifty rop T c of Capr corn Bowen Deepdale Brockman Y andi 2 Mt T om Paulsens Mereenie Kings Canyon Palm Valley Mt Whaleback Paraburdoo West Angelas Orebody Basin Queensland Hermannsburg Price 29 Plutonic Western Moomba-Gidgealpa Magellan Jackson Australia Moonie Lake Danot Lawlers T allering South Peak Sunrise Golden Ipswich Eyre Challenger Dam Grove Beverley Walkaway Australia Olympic Dam Leigh Creek Endeavour Dongara Koolyanobbing Super CSA Pound Broken Downs St Gunnedah T ritton Pit Wilpena Emu Hill Ives New South Hunter Middleback Range Northparkes Singleton Newcastle Mount Darling Millar Cowal Snowtown Cadia Western Range Wales Southern Cathedral Rocks Collie Wattle Point Victoria K E ACT Y Snowy Bendigo Mineral resources Energ y Dartmouth Stawell Eildon Coal Lake Bonney-Canunda Kiewa Challicum Ballarat (aluminium) La T robe Valley Hills Oil Copper W Mountains resources Bauxite N Queen Victoria E Market Bass Diamonds Natural Gold Uranium Iron Solar Strait gas S 0 200 400 600 km Woolnorth Beaconseld Savage ore power station River Reece Roseber y Mt Lead and Wind zinc power Lyell Henty Poatina John Butters station Gordon Hydro Silver Maps contain terrain. ones symbols Which that are of the used in that represent symbols places below other power features do than you T asmania station of the landscape recognize? Are or they maps? 81 A whole range of things 4.1 Global context: Objectives ● Categorizing Globalization Inquiry data and sustainability questions ● What ● How are the dierent types of data? F ● ● Constructing stem-and-leaf diagrams are the tendency Calculating quartiles, interquartile the range and SPIHSNOITA LER ● Constructing ve-point Identifying ● Comparing of central the ● Giving ● measures range ● a dierent calculated? summary of box-and-whisker a set of data C diagrams ● How distributions measures data? How dierent you outliers do describe do compare ● Should ● How we dispersion help representations data ignore of you help sets? results that aren’t typical? D ATL do individuals stand out in a crowd? Communication Organize and depict information logically 4.1 4.2 Statement of Inquiry: How quantities are represented can help to establish underlying relationships 6.2 and trends 8 2 in a population. S TAT I S T I C S Y ou ● should nd the and range already mode, of a median, set of know how mean 1 1, b Representing ● What ● How are the the range a F sets dierent of types of mode, of 3, these 5, 3, 6, median, data 9, 8, mean and sets. 3, 5, 6, 4 22, 21, 19, 20, 18, 19, 21, 19, 20, 19, 19, 22, 19, 21, 17, 16, 14, 22 data data? Data are the dierent measures of central tendency involves collecting raw data, organizing the data into is the and analyzing the plural Latin word visual datum representations, the calculated? of Statistics P R O B A B I L I T Y to: Find data A N D meaning data. ‘a piece of information’. Qualitative type) two ● using data describes words. a certain Quantitative characteristic data has a (for numerical example: value. color There or are types: Tip Discrete data can take can be counted (for example: number of goals scored) or In only certain values (such as shoe order to statistical analysis, continuous ● Continuous data can be measured (for example: weight and can take any numerical of Categorize state each whether it of 2 Time 3 Color 4 Numbers 5 Maximum 6 Heights 7 Dress sizes 8 Daily intake 9 Number for each of of data cars a car degree accuracy. to through cross eyes in girls in in an in each your your protein, milkshakes milkshakes or quantitative. For quantitative data, continuous. in intersection intersection your class in family Qingdao, in your class China class class grams, sold sold an student’s temperatures students of qualitative passing children of as or student’s daily of of of discrete red taken of set is Number Flavors rounded certain 1 1 10 be value. toa Practice data height) must and perform size). in in a a for members of a sporting team cafeteria cafeteria 4.1 A whole range of things 83 A stem-and-leaf can then be diagram is a visual representation of ordered raw data, which Stem-and-leaf analyzed. diagrams in Example are Japanese used train 1 timetables. Here 0, 1, are 14, the 11, Construct 0 0 0 numbers 0, an 1 6, 10, 1, ordered 1 1 4 of climate 0, 39, 1, change 13, stem-and-leaf 6 7 10 10 11 10, surveys 26, 7, diagram 4, to carried 17, 12, out 58, represent by 22, this 23 students. 15, 20, 17 data. 12 Sort 13 14 15 17 17 20 22 26 39 58 use 0 0 0 0 1 1 1 4 6 7 1 0 0 1 2 3 4 5 7 7 2 0 2 6 3 9 the data Thedata the in ascending ranges tens Construct diagram from digit a to form order. 58, the so stem. stem-and-leaf from Remember to 0 to your ordered include a data. key. 4 5 8 Key : 3 Reect ● Is ● What In a a | 9 represents and the the stem ● the leaves ● the key Practice diagram similar of to keeping a bar raw chart? Explain. data? diagram: represents the represent tells 1 advantages stem-and-leaf ● sur veys discuss stem-and-leaf are 39 you category the how nal to read gure digit(s) the of each data point values. 2 ATL 1 Here are the three-week 35, 47, 34, numbers of croissants a baker sold each day during a period: 46, 62, 41, 35, 47, 51, 59, 56, 73, 38, 41, 44, 51, 45, 60, 25, 35, 46 Use Construct an ordered stem-and-leaf diagram to represent the the number 2 The masses (in grams) of 11 Chinese striped hamsters are: the 22.4, 27.2, 30.5, 25.2, 23.1, 25.3, 21.3, 20.9, 24.5, 25.2 theleaf. Construct 8 4 a stem-and-leaf diagram 4 Representation to represent the data. part stem decimal 21.6, whole data. and part as the as S TAT I S T I C S Problem 3 The in class a 4 6 6 7 1 2 3 3 3 2 0 2 6 9 3 1 1 2 7 4 0 Write 2 | 0 least ii greatest Find the c Write d Students are 180 184 173 166 distances the class. in kilometers students 20 km travelled distance number of how who travelled. students many travel percentage the the the: down the shows school. 8 distance b Here diagram to represents down i Find 4 travel 0 Key : heights 195 of 177 students more of in than travel 18 students one-year-old 175 173 km who 13 get get apple 169 km. cheaper cheaper trees 167 in bus bus fares. fares. centimeters. 197 Use 183 161 195 177 192 161 the Reect ● What for ● ● any set single and ● data about of Measures is. data Range is sets in a stem-and-leaf the two stem. diagram. 2 arise with there central are of data as when using stem-and-leaf diagrams sets? value mode might data of the discuss problems Measures a represent and large What For and rst 166 digits Organize P R O B A B I L I T Y solving stem-and-leaf one A N D that all is are small two measure of of the central (spread) of of (location) typical measures range? categories tendency most dispersion a a summary summarize data set. The statistics: a set of mean, data with median tendency. measure how spread out a set of data dispersion. 4.1 A whole range of things 8 5 Example The 2 stem-and-leaf every day for 17 diagram days. shows Find the the number mode, median of emails and received range of this by Kirsty data. The The The 3 1 2 median is mode the is middle the value value smallest that when occurs the Key : 1 | 8 represents 18 13 a set is the 9th value, which is 20 = of 40 4 = 36 Practice The n data stem-and-leaf Wizards during Find mode, the 7 3 0 3 5 7 9 4 1 2 2 3 3 5 2 5 4 | 1 a 5 range Find day the over a mode, 7 8 2 0 2 2 5 7 7 3 0 0 0 3 6 8 4 0 1 1 5 1 | 8 9 5 shows range 9 41 diagram median 5 Key : 7 period 1 8 6 is the value the number of goals scored by the Welsh tournament. and represents stem-and-leaf every diagram netball median 2 The values, Here 3 Key : 2 in order. largest value is the median is 40. the n = 17. dierence between emails largest 1 are often. emails The Range most (04). emails value. Median 4 emails In = data is 6 The Mode value of data. goals shows range 15 the number of days. 8 represents this 9 20 and of cars 4 Representation of this data. cars parked in a car park and the smallest value. the S TAT I S T I C S Problem 3 The P R O B A B I L I T Y solving back-to-back students A N D stem-and-leaf following their diagram English and English 2 5 4 shows the Mathematics marks for a group of exams. Mathematics 2 4 0 3 0 5 1 1 6 7 1 6 3 3 3 2 0 7 5 8 3 8 4 | 0 7 9 Key : represents 40 marks 2 | 4 represents 42 marks on the Mathematics exam on the English exam 4 a Find b Write down the mode of the Mathematics c Write down the mode of the English d Find the median e Find the range f Justify The the number whether number of of students of of the the the English English English minutes who a took English Mathematics exams. marks. marks. Mathematics Mathematics sample and marks. and or the of 13 marks. marks people had are to the wait more to see consistent. a doctor in ATL her 16, oce 28, are 47, shown. 21, a Construct b Determine c Find the Reect ● What ● Which The 19, 25, 39, stem-and-leaf how mode, and many shape are easier divide median are an is of a 16, for waited range of 23 this more the back-to-back to nd extract ordered another 36, data. than 30 minutes. data. 3 easier to 12, diagram and discuss the 20, people median statistics statistics ● a does Quartiles 32, from from set of name the data for stem-and-leaf the the original diagram data stem-and-leaf values second into and show you? which diagram? quarters: quartile, Q 2 ● The lower/rst quartile (Q ) is the median of the observations to the 1 left ● of The the median upper/third in an arranged quartile (Q ) is set the of observations. median of the observations to the 3 right ● The of the median interquartile quartile and the in an range upper arranged (IQR) quartile is set the (Q 3 – of observations. dierence Q between the lower ). 1 4.1 A whole range of things 87 Example Find the data set: 2, 5, 4, The 3 median, 19, 6, 5, 8, 9, median, lower 10, 10, Q = 15, and 11, 11, 13, upper 2, 4, 15, quartiles 20, 19, 6, 13, 9, and interquartile range of this 8 20 Write the data in order. There are 12 data values, so n = 12. 9.5 2 The Q median is = 6.5th value, 2 which is the mean of 9 and 10. 9.5 2 4 5 | 6 8 9 | 10 11 13 15 Q = 19 20 The The lower quartile, lower quartile is the median 5.5 1 of the values less than Q 2 Q Q 1 2 5.5 2 4 5 | 6 9.5 8 9 | 10 11 | 13 15 19 20 The The upper quartile, = Q upper quartile is the median 14 3 of the values greater than Q 2 Q Q 1 2 5.5 2 4 5 | 6 Q 3 9.5 8 9 | Interquartile 14 10 11 | 13 range, 15 IQR 19 = 20 Q Q 3 = In Example none of the 3, the number quartiles Exploration 1 Find Q , Q 1 2 were 1 14 of 5.5 data values = 8.5 values in the n was data a and Q 4. In this case for these data sets: 3 a 2, 4, 5, 6, 8, 9, 10, 11, 13, 15, 19, 20, 22 b 2, 4, 5, 6, 8, 9, 10, 11, 13, 15, 19, 20, 22, 23 c 2, 4, 5, 6, 8, 9, 10, 11, 13, 15, 19, 20, 22, 23, n of 1 2 Summarize multiple set. your ndings in a 27 n = 13, (multiple of 4) + 1 n = 14, (multiple of 4) + 2 n = 15, (multiple of 4) + 3 table: (multiple of 4) (multiple of 4) (multiple of 4) +1 +2 +3 multiple of 4 median Q not a value 2 in original data Q and Q 1 not a value 3 in original data 3 set Determine set when Q , 1 8 8 Q 2 and Q 3 4 Representation are values in the original data set. S TAT I S T I C S Reect ● A data Will Q and set , has Q 1 ● In any the ● 650, IQR 750, the baker 34, IQR 670, Find the original of 4) data 1. set? of the lower data is less than quartile or the equal upper to: quartile? quartiles? data of tell SAT lies between the lower and upper quartiles? central tendency or a measure of dispersion? you? Mathematics 28.4, the and the 62, the (in 4 get and 31.5, to median, 0 2 8 1 0 1 2 2 1 1 3 8 3 35, median, median, the and the 750, the 730, score of 780, upper interquartile 47, and the grams) 37.2, to 720, number 41, of with 750, and ten of her friends. Their 780 lower quartiles. range. doughnuts 51, 59, the 56, upper interquartile 11 45.2, range stem-and-leaf students 420, median, range masses Find (multiple she sells each day during period: 46, b The is the percentage? her records Calculate Find called the a range a 31.6, fraction measure the three-week The of the 700, Find 47, n in were: b 35, where values 4 Calculate A what are as a does a a 4 this compared scores 3 they is the 4 the fraction Practice 2 set, What Cara be P R O B A B I L I T Y 3 data are What 1 values, Q 2 What Is n and median Why ● discuss A N D 43.1, and diagram newly 73, and 41, lower 44, 51, 45, 43 quartiles. range. hatched 33.1, 38, chicks 35.3, 41.3, are: 49.9, 44.5 IQR. shows the time taken (in minutes) by a class of school. range and interquartile range of the times. 9 4 7 3 4 5 0 Key : 1 | 0 represents 10 minutes 4.1 A whole range of things 8 9 Problem 5 The solving annual rm are salaries shown in of the a sample of 9 back-to-back senior Senior 9 8 Key : of 9 £59 | 5 represents 000 for a a and 9 employees at a law diagram. Junior 3 5 8 4 0 2 8 0 5 0 1 3 5 6 0 0 7 2 0 8 2 junior stem-and-leaf salar y 5 senior | 9 0 £50 employee represents 000 for a a salar y of junior employee a Find the median salary of a senior employee. b Find the median salary of a junior employee. c Find the range Compare of both the senior and junior salaries. medians measures 6 d Find e Compare Here 22, are 24, interquartile the 29, median The mean The upper the Write The the is is people 36, is minimum ● the lower 45, y, senior the x, y and data 47, sets of a with the upper data set (Q ) (Q ) quartile (Q ) 3 ● the maximum 9 0 junior an and junior value. 4 Representation is: 5 evening and salaries. employees. class, z median 2 ● 53, senior z value quartile median and attending 1 ● the 46.5. summary the the both 37.5. of ● of of 35. dierent ve-point 12 x, quartile values two of 30, age age range salaries ages 30, The Find 7 the IQR 7. in order: the and of the spreads. S TAT I S T I C S Exploration A N D P R O B A B I L I T Y American 2 mathematician A box-and-whisker diagram is a visual representation of the ve-point John summary. Each vertical line represents one of the ve-point Wilder Tukey summary contributed much to values. the eld He came both 10 20 30 statistics. up with box-and- whisker 0 of and stem- 40 and-leaf diagrams. Marks ATL 1 Write down 2 From the a the median b the upper 5 values information of how you can 4 Explain how you calculate 5 Determine 6 Describe The ve-point down: what the situation calculate box this the the box-and-whisker from 0 IQR diagram 30 diagram strawberry 2 4 Find the median b Find the maximum c Find the IQR masses could 10 of a Write b Calculate c Find a 1, 1, b 10, c 10 do diagram. diagram. the whiskers represent? represent. number 100 of down the of 50 18, 000, 3, range 15, 64 3, 24, 14 16 18 20 strawberries strawberries. dolphins 55 ve-point number 3, strawberries range). Amazon 45 ve-point 2, of were represented in a diagram. the the numbers strawberries. number male the 12 of 60 Mass a What represents 8 (interquartile 40 Write this this plants. 6 a box-and-whisker 3 from from represents. Number The range 5 harvested 2 summary. quartile. Explain a the write 3 Practice 1 the of and 4, 15, 000, 12 16, 75 80 (kg) summary dolphins 4, 70 of the data. IQR. summary 4, 65 for who each weigh data 52 kg or less. set: 4 21, 000, 17, 11 15, 500, 13, 11 12 750, 12 250, 10 300 4.1 A whole range of things 91 4 Construct property a box-and-whisker items found Minimum on Q a diagram for Median Q 1 15 5 The of data on the number of lost Maximum 3 22 number this train. 33 minutes that 37 10 people 41 wait to be connected to a helpline are recorded. 5, 6 8, 13, 19, 22, Find the median b Find the lower c Construct The heights, 30.1, Construct The a a in 8 8 9 4 0 3 4 4 5 3 7 8 8 6 1 | 7 8 32.4, of diagram down b Find the median c Find the interquartile d Construct median 28.5, data. are: 32.0, diagram shows the the 34.6, for 39.1, the 28.9, 34.4, 24.7 data. number of diners at a restaurant the 38 diners minimum number number of of diners. diners. range. box-and-whisker diagram for the data. solving a 32, trees for 8 Write Construct diagram period. a Problem 12 20.0, represents a 34 quartiles. box-and-whisker 3 3 upper meters, two-week Key : 30, box-and-whisker 36.5, a 27, time. and stem-and-leaf during 8 22, a 29.2, 7 20, box-and-whisker minimum 18, Q diagram 23, IQR for 12, a data range set C A, B, C, D and E in the Describing stem-and-leaf 21, and ● How do measures ● How do dierent 9 2 of diagram and nd the dispersion help representations 4 Representation you help 9 2 B 6 8 3 C 3 4 values here. comparing A with: 1 of 1 sets of describe you data data? compare data sets? D 8 E S TAT I S T I C S Exploration A doctor simple soon in is they seconds In one saw (to 2 a how task, red d.p.). lack Here come are 0.58, 0.53, 0.58, 0.43, 0.58 Set 2: 0.66, 0.10, 0.58, 0.58, 0.78 2 The had the people been which is Reect In mean, were for You and could Why ● The the two could the Distributions clear peaks Example The for sets use for 24 spent Describe b Compare 0 a typical Set this the of data set of from the Explain set the press is do button as measured for each the other ‘fully reasons to task: For for a were range readings. which to times interquartile Decide one clear reaction value? same in compare Set the peak for set. set, rested’ your they and decision. time What for Set does 1 this was 0.58 single seconds. value tell you mean. 1 and two are How in data called Set well 2? does What the mean other measure sets? unimodal. Distributions with two bimodal. stem-and-leaf the study the study diagram Mathematics times times of of the girls the girls 0 0 0 5 0 0 1 0 0 0 5 5 0 0 2 0 0 0 0 0 0 0 3 0 0 0 0 0 0 0 4 0 0 5 0 0 5 0 0 0 6 0 5 0 7 5 a | 2 | boy 0 in shows one and how week. much All time times are a group in of minutes. boys. and boys. Boys 8 and one instructed response ability 1? have studying 0 Key : and person’s 5 Girls 5 The a 4 a 5 were sets hours’. situation to called back-to-back students for hours. choose real with are that we times you rested 24 discuss say data describe median, aects 3: would about fully for ‘awake Exploration ● mode, awake sleep on. two 1: Find of participants light Set 1 P R O B A B I L I T Y 3 investigating tasks. as A N D 0 0 0 0 0 5 5 5 represents studying 0 for a girl 20 studying for 25 minutes minutes Continued on next page 4.1 A whole range of things 9 3 25 + a The median is the = 13th value. n = 25 for the girls and for the boys. 2 The median time for the girls The median time for the boys For the = Q is 35 is minutes. 20 minutes. girls: 25 minutes, Q 1 = 50 minutes 3 Use The interquartile range = 50 25 = 25 the to describe each For the = Q set of the and 20 minutes, interquartile Both the About Q = 35 girls The distributions 30 median for of the time for 35 only boys more or = than girls 15 one spent more the On 20 minutes mode 25 (unimodal). minutes two-thirds or of less Use the the stem-and-leaf describe the shape greater than the is average, boys’ IQR, so longer the girls than the spent of the Objective: move C. stem-and-leaf you has dierent will diagrams, between Practice times a the larger be changing and dierent forms to forms the of spread. mathematical the representation representation of the diagrams. data These from are tables to examples of representation. 6 ATL The by back-to-back some boys stem-and-leaf and Girls 8 girls to diagram complete a shows simple the 9 1 7 5 5 4 2 2 3 5 7 7 7 9 8 8 5 1 0 3 1 2 3 4 4 7 9 6 4 3 4 5 5 6 9 7 2 5 1 2 2 1 6 9 9 8 Key: 3 | 4 | 5 represents a girl who took 43 seconds and a boy who took 45seconds 9 4 4 Representation times jigsaw. Boys 9 measure and of central the measure the girls of middle box-and-whisker of distribution. median Communicating between practice moving girls’ each to more dispersion 50% of diagram studying. tendency 1 of data. Compare this range spread minutes have minutes boys. = the Mathematics; spent time range two-thirds studying In and 3 The iii. interquartile center boys: 1 b median minutes taken (in seconds) for and boys. S TAT I S T I C S a Calculate the b Describe c Compare the The shape the Problem 2 median and of times interquartile the taken range of times for the girls and A N D boys. distributions. by the girls and the boys. solving average monthly temperatures recorded over a year in the US cities of On Sante Fe, New Mexico, and Saint Paul, Minnesota, are given below. the temperatures are in the zero data in a back-to-back stem-and-leaf temperature diagram. produced b c Describe the Compare temperatures the represents Fahrenheit. the Represent Fahrenheit All scale, a P R O B A B I L I T Y in the two by mixing equal weights snow and of cities. common temperatures. salt. Sante Saint 3 The Paul heights Apple Pear 4 Fe (in F M A M J J A S O N D 44 48 56 65 74 83 86 83 78 67 53 43 26 31 43 58 71 80 85 82 73 59 42 29 centimeters) trees: trees: a Represent b Describe c Compare The J the the one-year-old apple and pear trees 180, 184, 195, 177, 175, 173, 169, 167, 197, 173, 166, 183, 161, 195, 177, 192, 161, 166 171, 160, 182, 168, 194, 177, 192, 160, 165, 178, 183, 190, 172, 174, 170, 165, 166, 193 data in heights the of a of back-to-back the apple stem-and-leaf and pear are shown below. diagram. trees. heights. box-and-whisker diagrams show the delayed departure of two trains, A and B. Train A Train B 0 10 20 Length Compare 5 The ages the of a lengths of the sample of subscribers Süddeutsche Zeitung: of 30 delay 40 50 (minutes) delays. to two German newspapers are 65, 36, 44, 25, 37, 29, 27, 19, 60, 46, 35, 20, 55, 64, 30, 31, 22, 48, 53, 67 shown below. 24, Use Der Tagesspiegel: 46, 18, 35, 20, 27, 25, 40, 24, 31, 18, 30, 19, 28, 21, 34, 54, 22, 27 29, 20, 63, and the same draw Construct two box-and-whisker diagrams for the two data one box-and-whisker diagram a scale, above the sets. other. b Compare the ages. 4.1 A whole range of things 9 5 6 Patricia shows 1 1 5 9 2 0 4 8 3 4 7 4 7 5 0 Ray work in a monthly mobile sales for phone the 3 | 0 4 represents 34 mobile diagram 10 phones shows 20 Ray’s Compare Patricia’s The Should ● How outlier of is a the IQR and Ray’s eect ● pattern 1.5× stem-and-leaf we do of 40 below of Q of the , or of phones Exploration foot given 20, 1 lengths the same 50 year. 60 70 sold results a that stand data data. A greater aren’t out set a which data than in point 1.5 × typical? crowd? does not is outlier an IQR t above with if it the is general less than Q 3 4 (measured to the nearest centimeter) of 19 students are below. 23, 22, 17, 24, a Find the lower b Find 1.5 × c Use can 2 for outliers ignore member sales sales. individuals rest monthly 1 The diagram sold 30 Number An The year. 8 box-and-whisker D store. previous 7 Key : The and Patricia’s Find the be the length mean, excluding your 9 6 interquartile of an 23, 46, upper range 18, 26, 25, quartile 21, and 24, 26, 30, interquartile 24, 20 range. (IQR). outlier to determine if any of the data median, any an mode, range and interquartile range of the the outliers outlier. results in statistics a points outliers. data: b of 24, quartile, denition including Which 27, considered a Record 27, table. are aected 4 Representation by the outlier? Justify this result. foot S TAT I S T I C S Reect In and Exploration discuss What ● When the which measure might What When a are set of data result occurred data has then decide speaking, it can any be a the identify (2) use (3) Practice group them 8, to 2 and of 17 23, b Determine the of the one the or not spread. a outlier. If to you use measuring If it is a them think a device, genuine it. indication just whether and misreading keep and distribution? of the extreme dispersion value. You of a may set of need to range. tendency (center) and a measure of and shape. young set. 22, a range children set of 25, are not of text 16, it 19, 48, mean b Find the interquartile c Determine d Find the excluded and any range. in is and of 30, tested 62, 31, mode better for to your sent 27, median aected by outliers. to see how bricks. long Their it took times (in each of seconds) 31, of use 32, the the 32, 40, 48, 51 times. mean, median or mode for this answer. by 22, 17 34, number adults 31, of 36, texts in one 28, week 30, 12, are shown below. 20 sent. range. the Give your measure 28, messages the if 27, reasons Find Which were interconnecting median whether Give 8, 25, a e decide ignore to good by central interquartile mean, number 40, a calculating (spread) the 24, Find 36, is can not the here. a The or tendency outliers? tendency error, central describe outliers measure assemble 16, data you to of to 7 shown 12, need (typing use ignoring central aected before any describe median range of measure you distribution: (1) a you of whether greatly outliers describe are outliers, device) then which would results measures dispersion A included, potential the outliers? dispersion measuring exclude 1 any error but The for human Generally To 6 by point, data, is of some calculating broken account outlier when P R O B A B I L I T Y 4: ● ● A N D a data values reason why can any be considered outliers have outliers. been included or calculation. of central tendency is more appropriate in this case? Explain. 4.1 A whole range of things 97 3 Look back at a Determine b Find any the The if data any range outliers Problem 4 the of 30 Male 8 8 Mathematics the data study been values times for included study can the or times be girls in Example considered and excluded boys. in outliers. Give your 4. a reason why calculations. solving back-to-back nearestkg) of of have on stem-and-leaf male and 30 diagram female wombat Female 0 8 shows northern the masses hairy-nosed (to the wombats. wombat 9 8 5 2 0 1 0 5 7 8 9 8 8 7 7 1 0 0 0 2 0 0 0 0 5 7 8 8 7 5 2 2 2 1 1 0 3 0 0 1 1 1 2 5 5 4 3 2 2 0 4 2 2 3 4 0 5 0 6 8 8 6 7 8 9 0 Key : and 5 0 a | 4 Decide b Describe c Compare 26 table 2 represents female a The | wombat whether the the of there masses masses shows cantons 10 the a male with are of of mass any the the wombat mass 40 kg kg outliers. male and male percentage 42 with of and female wombats. female households wombats. that speak English in the Switzerland Switzerland. ocial a Construct a stem-and-leaf diagram and determine whether there outliers. are any From 2010 Swiss Federal Statistical b Suggest how any outliers could have Describe the the Oce allowed citizens distribution. to indicate than ZH BE LU UR SZ OW NW GL ZG 6.4 3.0 2.9 1.6 3.8 2.8 2.6 1.2 8.4 as SO BS BL SH AR AI SG GR AG 2.5 8.6 4.2 3.6 2.1 2.4 2.5 2.5 3.5 TI VD VS NE GE JU FR TG 3.1 7.4 2.6 3.3 10.7 1.5 2.5 2.4 one their for all 4 Representation more language main language so the total languages exceeds 9 8 four occurred. has c has languages. 100%. S TAT I S T I C S A N D P R O B A B I L I T Y Summary ● In a stem-and-leaf the stem the leaves ● diagram: represents the represent category the nal A ve-point gure digit(s) of each summary the minimum the lower data quartile of a data point (Q set is: (min) ) 1 data point the median (Q ) 2 the key tells you how to read the values. the upper quartile (Q ) 3 stem leaf 0 0 the 0 0 1 1 1 4 6 0 0 1 2 0 2 6 3 9 2 3 4 5 data point (max). 7 ● 1 maximum 7 A box-and-whisker ve-point 7 diagram represents the summary: Whisker Box Whisker Median, Q 2 Lower Upper Minimum Key : 1 | 0 represents Maximum Quartile, Q 10 Quartile, Q 1 ● ● For any set summary of data there are two categories Qualitative ● of central tendency where question Quantitative data most data lies. They ‘What is an average data two a certain (color, animal). of dispersion spread out the between the ‘How (spread) data is. much data has data They scored) is ) is value. a numerical value. There – can or be can counted only take (number certain of values size) there (weight, (Q numerical answer variation Continuous quartile a describe values?’ lower/rst has value?’ (shoe question – types: goals The words answer Discrete Measures ● describes using (location) are the – characteristic Quantitative describe how data of statistics: Measures the 3 the median data height) – can and be can measured take any value. of 1 the observations arranged ● The set of to the left of the median in an ● observations. upper/third an ● observations quartile arranged The set to of interquartile between quartile the (Q (Q 3 right ) of is the the median median of ● in range (IQR) quartile and is the the An of outlier does observations. lower – Q the distribution behavior 3 the The not of the or an all is t a It a data data the could inaccurate set of the general be describes points member with data. of the an in the data set pattern anomaly the set. of in which the the rest data reading. dierence upper ● ). A data 1.5 1 × point IQR is an below outlier Q , or if it is greater less than than 1.5 × 1 above ● The median quartile, is another name for the second Q 3 Q 2 Mixed 1 Write practice down quantitative whether these are qualitative data. a The color of b The prices c The areas d The numbers of graphic public of 2 Write down continuous owers of or calculators parks people at a store whether these are discrete or data. a The time taken b The number c The heights d The temperature of of to run a marathon carriages on Humboldt at a train penguins midday 4.1 A whole range of things in Iceland 9 9 IQR 3 The masses are given 46, 52, (in kilograms) of a group of people Problem solving below. 8 The box-and-whisker diagrams show the ages of ATL 64, 60, 82, 48, 72, 61, 70, 75, 59 people a Construct a stem-and-leaf diagram watching two dierent lms at a cinema. to F ilm A represent the data. F ilm b Write down the number of people B who 0 weigh less than 60 10 20 30 40 Age 4 c Find the median d Find the range. During a one-hour students study break, the amount spent Their a Compare b Deduce on social media sites times, in minutes, 45, 37, 29, 48, 52, 41, 32, 26, Calculate the median b Find the interquartile c Find the range. Problem which Give Sebastian The 50, 32, shoes prots 11 made years time. 000, $170 are $38 range. $560 000, $62 5, 6, 7, owned 7, are 9, 9, by in r, calculated was 9.5 by as as a family answer. a small business during the follows: 000, $1000, 000, $250 a Find b Determine data on the number of $85 000, 000, $160 $3100, 000, $120 000, the interquartile if any of range. the data values can be every student in his and Find the range. Give a reason why any class. have been included or excluded in order. 10, that the outliers. pairs s, 13, 13, the upper your calculation. Find the t d He your solving collected values categorized 000 outliers The is for 44 c of lm reasons considered 5 ages. were: $45 a the was last 20, 70 of 9 recorded. 60 (years) mass. lm. time 50 kg. median of the quartile Q data was set is 13. most measure of appropriate central in this tendency case. which Justify your choice. 3 a Write b The down the value of r and s Problem mean of the data set is 10 Find the value of The table shows All the dogs the masses (in kilograms) of t ATL Blackface 6 solving 10. attending a veterinary surgery sheep on two farms. were ATL weighed. Their 26, 18, 54, 90, 16, 5, 32, 27, a Find a b Construct masses, 30, 18, 25, 3, ve-point in 6, 23, kilograms, 32, were: Farm A 63 48 60 55 45 49 19 55 Farm B 54 71 68 57 62 70 54 49 Farm A 65 49 57 56 64 43 64 48 Farm B 66 68 72 50 56 49 70 64 43, 27 summary for the data. a a box-and-whisker diagram Construct a back-to-back stem-and-leaf for diagram to represent the data. thedata. b 7 This box-and-whisker diagram represents Compare on results you from when a survey you got that your asked: rst ‘How the old the two c smartphone?’ The table grazing a 18 30 Age The interquartile is Write b Find c 160 down the the values 20 median of a Poor and the range is 40. shows of were the average Blackface people 10 0 who and hill Deduce b surveyed. were adult sheep for dierent hill 30 45–50 kg 50–65 kg 70 kg value. Find the or older. 4 Representation the sheep grazing on number your of sheep conditions. Average/good the people Blackface farms. Upland a the b (years) range of were bodyweight 4 masses the answer. the conditions two farms. available Give to reasons for S TAT I S T I C S Review in A N D P R O B A B I L I T Y context Globalization and sustainability 1 The by table forest shows in 19 the percentage European of Union Austria 46.7% Belgium 22.0% Czech 34.3% land states 2 covered in The box-and-whisker coverage 2010. 0 Republic Denmark 11.8% Estonia 53.9% Finland 73.9% France 28.3% Germany 31.7% Greece 29.1% Hungar y 21.5% for 10 20 33.9% Lithuania 33.5% Netherlands 10.8% Poland 30.0% Por tugal 41.3% identify the any 3 Use the data Slovakia 40.1% Sweden 66.9% more Kingdom 11.8% Construct a box-and-whisker diagram for 40 50 for 2010 in the forest 2012. 60 70 80 (%) and between forestry data. representation to present can to the 2012 the and two years. if Nations website an nd appropriate prepare classmates, between Economic to a short and dierent form report show forms how of to Explain the conclusions you data. draw Determine Use and your move representation. represent (United Europe) of you b states coverage changes UNECE Commission a 30 EU shows 9.7% Italy United same Forest Compare Ireland the diagram there are any outliers in from your diagram. this data. Reect and How you have discuss explored the statement of inquiry? Give specic examples. Statement of Inquiry: How and quantities trends in a are represented can help to establish underlying relationships population. 4.1 A whole range of things 101 can Getting your ducks in a row 4.2 Global context: Objectives ● Finding from ● a the frequency SPIHSNOITA LER ● mean, Finding median, frequency grouped mode and data in ● range F table a ● cumulative the frequency summary from a ● C curve Constructing a a frequency cumulative How can you How box-and-whisker diagram How it can can you does be nd from cumulative ve-point and sustainability questions tendency curve cumulative ● Inquiry grouped Representing Globalization a the represent frequency the measures grouped type of represented of central frequency grouped table? data in data and aect the way analyzed? from curve ● How can ● How do real data ever be misleading? D individuals stand out in a crowd? ATL Communication Organize and depict information logically 4.1 Statement of Inquiry: How and quantities trends in a are represented can help to establish underlying relationships population. 4.2 6.2 10 2 a curve? S TAT I S T I C S Y ou ● should understand already inequality know how notation 1 Which a recognize discrete continuous ● calculate the frequency and 2 of 4.2 Is data these write a each construct a data mean from a 3 Numbers b Heights c Shoe d Lap The data summar y and 4 a of quar tiles divide a 5 c How can When into you How have groups can a before with you frequency ● c 6.4 d discrete 6.0 or nd measures laid sunower in a table children the in 6 hens plants mean 1 shows a car race the playgroup. age. 1 2 3 4 5 Freq 0 2 6 4 3 a a for Scout box-and-whisker this data 13, 13, 13, 14, 17, 18, 18, 20, 21 Find any data is the less the ages 15, interquar tile set, what than lower the the the on group. 12, of by Formula 15, grouped the eggs Age Write Working of times of data b ● the 6? 11, In a F satisfy sizes diagram set of Construct box-and-whisker how ≤ set frequency ages b identify x 3.0 a diagram ● < values continuous? table ve -point 3 b Calculate ● P R O B A B I L I T Y to: inequality ● A N D or range. fraction equal of the to: quar tile median upper each quar tile? fraction as a percentage. data central tendency from a grouped table? you large represent set doing of any data grouped it is statistical data often in a cumulative convenient to frequency organize the curve? data analysis. 4.2 Getting your ducks in a row 10 3 ATL Example The 1 lengths of 50 Eelgrass leaves were measured. The results are given Measuring below, to 46.3 the nearest 35.6 tenth 75.2 of a 43.7 52.7 57.3 49.0 57.3 leaf 42.6 47.1 50.3 50.7 gives continuous data; this 34.2 58.0 37.0 59.3 has to 55.6 be 56.0 a centimeter. 68.1 rounded to a 59.9 certain 53.6 34.0 74.4 70.9 44.2 41.3 64.9 39.3 44.2 68.3 54.2 40.7 76.8 38.2 70.3 33.5 64.3 64.6 68.7 69.9 degree accuracy used in to of be statistical analysis. 48.9 51.6 51.7 a Construct b Find c Write a minimum the range a grouped class down = 46.0 = that modal 33.5 76.8 frequency interval the cm, 33.5 52.0 = 45.6 table contains to the 64.1 63.4 represent the 45.1 62.0 data. median. class. maximum 43.3 = 76.8 cm cm Choose = 4.33 so use a class width of 5 15 Length, x (cm) Freq a class width to give between 5 and cm Cumulative Write equal the class width classes. intervals (In using this case, inequality 10.) notation. frequency 30 < x ≤ 35 3 3 35 < x ≤ 40 4 7 40 < x ≤ 45 6 13 45 < x ≤ 50 7 20 50 < x ≤ 55 < x ≤ 60 7 35 60 < x ≤ 65 6 41 65 < x ≤ 70 4 45 Add a Cumulative frequency column to help nd the class interval that contains the median. The of cumulative the and including cumulative 70 < x ≤ 75 3 48 75 < x ≤ 80 2 50 The b n = 50, so the The class The modal median interval that is the = contains the 25.5th median is data 50 < x 25th and class is 50 < x ≤ ≤ current frequency 26th is every is values 3 the one. + are 4 in up Here, + 6 = this modal class is the class to the 13 class. interval 55. 4 Representation sum class, 55. with 10 4 the for value. The c frequency frequencies the highest frequency. S TAT I S T I C S Reect ● What ● Why and does can’t frequency ● How The cumulative you class you the 1 frequency the exact estimate range width minimum nd P R O B A B I L I T Y represent? value of the range from median from a grouped table? would Estimate discuss A N D is of the possible the lengths of dierence values in a a Eelgrass between class grouped frequency table? leaves. the maximum and the The interval. has class class because An of estimate highest When the the most For for the range class interval) class widths data. grouped It has data, a (lower are the you from – equal, highest can nd grouped bound the frequency of lowest modal class table class is the is (upper interval Practice 1 The table th shows the heights x (cm) of < x ≤ 1.30 4 1.30 < x ≤ 1.40 6 1.40 < x ≤ 1.50 8 1.50 < x ≤ 1.60 6 1.60 < x ≤ 1.70 6 Write b Find Here down the are 18 = the class the modal interval class containing class interval that contains the median. value. data modal class of mode one has a group of students on their 14th times taken for contains some the to the nearest whole value. birthdays. median. students to complete a 1500 m race second). 325 580 534 500 532 328 600 625 450 435 450 340 357 370 401 456 388 626 532 399 a Construct a equal and size b Find the c Determine grouped rst modal frequency class table interval 300 for < x this ≤ data. Use class widths of 350. class. which class interval contains the median value. 4.2 Getting your ducks in a row a instead ATL (measured 2. bound class. that 20 interval). Frequency 1.20 a ≤ 2, frequency. the the x 1 Height, 2 contains < 20 Grouped class 18 width 10 5 3 The heights of one-year-old apple trees are shown below, measured to the ATL nearest cm. 180 184 195 177 175 173 169 167 197 173 166 183 161 195 177 192 161 166 a Construct a b Write c Determine down Problem 4 The grouped table the which shows w contains the median weights (g) of apples picked Frequency from Cumulative 40 < w ≤ 50 7 12 50 < w ≤ 60 5 b 60 < w ≤ 70 c 19 70 < w ≤ 80 8 d 80 < w ≤ 90 3 30 the that values the back at you Assume the mean Now the all class the What to the the in d the class 50 < w ≤ 60. data in For all the 30. of data aect be data estimate midpoint class interval in the assumption, or and of in For each leaves has class the 30 < x calculate class example, this estimates. all upper Eelgrass in Example an value ≤ 35 of the assume estimate in interval the assumption, has class the for 30 < x calculate an value all the ≤ 35 of assume estimate for the better of in a the How each would estimate than the class mean class class of choosing the upper a dierent 4 Representation value mean? or lower class boundaries interval? from mid-interval lower The of a value grouped of each boundaries interval to frequency class and interval dividing calculate table: the by by 2. mean. on next page lower the (not Continued 10 6 1. leaves. would midpoint for data. example, Using the two the table raw each this boundary. are the leaves. interval an the and frequency Using the that your value adding Use of length represent Find c received the 35. class class calculate not boundary. are values mean b, lies grouped all assume Compare of the that lower a, 1 length the the median had values of tree. frequency 5 upper value. one a Imagine ● interval 40 Look ● class the Exploration To class. ≤ Verify d data. w b c this < Calculate b for 30 a a modal table solving Weight, 1 frequency boundary interval 31 or is 30.1, 30 etc.). S TAT I S T I C S 2 To calculate for mid-interval Length, x an estimate value (cm) of and the a mean column for for Frequency the Eelgrass mid-interval leaves, value add × Mid-inter val a A N D P R O B A B I L I T Y column frequency. Mid-inter val value value × frequency 30 < x ≤ 35 3 32.5 32.5 × 3 = 97.5 35 < x ≤ 40 4 37.5 37.5 × 4 = 150 40 < x ≤ 45 6 42.5 45 < x ≤ 50 7 47.5 50 < x ≤ 55 8 52.5 55 < x ≤ 60 7 57.5 60 < x ≤ 65 6 62.5 65 < x ≤ 70 4 67.5 70 < x ≤ 75 3 72.5 75 < x ≤ 80 2 77.5 Total frequency (number Sum of of inter val obser vations) mid- value × frequency For For grouped data the mean is dened individual points as: data in the dened Copy You can and also complete calculate the an table, and estimate of calculate the mean an estimate using a for the a set of mean is as: mean. GDC. RAD 1.1 A B C D 1 Enter the mid-interval values and 2 32.5 3 frequencies into your GDC. 3 37.5 4 42.5 6 47.5 7 4 5 B1 B11 RAD 1.1 A B C D 2 37.5 4 42.5 6 47.5 7 Σx 52.5 8 sx 3 x 53.5 Σx is 2675. the mean. 2 4 150063. 5 : = Sn … 11.9095 6 σx D2 = : = σn … 11.7898 53.5 4.2 Getting your ducks in a row 10 7 Reect ● In and discuss Exploration the Eelgrass 1, what leaves? 2 does What the does mid-interval the value mid-interval × represent for frequency value represent? ● Why can you frequency ● original data Use raw the Eelgrass the 1 The data from shows videos Time, the only an estimate estimate for the for the mean mean likely from to be a grouped one of the in Example Compare 1 the Exploration to calculate calculated the mean mean with length your of the estimate for 1. 2 table online Is values? leaves. mean Practice calculate table? t in the number one (hours) of hours a group of 50 students spent watching week. Frequency Mid-inter val value Mid-inter val value × To nd the mid- frequency interval the 0 < t ≤ 10 8 5 upper < t ≤ 20 12 20 < t ≤ 30 16 30 < t ≤ 40 11 40 < t ≤ 50 3 and Total a Copy and b Calculate online 2 The complete an the estimate table. for the mean each student spent watching videos. weights of Weight, w the Irish Wolfhounds (kg) < w ≤ 48 2 48 < w ≤ 51 5 51 < w ≤ 54 12 54 < w ≤ 57 13 57 < w ≤ 60 8 a Calculate an b Write c Find d Determine down the estimate the for modal number the at a dog show are shown Frequency 45 10 8 time of class the mean weight of the dogs. class. dogs who interval weighed that 4 Representation 54 contains and add lower 40 class 10 value, kg the or less. median. in the table. boundaries divide by 2. S TAT I S T I C S Problem 3 The table P R O B A B I L I T Y solving below Weight, A N D w shows (kg) the weights Frequency (w) of sh caught one morning. (f ) Many scale 0.6 < w ≤ 0.8 types can be of used 16 to 0.8 < w ≤ 1.0 35 1.0 < w ≤ 1.2 44 1.2 < w ≤ 1.4 23 weigh only sh some but are recognized by International Fish < w ≤ 1.6 scale between Estimate, correct to the nearest 0.1 kg, the mean weight of the Find the modal Any sh class. caught that round weighs no more than 1.0 kg must be two angler marks returned to to the known the weight. sea. Find d Find the e Estimate f A sh Cumulative You For the ● on can a set nd n estimate the range doing of 1.2 any stay x-axis, that the kg returned. contains the median. weights. was incorrectly recorded explain in whether the or class not the 1.0 ≤ w mean < 1.2. and same. curves curve and the ve-point data sh calculations, the frequency the of interval frequency the of the will cumulative plotted number weighing median A the class Without values is a graph cumulative summary on a with the upper frequencies from cumulative a on cumulative frequency class the boundaries y-axis. frequency curve, to curve. nd for: lower quartile Q , nd the value on the x-axis which corresponds to 1 25% ● the of n median Q , nd the value on the x-axis which corresponds to 50% of n 2 ● the upper quartile Q , nd the value on the x-axis which corresponds to 3 75% of If is must down heaviest c reading sh. the b for records. 10 the a Game Association potential 1.4 the n 4.2 Getting your ducks in a row 10 9 The the cumulative Eelgrass frequency data in curve Example here represents the grouped frequency table of 1. y Upper quartile, Q 3 50 45 75% of 37.5 on to the 50 = the 37.5th value. Draw cumulative cur ve, then a frequency down to the line axis x-axis from across and 40 ycneuqerf read 37.5 off the value. Q = 62 cm 3 35 Median, Q 2 30 evitalumuC 50% of 50 = 25th value. Q = 53 cm 2 25 Lower quartile, Q 1 20 25% of 50 = 12.5th value. Q = 44.5 cm 1 15 12.5 10 Q Med Q 1 3 5 0 30 40 35 45 50 Leaf 0 30 35 40 45 55 60 length 50 Leaf 65 70 75 (cm) 55 60 length 65 70 75 and can use take it to ● Why Q , ve-point the and the and Find ● Do How the box-and-whisker percentiles the cumulative diagram at the frequency same curve scale. 3 25%, 50% and 75% used to nd estimates for respectively? ve-point values the raw could number than from 3 the from summary discuss Q 2 ● ● the are Q 1 Maximum draw Reect 80 (cm) Minimum You x 80 62 of from data you Or the in use leaves cm? summary from cumulative Example the with 1? the between 50 less and Eelgrass frequency Which cumulative lengths raw frequency than 62 curve values or are data agree the curve equal to Example with most to 62 in the values accurate? estimate cm? 1. Or the greater cm? y Practice 1 The the in Find the university estimate of an of the curve league. for the median players. estimate for the upper The 90 lower Find an 70 Association for measured while 2.31 the range. 1.6 1.7 1.8 1.9 2.0 Height 4 Representation the meters tallest 40 0 110 1.6 50 10 interquartile history 60 quartiles. estimate National Basketball 20 c in 80 30 and shortest player basketball evitalumuC Find a an height frequency heights ycneuqerf players b 100 cumulative shows a 3 2.1 (m) 2.2 2.3 x meters. was S TAT I S T I C S 2 The table shows the distances walked (in kilometers) by members of A N D P R O B A B I L I T Y a ATL walking group Distance, d in one week. (km) Frequency Cumulative frequency 0 < d ≤ 3 4 4 3 < d ≤ 6 14 18 6 < d ≤ 9 6 12 8 9 < 12 d < ≤ d ≤ a Copy and b Construct 15 4 complete the table. Plot a cumulative frequency curve to represent this data. (3, and c Find estimates for the median and the 4), join 3 Find The estimates table shows for the the range masses of and the 18) with etc. a quartiles. smooth d points (6, interquartile Great Danes curve. range. at a rehoming shelter. ATL Mass, m (kg) 65 < m Frequency 70 70 < 7 a Construct b Write c Construct a ≤ a Problem ≤ 75 75 < m 13 cumulative ve-point a m for box-and-whisker 80 80 < 9 frequency summary ≤ curve the to m ≤ 85 85 < m 12 represent this ≤ 90 9 data. data. diagram. solving ATL 4 For the sh in Practice 2, Q3: a Construct a cumulative b Construct a box-and-whisker c Use are d your true cumulative or frequency sh weigh 1.1 ii 60 sh weigh between of The table curve to decide whether these statements false. 90 25% curve. diagram. frequency i the quartile, 5 data sh nd are the shows kg or less. 1.1 classed as minimum the masses kg and kg. overweight. weight (in 1.5 at grams) By which of using a sh apples in 50 ≤ the is a calculated classed as upper overweight. box. ATL Mass, m (kg) 30 < m Frequency a Construct b Apples Find c 10% of 40 40 < m 5 a estimate the less for apples ≤ 50 < m 7 cumulative weighing an ≤ the weigh 45 g more curve cannot number 60 < m 5 frequency than 60 of than for be 70 2 this 70 < m ≤ 80 80 < 8 m ≤ 90 3 data. sold. apples x ≤ that grams. cannot Find be sold. x 4.2 Getting your ducks in a row 111 6 This box-and-whisker diagram shows the times taken by 100 people to ATL complete the a simple word puzzle. Construct a cumulative frequency curve for data. 0 5 10 15 20 T ime Problem 25 30 35 40 (seconds) solving ATL 7 The cumulative hour) of some frequency cars on curve here motorway shows the speeds (in kilometers per A. y Only 140 ycneuqerf on three the countries world the motorway evitalumuC limit in hour rather miles 60 kilometers 40 0 90 100 110 Speed b The estimate speed Find c an an a for on estimate Construct The limit the the for median the 70 speeds Grouping C ● of below 80 90 100 Speed Compare 130 diagram diagram 130 140 x km/h. cars for exceeding the shows speed the the data speeds speed for of limit. motorway some cars A. on B. 60 d is percentage box-and-whisker 120 (km/h) speed. motorway the box-and-whisker motorway How does of the cars on discrete the type of data 110 120 130 140 (km/h) motorway A and motorway B. data aect the way it can be represented and analyzed? When data is you represent discrete 1 12 or per 80 the Great the United and Find speed 100 than per data in a continuous, frequency as this 4 Representation table, aects you how rst you need write to the decide class if the intervals. hour: Britain, States 20 a give 120 Burma. S TAT I S T I C S Continuous boundar y continuous and one When the ≤, you mean For data has values inter vals, for written with one Discrete with < data boundar y sign between has values the inequalities no class are ≤, there for ≤ 40 35 ≤ x ≤ 40 40 < x ≤ 45 41 ≤ x ≤ 45 continuous on way data, for frequencies the as class for intervals, grouped example against 35 the < you can continuous x ≤ upper 40, 40 class gaps Both example: x decided are inter vals. < same calculate an estimate of data. < x ≤ 45, plot boundaries 40 the and All 45. values round and For discrete data, for example 35 ≤ x ≤ 40, 41 ≤ x P R O B A B I L I T Y overlapping and 35 the cumulative is example: have in overlapping and A N D ≤ 45, plot the all interval against (40) Example and the next point lower halfway bound between (41), at the upper bound 40.5 to values 40, ≥ 40.5 cumulative round frequencies < down of up to 41. one 40.5. 2 ATL Dieter recorded intervals 3 over 14 a the number period 6 of 3 of trucks hours. driving His results past are his house shown 16 21 6 20 14 in 5-minute below. 4 11 12 19 1 12 19 14 11 16 24 20 6 18 8 27 7 23 2 7 11 12 11 7 27 24 12 22 15 29 9 25 14 10 10 16 15 19 1 17 8 12 Construct a Number cumulative of Freq frequency curve New for upper this data. Cumulative Find trucks boundar y for 1 ≤ x ≤ 5 5 = 5.5 the new each halfway class x ≤ 10 11 11 ≤ x ≤ 15 15 = 10.5 = 15.5 of class x ≤ 20 10 21 ≤ x ≤ 25 6 26 ≤ x ≤ 30 3 = 20.5 = 25.5 = 30.5 one the interval boundary value class of and the the next. 31 a Cumulative column ≤ – upper 16 Add 16 the 5 lower ≤ boundary interval between boundary 6 upper frequency to the frequency table. 41 47 50 Continued on next page 4.2 Getting your ducks in a row 1 13 y 60 ycneuqerf 50 Plot 40 upper boundary evitalumuC cumulative the y-axis. The 20 10 5 10 15 20 Number You can discrete obtain data Practice a State and b The a 30 x 35 trucks ve-point exactly whether give the the 10 < x ≤ 20 20 < x ≤ 30 table these reasons down here Number a in of 25 summary same of class for class width ii shows words the x ≤ 18 19 ≤ x ≤ 23 number 17 5 ≤ x ≤ 9 25 10 ≤ x ≤ 14 30 15 ≤ x ≤ 19 12 20 ≤ x ≤ 24 10 25 ≤ x ≤ 29 3 30 ≤ x ≤ 34 2 35 ≤ x ≤ 39 0 40 ≤ x ≤ 44 1 114 an your Write box-and-whisker diagram for data. the estimate answer class down for make interval the continuous or discrete data, of interval. iii words in 6 < x ≤ 9 9 < x ≤ 12 each of 100 iv sentences 20 – 39 40 – 64 in abook. Frequency 4 c a continuous represent each ≤ ≤ Calculate of 14 x Find draw for answers. ≤ b and as intervals your 0 Does way 4 Write i 2 new and on frequency the on 30 0 1 the x-axis the sense that modal mean in number the contains class. 4 Representation of context the words of this median. in each sentence. question? rst point is (5.5, 5). S TAT I S T I C S 3 Beatrice of the records 25 Number goals the matches of 0 number in ≤ x goals scored by her unihockey team for each season. 3 4 ≤ x 3 a Calculate b Explain c Find d Estimate The ≤ of P R O B A B I L I T Y ≤ 7 8 ≤ x ≤ 11 12 ≤ x ≤ 15 16 ≤ x ≤ 19 scored Frequency 4 the A N D estimate why the table an this class the 5 for data interval is the 6 mean number 6 of goals 5 scored per match. bimodal. that contains the median. range. shows the Extended Essay scores of 50 DP students. ATL Score 1 6 a ≤ ≤ x x ≤ ≤ Frequency 5 1 10 9 11 ≤ x ≤ 15 15 16 ≤ x ≤ 20 15 21 ≤ x ≤ 25 5 26 ≤ x ≤ 30 5 By drawing and the b Using c Find d Draw a new table cumulative your an a cumulative estimate with for correct construct frequency the upper box-and-whisker Problem the frequency, curve, and diagram upper a write lower to boundary cumulative down for discrete frequency the median data curve. score. quartiles. represent the information. solving ATL 5 Brooke month recorded in Number this the of text messages she sent every day for a of 0 messages x ≤ 4 5 ≤ 10 Calculate thetext ≤ x ≤ 9 10 ≤ x ≤ 14 15 ≤ x ≤ 19 20 ≤ x ≤ 24 25 ≤ x ≤ 29 the values message 7 of a and b 3 in this 4 cumulative frequency 3 b Draw table c Use ≤ boundar y Cumulative frequency 4.5 10 ≤ 9.5 17 ≤ 14.5 a ≤ 19.5 24 ≤ 24.5 27 ≤ 29.5 b ≤ 34.5 30 cumulative your Hence x ≤ 34 1 for data. ≤ a ≤ 2 9.5 means values Upper 30 sent Frequency a number table: curve to represent frequency calculate the data in curve each a for value this in up including to ‘all the and 9.5’. data. the ve-point box-and-whisker summary. plot. 4.2 Getting your ducks in a row 115 6 The ages (in years) of the rst 30 people visiting the Tuileries Gardens in ATL Paris on a day are shown. 25 65 34 48 4 55 32 45 23 43 23 37 45 36 26 39 43 45 29 15 15 20 64 37 61 25 17 23 45 36 a Construct a grouped b Construct a cumulative c Use your visitors d 7 certain The give cumulative who Estimate frequency are the 25 frequency frequency or frequency information about for this data. curve. curve to estimate the percentage of under. percentage cumulative table of visitors who are older than 40. curves the ages Pedestrians 450 of pedestrians killed Great Draw a a in 400 2014. for the pedestrians. box-and-whisker diagram for the pedal 350 300 evitalumuC Draw Britain cyclists box-and-whisker diagram b pedal ycneuqerf a in and cyclists. 250 200 Use Compare the ages of the same scale 150 Pedal c cyclists the and draw one 100 pedestrians and pedal cyclists. box-and-whisker 50 diagram above the other. 0 10 20 30 40 50 60 70 80 x 90 Age Exploration 2 Use the number 1 In your class, record 500 random numbers between 1 and 30 the following button on generated your in random calculator, a way: spreadsheet Use technology two digits to produce random 3-digit numbers and record the last formula, of each, ignoring any over number For example: You 15 Random number record 951 a class, > 30 so ignore 23 430 record 30 measures 2 51 record a Compare intervals. grouped dierent of central your frequency sized are class table with intervals. carefully Use chosen technology intervals. to calculate with the As the other students who chose dierent class dierences? Continued 116 nd random 4 Representation numbers each combine them one tendency. results What tables. could and 7 823 try random Action 307 Construct or 30. on next page class set. into S TAT I S T I C S 3 Discuss class 4 how and Why choosing modal would it dierent class intervals aects the mean, A N D P R O B A B I L I T Y median class. not be sensible to represent this data in a stem-and-leaf diagram? 5 Represent whisker 6 Compare Reect If a ● set of Does Does and ● and data D is the grouped the of choice the class of curve and box-and- for too ● How can ● How do gives Switzerland in equal class interval diagram? and width aect and interval many real others. class class advantages likewise Age frequency 4 in median box-and-whisker table cumulative with Misleading The the modal aect intervals: estimate class? the of the mean? Explain. cumulative frequency curve Explain. disadvantages of having too few classes. classes. statistics data ever individuals be stand misleading? out in a crowd? 3 the ages of fathers at the birth of their rst child, in 2013. Freq Age Freq Age Freq Age Freq Age Freq ≤ 12 0 22 388 32 5522 42 2203 52 189 13 0 23 598 33 5766 43 1773 53 146 14 0 24 958 34 5612 44 1487 54 128 15 0 25 1414 35 5516 45 1187 55 95 16 2 26 1815 36 5225 46 856 56 86 17 13 27 2365 37 4703 47 717 57 61 18 26 28 3073 38 4126 48 579 58 45 19 69 29 3792 39 3705 49 442 59 40 20 132 30 4382 40 3210 50 365 21 251 31 5108 41 2703 51 290 Draw a width intervals were 2 a discuss Exploration 1 in results choice about Discuss Do data your the What ● the diagram. grouped under Calculate age of 70. an 1 frequency ≤ x ≤ What estimate fathers from 10, will for your table 11 the the ≤ x to ≤ represent 20, highest mean etc. class and this data. Assume the interval Use that all ≥ 60 174 equal the class fathers be? ve-point summary of the table. Continued on next page 4.2 Getting your ducks in a row 1 17 3 Peter uses the class intervals classes are roughly equal. 0 25, 26 29, ≤ 51 x ≤ ≤ x ≤ a Calculate new Reect ● In 30 ≤ x ≤ frequency estimate 34, that 35 ≤ x the ≤ frequencies 38, 39 ≤ x ≤ in 43, all 44 the ≤ x ≤ 50, for the table mean using and his the class intervals. ve-point summary from table. and discuss Exploration How ≤ grouped an summary ● x so 100 Construct this ≤ below that should 3, which best you 5 grouping represents group data the so of the data gives a ve-point data? that it accurately represents a data set? Consider: ● – the – class – the Do number classes width upper you of need and to lower boundaries consider the size of of the the class data intervals set? Summary The class width maximum class the has the that the dierence minimum grouped between possible the values For in grouped the equal, containing you to interval calculate are the the modal most class data. It an the nd Add the a of class value estimate frequency table to the the A cumulative frequency contains estimate frequency An interval) can median. column class grouped nd value. mean from and ● Find the each class or mid-interval value For interval by adding the upper lower class boundaries and dividing by Use the midpoint of each class interval the x ≤ and a C. organize the mixed logical dened (upper frequency 40, 40 from as: curve is < x ≤ against 45, the practice to you will represent be a logical For discrete ≤ x ≤ 40, data, 41 ≤ for x ≤ data 4 Representation on with the horizontal the vertical axis, axis. example: plot the upper cumulative class boundaries example: 45, against plot thepoint the cumulative halfway between to looking given. graph the class interval). 2. upper bound bound ofone (41), at str ucture. specically the highest calls 45. Communicating using of a on frequencies for grouped lowest plotted data, a bound of inter val mean. information structure 1 18 range bound continuous lower Objective: is cumulative < the calculate the boundaries frequencies In is and 35 v. mean of ● ● the (lower frequencies table: midpoint table – class the 35 a for cumulative upper 40 ● data a frequency. data, contains which widths interval highest frequency To class class the For is the interval. When is and at organizing information using 40.5. (40) and next S TAT I S T I C S Mixed 1 The All 290 of 35 masses 455 desert are 342 to hedgehogs the 465 nearest 480 are b listed Estimate of gram. 400 c 500 fox 460 328 284 436 280 the tails Given and 325 in that the interquartile the the shortest longest 368 295 310 390 435 450 315 505 510 495 310 400 375 4 The of 474 298 380 37 Construct a grouped represent the 463 State modal frequency the plot frogs at a zoo. Determine table curve 2 The table hazard the an shows class interval learner 10 20 that contains for the mean drivers’ marks mass. in 5 The speeds highway a for 30 c 3 m ≤ 27 9 28 ≤ m ≤ 39 21 40 ≤ m ≤ 51 18 52 ≤ m ≤ 63 23 64 ≤ m ≤ 75 19 the Construct The tails of a a a range of the diagram were cumulative cumulative random measured a the the masses cumulative data. 40 50 60 70 80 90 100 (grams) of cars passing recorded in a this speed camera on v (km/h) Number of cars frequency frequency sample in cm. in the ≤ 60 0 < v ≤ 70 10 70 < v ≤ 80 22 80 < v ≤ 90 61 90 < v ≤ 100 74 100 < v ≤ 110 71 110 < v ≤ 120 39 120 < v ≤ 130 17 130 < v ≤ 140 6 of 200 table. curve. adult The results Calculate cumulative frequency an estimate for the mean speed cars. curve. b Here is same a cumulative frequency table for data. 200 Speed, Number Cumulative 175 v of cars frequency ycneuqerf evitalumuC v ≤ 60 0 0 v ≤ 70 10 10 v ≤ 80 22 32 v ≤ 90 61 93 125 100 75 50 25 10 15 20 25 Length a (km/h) 150 5 Estimate the median 30 35 40 45 50 v ≤ 100 74 a v ≤ 110 71 238 v ≤ 120 39 b v ≤ 130 17 294 v ≤ 140 6 300 x (cm) length of fox of are y 0 a table. 60 the represented shows marks. a foxes a data. solving are v ≤ Construct the Frequency 16 b for the Speed, Estimate cm test. m a 11 label class. estimate perception Mark, was and to Problem Calculate length data. median. d length draw Construct Mass c the 360 0 b cm, box-and-whisker 80 frequency a for 370 450 450 range sample. box-and-whisker 347 P R O B A B I L I T Y practice masses here. A N D tail in the sample. Write down the values of a 4.2 Getting your ducks in a row and b 1 19 the c On graph paper, frequency curve construct to a represent cumulative this b information. The cumulative lengths of the frequency diagram shows the halibut. y d 25% By speed the the speed upper on this grams, graph i the median ii the upper of to a quartile, stretch frequency limit. of curve selection estimate highway. shows of the 200 160 evitalumuC Use in the limit cumulative weights, a exceed ycneuqerf The cars calculating the 6 of oranges. estimate: 120 80 40 0 5 quartile. 10 15 20 25 Length Give your answers to the nearest 10% of the oranges weigh more than x 40 45 x 50 the interquartile range. grams. c Find 35 gram. Estimate b 30 (cm) The sherman returns any sh smaller than x 20 cm to the river. Calculate an estimate for y the number of sh he returns. 80 d Fish greater than 28 than or equal to 20 cm but less 70 ycneuqerf cm are classied as small sh. Fish 60 that are 28 cm or longer are classied as 50 large sh. evitalumuC 40 Estimate the number of sh in each category. 30 e The sherman sells small sh for $6 and large 20 sh for $10. Estimate how much money he 10 will 0 50 55 60 65 70 Weight 75 80 85 90 95 earn if sherman catches all the sh. 8 The cumulative frequency curves show the ages (grams) foreign male Switzerland A sells x of 7 he 200 halibut. The in and foreign female residents in 2013. table y shows the nearest lengths of these halibut to the cm. 1100 Male Length, x (cm) Frequency 1000 10 < x ≤ 15 24 15 < x ≤ 20 38 20 < x ≤ 25 53 25 < x ≤ 30 39 30 < x ≤ 35 29 35 < x ≤ 40 10 40 < x ≤ 45 7 900 Female ycneuqerf 800 700 evitalumuC 600 500 400 300 200 a Calculate the an estimate for the mean length of 100 halibut. 0 10 20 30 40 50 60 70 80 90 100 Age By constructing plot, and 12 0 4 Representation compare foreign a double the female ages box-and-whisker of the residents. foreign male x S TAT I S T I C S ATL Review in A marine in a local records trout and biologist river. the from To lengths the is sustainability studying the of rainbow nearest a trout centimeter, sample of 100 d Copy and this she 75% of over ____ trout The the rainbow other rainbow cm in x (cm) trout species, lengths of < x ≤ 27 1 of 27 < x ≤ 29 5 29 < x ≤ 31 9 other These so 100 feed the 31 < x ≤ 33 21 33 < x ≤ 35 29 35 < x ≤ 37 19 37 < x 39 16 Male 0 i ≤ female species, are sh records and 100 of the male sh shown in cumulative frequency the the same river. box-and-whisker sh 4 8 12 16 20 24 28 table 32 Estimate the number of Estimate the 36 40 44 48 52 female sh that are the rainbow trout in the river . number of male sh that are for than 75% iii a cumulative frequency Hence of the rainbow trout. the cumulative frequency estimate curve to write other summary Reect and How you have for the species in percentage the river that of the 75% sh of the a rainbow ve-point the curve. of trout can feed on. data. discuss explored the statement of inquiry? Give specic examples. Statement of Inquiry: How and quantities trends in a are represented can help to establish underlying 56 (cm) data. Draw Use smaller sh smaller c sh from smaller than 75% of ii a on biologist Length b are diagrams. Female this trout length. Frequency 25 Construct statement: rainbow e Length, complete river. Rainbow a P R O B A B I L I T Y context Globalization 1 A N D relationships population. 4.2 Getting your ducks in a row 1 21 How did that happen? 4.3 Global context: Objectives ● Drawing a Identities Inquiry scatter diagram for bivariate ● data F ● Drawing ● Understanding a line of best t (regression line) by interpreting the questions How SPIHSNOITA LER ● Using sets of technology lineofbest can you describe between two sets of How you draw a relationship data? do and use a line of correlation best betweentwo relationships eye ● and and t? data to obtain the equation of ● a C t How does aect ● Does ● Do our the way ability correlation to data is make indicate represented predictions? causation? D ATL Information Understand and use help to and clarify want to be like everybody else? literacy technology systems 4.3 Statement of Inquiry: Generalizing I representing trends among relationships can individuals. 12.3 E4.1 12 2 S TAT I S T I C S Y ou ● should represent on the already data by Car tesian know how plottingpoints 1 table dierent Plot to shows calculate the mean of a set of data 2 on represent identify an outlier in a set of data this 1, Introduction F ● How can ● How do Investigating Ifyou can valueof the you a Exploration table The maximum shows to a and relationship use between relationship variable The draw predict 6, (£) 5 4 2.1 1.70 4.5 3.60 3.8 2.90 2 1.60 2, mean 4, 6, 8, 2, of 7, whether can be Explain 6, Price 8, 9, 1, 9, any set 4, of of 6, 2 these classied your 9, this as answer. 11, 15, 20 correlation describe relationship identify one you to 6, (kg) the plane data. 2.70 values outliers. potatoes. Car tesian 3.4 Determine data of of 0.40 Calculate 3 a cost 0.5 numbers: ● the weights points Weight ● a line variables between the of value two of between best is a sets of data? t? key topic variables, the two you in Statistics. can often use the other. 1 12 students’ possible marks score on for each Mathematics test was and Physics tests. 8. Student A B C D E F G H I J K L Mathematics 8 6 7 5 4 8 5 6 7 7 3 2 Physics 8 7 6 4 4 7 5 5 7 6 3 3 1 Draw scores a graph on the For (6, 2 example, 7), and Explain between so with Use score, for on. whether the Mathematics y-axis. (Mathematics P R O B A B I L I T Y to: The plane A N D a Physics score) student A, Do join not your students’ scores sensible graph plot the on scale, to the the and x-axis label represent point (8, each 8). and the For Physics axes. Plot student’s student points scores. B, plot points. suggests Mathematics that and there Physics might be a relationship marks? Continued on next page 4.3 How did that happen? 12 3 3 Describe patterns 4 5 The teacher also got Draw a a line the on When as Discuss the Correlation the one a on for in the in Is graph close the is Data measure the relationship of the two there are the association as to is the two the these one subject one relationship way does quantitative and the bivariate two variables. dependent data variables. variable decreases increases, there x of the The the is correlation. y Positive When the line. called other negative in Which between the y mark shows x-axis When correlation. whether justied? Physics. variables is good between on increases increases, a claim best and points represented from got this that Mathematics Determine class. who other. your data. the students the how shows y-axis. is in variable variable other positive line see student that mark marks diagram you every claimed independent variable to good slope? scatter The patterns straight between A any apply the plotted points, closer you the x correlation points say points are there are Negative to close is a a to a linear straight straight line correlation line, the correlation drawn through between stronger the the the correlation variables. Strong Moderate correlation correlation 12 4 4 Representation No middle variables. linear correlation between Scatter are diagrams also called scatter plots scatter graphs. or S TAT I S T I C S The scatter between the graph higher the Practice For you Mathematics each Physics drew and in Exploration Physics scores. 1 shows The strong higher the linear A N D P R O B A B I L I T Y correlation Mathematics score, score. 1 scatter plot, describe the form, direction and strength of the ‘Form’ association between the variables. Interpret your description in the or ofthe is linear context non-linear. data. ‘Direction’ 1 a b c y erocS x Height Amount e gnitaeH fo thgieW line of of so can a best t that best x-values draws ytilibaborP llib rac line points a is a the line line, of line equally through mean best called x Temperature straight are passes and draw is they t similar x mileage of t the x revision y y Gas of f y You ni eohS t rA d is negative. tset ezis erocs x score or y y Mathematics A positive drawn through distributed the the by on point the either middle side where x Height of is of the the a set line. mean of data The of the y-values. eye. A can line also trend GDC regression The line, or by graph plotting calculating the of be best line. software points mathematically. You can x-value, use and of the vice line of best t to predict a y-value when you know an versa. 4.3 How did that happen? t called 12 5 a Example The table 1 shows dailysales of ice Temperature, Sales, a y x the average cream (°C) ($) Draw a in daily temperature in °C for a week and the dollars. Mon Tue Wed Thu Fri Sat Sun 17 22 18 23 25 19 22 408 445 421 544 614 412 522 scatter diagram line best of this data and draw a line of best t through the points. b Use the temperature of t to predict the sales of ice cream on a day when the is20°C. a Calculate the mean Calculate Ice cream temperature the mean . sales . sales y Plot the points from the table and 650 the point Draw a line . through M and through 600 the middle of the other points. 550 )$( Tip selaS Use a transparent 500 ruler so you can see M all the and points below it. above Pivot 450 the ruler through the point the to best nd position. x 17 18 19 20 21 Temperature 22 23 24 25 °C Draw b When the temperature is 20°C, predicted sales are and 12 6 4 Representation a line from x = 20 $460. read o the y value. S TAT I S T I C S To draw ● Calculate ● Plot ● a line the Draw the best t mean by of line The x and on the the through points P R O B A B I L I T Y eye: point a points. of A N D scatter and should be mean of diagram. through evenly y the middle distributed above of the and other below theline. Practice 1 The 2 table shows ● Reaction ● Height, ● Weight, ● Time, Reaction Height in seconds, time Draw separate Plot height ii Plot weight iii Plot iv Plot height Comment 1.68 Use took line visual responses of on the shoelaces. E F G H I J 5.3 4.6 7.7 3.7 4.6 3.6 4.2 4.8 5.3 4.6 1.64 1.50 1.67 1.75 1.45 1.35 1.87 1.67 1.56 1.70 60 60 64 76 48 45 75 75 52 60 9.1 10.5 13.4 9.6 10.5 9.2 8.8 8.5 10.4 6.3 scatter the diagrams: x-axis the best their D and x-axis distance on fasten C the on to on x-axis t on form, and the on reaction x-axis and each weight direction and y-axis. distance and fastening scatter the on fastening time on the time the y-axis. on the y-axis. y-axis. diagram. strength of the correlation in each diagram. the m on reaction c Use measure B (cm) i scatter to A (s) four a test taken (kg) Draw f a students: kilograms b e in 10 meters distance Fastening d on (m) Weight a distance, in in data line of best t to estimate the weight of of best t to estimate the reaction a person who is tall. the 12 Explain line seconds which to of fasten your their graphs distance of a student who shoelaces. would give the most accurate predictions. 4.3 How did that happen? 12 7 2 The table shows information on road deaths and vehicle ownership in ten countries. Vehicles per 100 Road deaths per 100 000 Countr y population population UK 31 14 Belgium 32 29 Denmark 30 22 France 47 32 Germany 30 25 Ireland 19 20 Italy 36 21 Netherlands 40 22 Canada 47 30 USA 58 35 a Draw and a scatter road show any b Draw c The a line road per of best death of per t data 100 road to ● vehicles per population for How does deaths the represent the Switzerland population. Interpreting C with 100 000 100 on population the y-axis. on Does the the x-axis graph correlation? 25vehicles number diagram deaths per Use 100 000 patter n is in missing. your line data. Switzerland of population the best in t to has estimate Switzerland. correlation way data is represented aect our ability to make predictions? You can use a GDC, graphing software or a spreadsheet to plot scatter ATL diagrams, models add the a the process value of line of best relationship Technology nds a uses vertical called the linear t squares’ to of to produce the regression displacements ‘least and between independent an equation nd the the points a line line of from that best the will y P 6 1 4 P 5 3 P 1 x 1 2 1 12 8 the 4 Representation 3 4 This and predict 2 P 2 t. line x P for line that variables. nd variable P the y method then for a uses given S TAT I S T I C S Each the square line. for the try to the in The sum nd of the squares table diagram squares these line and Example The the least squares. of the square t nds With some yourself by the of sum of the the vertical line that GDCs or plotting a their distance gives the graphing line from a point minimum software through (x , to value you y ), P R O B A B I L I T Y can showing areas. 2 a Use b Comment c Use the technology on weight to the graph Name best minimizing gives the is method A N D to Height and draw form, a scatter direction estimate (cm) height the of students. diagram and weight Weight 10 and strength of (kg) a 162 of cm Name Alex 168 77 Frida nd the the line of best t. correlation. tall student. Height (cm) Weight 159 (kg) 87 Bea 149 45 George 195 94 Chip 173 65 Harr y 144 53 Dave 166 59 Inge 176 65 Erin 185 79 Jepe 180 87 a 1.1 1.2 Example 1.3 RAD 2 95 80 thgieW User your GDC to create a line 65 of best t from the data. 50 y 140 150 160 = 0.7445 • 170 x + 180 −55.09 190 Height b There the c is moderate heights Using the and Practice linear correlation between weights. graph, approximately positive a 65 height of 162 cm would correspond to a weight of kg. 3 ATL 1 The table gives the height and weight of 14 adult mountain zebras. Height x 1.37 1.17 1.2 1.34 1.42 1.42 1.37 1.48 1.51 1.23 1.57 1.29 1.30 1.44 257 171 185 214 315 271 242 329 314 185 356 228 230 285 (m) Weight y (kg) a Use b Find c Comment d Use with technology the the to equation on line height the of draw of scatter line correlation best 1.38 a the t to of diagram. best t. between predict the the height weight of and an weight adult of the mountain zebras. zebra m. 4.3 How did that happen? 12 9 2 There leg Leg x are to run girls 1000 in an athletics club. The table shows their m. 82 91 85 93 86 95 70 87 90 75 91 80 245 210 243 220 240 225 250 243 230 248 220 240 run a Using b Find c Comment the The table cost of y of Plot b Find machine the c Use your could to when ● Do I length and the to 1000 time taken to ● Measurement ● Clerical error the time r un m for student a cm. of the cylinder purchased new at in the a washing same machine and the shop. 52 55 62 66 230 350 400 550 550 600 620 700 on of a scatter of the best t of diagram. line to 50 of best estimate t. the cost of a washing machine with cm. predictions want to predict 84 correlation arise due leg 48 diameter Does be t. between 41 line ● can t diameter equation cylinder outlier diagram. best 36 Making D of 33 points the scatter line correlation best the ($) a a the measurement shows the the of m. x (cm) Cost, a on line leg draw equation 1000 Use Size, technology , the with It to length r un An 15-year-old time (s) d 3 and (cm) Time y twelve length to in a be like variety human error indicate error, (wrong (writing the causation? everybody of else? ways. categorized by: units) results incorrectly or misunderstanding the question) ● Instrumental However, In 4.1 you whether If you think An it not think it is could used or a at the 13 0 the to the be is (faulty a IQR outlier an to is due point, of point determine the anomaly distance instruments) legitimate include legitimate outlier look error the outliers to it in which the in human must the data be 4 Representation outliers; the data error, kept data. point caused To these now it is results. your decision set. remove the data point; if you in. identify from the outliers line of best in bivariate t. data, S TAT I S T I C S Exploration The Olympic medal Year P R O B A B I L I T Y 2 Games distance A N D for are the held men’s every long four jump years. event The over table a shows period of the gold 28years. 1956 1960 1964 1968 1972 1976 1980 1984 7.83 8.12 8.07 8.90 8.25 8.35 8.54 8.54 Use ‘number of Long jump years after (m) onthe (0, 1 Use a line GDC of best 2 Describe 3 One or t the jump graphing for the software draw a scatter diagram and nd x-axis. 8, …) the data. relationship stands to 4, out that from the the graph others. shows. Is it much further from the line of Discover best t than the other points? Is it an How are does based this outlier aect the line of best t and any predictions that onit? by Find the line of best t without the anomalous jump. Use this line the gold medal long jump distance for that Olympic gold for scatter but it graph does other not it is temperatures. that a a relationship change example, over the a fall in the in the between one of of years number cause and two variable number period Demonstrating linear Reect that For measured unlikely astrong show show (causation). temperature But may have of eect a a and has much (correlation), change global negative pirates is variables causes pirates this in the average correlation. caused harder a Bob year, In video called Long Olympic Shadow New by York The Times higher than showing correlation. and discuss Exploration You 1 cannot 2, yo u used the l ine of be st t to p r e dic t a that the v al ue relationship within in search Beaman’s know ● long medal year. particular A jump to for estimate this researching the jump 5 more outlier? about 4 1956’ the range of d a ta you were give n. W as it appr opr iat e you to can see between dothis? ● The t modern to predict jumped in Olympic Predicting In the the values began winning original Games interpolation. iscalled Olympics 100 jump Greek years inside the Predicting in in 1896. in this Could year? Olympic the range values you What Games use your about 1500 line the years of best distance earlier, or of the given the data still hold or lower values sets for will higher data than those given. future? outside two data range is of called the given data extrapolation. general, interpolation is more likely to give an accurate prediction than extrapolation. 4.3 How did that happen? 13 1 Exploration The table period same shows and time Visitors to Revenue the number revenue of from visitors to registered the nail Bahamas salons in for the a seven-year US during the period. Bahamas salons the 3 2008 2009 2010 2011 2012 2013 2014 4.6 4.6 5.3 5.6 5.9 6.2 6.3 6.3 6.0 6.2 7.3 7.5 8.2 8.5 with visitors the (millions) from nail (billions of USdollars) 1 Draw a scatter Bahamas 2 Describe 3 Draw when 4 a on the line there Does it 3 of the factor, You an 5 to t that and the in use it make from the to visitors the there is of other. can an nail on the to the y-axis. variables. the from revenue the occur from are but both line of between association salons, They salons nail salons Bahamas. predictions revenue the two results, nail predict to relationships Obviously increase these revenue between and to illustrate and million sense shows Bahamas notcause best are obscurevariables. to x-axis correlation make Exploration diagram the best the between an t? most the increase dependent on visitors in one does another time. cannot Practice use correlation to show that two variables are related to each other. 4 ATL 1 The average consecutive a Use prices years of are technology to a liter given draw of milk in January in the UK tabulated for six here. a scatter diagram and line of best t. Month Put at the zero. dependent Then 24months, b c Use the i July 2009 ii July 2012 iii January In January 13 2 January on 2010 is the 12 x-axis, with months, Pence per January2009 January 2011 is Jan 2009 23.73 Jan 2010 24.67 Jan 2011 27.36 Jan 2012 28.08 Jan 2013 31.64 Jan 2014 31.52 etc. line Compare variable of best t to estimate the average price of milk in: 2015 2015, this to the average your price prediction. 4 Representation of milk Explain was any 24.46 pence dierences. per liter. liter S TAT I S T I C S 2 Discuss logical a what a c period human strong b The and correlation screen medium was Between you the Arm Height Use and Use c the of Discuss in any Group Group 1 between the Labradoodles annual in number Denmark was amount and the of time quality a of person sleep spent that looking they at reported a that there number oenders was TV sent have and of to span strong, positive bought in linear the UK and prison. longer arm a licenses arms for 10 than short people? students. 170 177 177 188 196 200 182 162 180 166 167 173 176 182 184 186 to draw a y-axis. is t diagram the predict line of with best (interpolate) arm span on the x-axis t. the height of a student cm. outliers? Use scatter Find to 171 If this so, new remove line to them predict from the the list height and of a nd the student new whose cm. dierences sets 2 2 grams. between b and c drawing Here line data a number of pins and 24 28 29 31 33 5 7 11 10 14 15 16 9 11 20 two groups total Use scatter that and which a weight pins. best to calculate of the this pins on the Use the mean drawing method diagram. of their data: 24 a of the 20 to weight pins technology x-axis and calculate and to of drawing divides the by mean draw weight a on a pin. the weight. scatter the y-axis. t. two nd drawing weight record 17 number decide their and 13 the of is pins 7 in draws with of of drawing Determine mean of 165 171 nds unreliable weight the people best work of the Group correlation 160 pins students Find d draw 156 (g) diagram c you solving of number b of t. is the weight Weight a Can 155 the any weigh Number The show. negative. the height span best span Students on line line total lists arm there the 2005–2015 tall technology height Problem 4 that (cm) Are arm d below population day and young (cm) whose each years of here span the between think table years, between night The b 10 and computer Do analyses positive. thenumber a of births correlation 3 correlation P R O B A B I L I T Y conclusions? Over of the A N D of a the new weights line of are best unreliable. t. Use it to Remove nd the the mean pin. group’s drawing method gives the most reliable estimate of the pin. 4.3 How did that happen? 13 3 Summary A scatter two diagram quantitative variable is dependent two shows variables. represented variable variables is the on on called relationship The the the between x-axis bivariate and Data line the independent y-axis. A equally the line from of between is two increases as correlation. a measure variables. the other When of the When one variable of t a is set distributed t is of straight data on passes the the a of line either of the so side through mean drawn points the that of the through they line. are The point x-values and is the y-values. association one increases, best best where data mean Correlation of middle variable there is To draw a line ● Calculate of best t by eye: positive decreases as the mean of x and the mean of the y other increases, there is negative correlation. ● Plot ● Draw the point on the scatter diagram. y y a middle be line of evenly through the other M and points. distributed through The above the points and should below the line. An outlier outliers Positive correlation Negative closer the points are to a straight in line, data point the anomaly correlation between the data, in the look data. at the To identify distance from the line of best of t. the Predicting stronger an bivariate correlation the The is x x values inside the range of the given variables. data is called outside the interpolation. range extrapolation. more likely to In of the given general, give an Predicting data is values called interpolation accurate is prediction than extrapolation. Strong Moderate correlation correlation Mixed 1 The linear practice table leaves No correlation gives that fell the to length the and width of 10oak a ground. length b Length (mm) Width Represent Comment 38 c By width 146 44 119 38 149 53 a Two of contain on a and scatter width correlation diagram, on the with y-axis. between length mean best length and mean width, t. solving these a of leaves. statements mistake. about Explain correlation what the mistakes are 36 and 38 a how the ‘There is income 151 51 147 43 123 33 128 42 b ‘There of c a high statement strong objects a two and the and 1999 time the between correlation the correct. gender.’ number between stations.’ be between their correlation and positive speed between could correlation workers America is average 4 Representation a hot ‘There third of is Miss using 13 4 the the the line Problem 2 135 data x-axis on of nding draw 89 the the (mm) and 103 on of the age murders and2009.’ between taken by a the train S TAT I S T I C S Objective: ii. select D. Applying appropriate mathematics mathematical in real-life strategies A N D P R O B A B I L I T Y contexts when solving authentic real-life situations In this review diagrams, outliers, you using in in Identities Florence’s seemed height Age to use the extract mathematical information strategies and of drawing determining the scatter reasons for context relationships parents short for a to situations. and over have technology real-life Review 1 will were her 36-month (months) concerned age and they that she recorded 2 her period: 36 48 51 58 66 72 86 90 91 93 94 95 There 10km are 12 run. of students The of hours to complete training the Training Height (cm) table training shows per for the week Draw b Use c a scatter this diagram scatter height at Could you diagram age 42 use to of diagram this to charity and the number time taken run. time Time to (hours) a a average complete run (minutes) data. estimate 10 56 9 54 13 53 her months. this predict data her and the height at scatter age 4 62 26 42 7 66 18? a 11 54 6 66 7 68 22 39 5 70 10 67 Comment training on time the and correlation between the complete time to therun. b Estimate student c Determine to predict student Reect and How have Give specic you how who long trains the 18 whether how who long trained run would hours you the 50 per could run take use would hours a week. per this data take week. discuss expl o red the statem ent of i nq uiry? exam pl es. Statement of Inquiry: Generalizing to clarify and trends representing among relationships can help individuals. 4.3 How did that happen? 13 5 a What are the chances? 4.4 Global context: Objectives ● Representing Identities Inquiry sample spaces in tables, lists ● and and relationships questions What are the dierent ways of F diagrams ● Drawing two-way CIGOL ● representing tree Calculating and diagrams, Venn diagrams ● and tables probabilities two-way from Venn diagrams ● How do of event? an What a you are the calculate Using with tree and diagrams without Understanding ATL the advantages probability to calculate probability probabilities of the and dierent representations? replacement ● ● space? C tables disadvantages ● sample informal ideas of randomness Does randomness aect the decisions D we make? Communication Understand and use mathematical notation 4.4 Statement of Inquiry: Understanding using logical health and making representations and healthier choices result from systems. 15.1 E15.1 13 6 S TAT I S T I C S Y ou ● should calculate already know simple how 1 This probabilities blue d set the notation, specically complement of a 2 is or blue not a Using set Let c diagram 3 is the on yellow set the 5, notation, numbers 6, 7, 8, Write In a like 7 down group of children n(P) a Venn 핌 = Write and set P of 10. {1, 2, down 3, the n(P′). children, 16 like set 10} the than P′. 24 bananas, Draw 9, of write less Universal elements a Venn once. What lands yellow? prime 4, draw it white or e b ● spun that yellow c use spinner blue b ● P R O B A B I L I T Y to: probability a A N D of them 10 of like them apples and both. diagram to represent this information. Representing F Th What ● How mathmatis looking and ● for ar do you as 1 A in nw rstaurant prson insid pays that ways alulat vnts vnts th of proaility involving ar rprsnting rpatd of han you is will an a sampl spa? vnt? alld gin Proaility. to s how By to prdit proailitis. Exploration a dirnt hind pattrns alulat th outcomes thir ithr town ill, says runs thy ‘Your a ar promotion givn mal a today to gnrat sald is usinss. nvlop fr’ or with ‘Sorry, a Bfor mssag ttr luk nxttim’. Th rstaurant During and a thr ownrs on-hour of thm laim priod gt a that on th th winning han rst day, of a ight winning mssag ustomrs pay is 1 thir in 6. ill, mssag. Th To tst that th rstaurant’s laim is orrt, you an st up a 1 Assum that thy ar orrt and a winning mssag indd appars in of vry 6 sald nvlops. Th proaility of winning in is thrfor 6 is tru numr as rolling 1 Roll a di 2 Rord 8 a six tims on to a fair numr simulat of 6s di; a you di. 8 popl paying thir ills. ould rord 4s, long as wr th for on th standard sam of 1 any out proaility simulation. you as 3s or you onsistnt. roll. Continued on next page 4.4 What are the chances? 13 7 3 Rpat this pross 30 tims. Comin th rsults for othrs ina Your GDC othr softwar or spradsht. run Basd on th omind rsults of th simulation: that 4 Calulat th prntag of outoms whr 8 ills paid rsultd prform in th 3 xprimnt winnrs. thousands 5 Calulat th prntag of outoms with no vn winnrs. Ddu th most ommon numr of winnrs in 8 ills Try Disuss whthr Do think you Reect In ● and Exploration Asid from simulat ● What Simulation prdit is onstruting Th sampl outoms Whn you of di, tool happn spa a who had printd 3 too winnrs many wr just winning with luky. in mssags? 1 of is a 1 for winning 8 futur. th ar spa an two using is th You of possil st or hav usd to 6? likly? also nd of vnts and proailitis y situation. omplt list, a tal outoms: notation you proailitis an th a in most xprimnt It ould mssag popl rprsntation thr sampl way(s) invstigat th xprimnt. oin, othr from to in spa S, an what winnrs powrful from th a proaility sampl toss Dsriing rolling might a popl 1: th a 8 rstaurant discuss numr what th th givs: st or a of = all possil diagram. Hads S {H, (H) and Tails (T). T}. ATL H and For T any ar sampl outoms In A in Exampl ours So P(A) th or + only spa th 2, it S, sampl A and dos P(A′) possil = A′ P(S) outoms = spa 1, aus must togthr so thy for ovr ah th xprimnt th th whol sampl P(S) = proailitis in Exampl 1 P(A′) = 1 P(A) = rprsnts proaility of A 2: th P(A) + P(A′) 5 + = not = 1 6 6 proaility of spa. th aus 5 of vnt A ourring. ourring. P(A) 13 8 spa, = 1 6 P(A) on 1 6 So sampl not. 1 Using whol our. ovr 4 Representation + P(A′) = 1 of this and paid. ompar 7 or millions tims. 6 an simulations P(A′) is th ithr th your rsults ndings Exploration 1. S TAT I S T I C S Example Two fair P R O B A B I L I T Y 1 6-sidd Rprsnt A N D all di th a a list b a tal c a diagram. a S = ar rolld. possil On outoms di is grn and th othr is orang. as: {(1, 1), (2, 1), (3, 1), (4, 1), (5, 1), (6, 1), (1, 2), (2, 2), (3, 2), (4, 2), (5, 2), (6, 2), (1, 3), (2, 3), (3, 3), (4, 3), (5, 3), (6, 3), As (1, 4), (2, 4), (3, 4), (4, 4), (5, 4), (6, 4), a set (1, 5), (2, 5), (3, 5), (4, 5), (5, 5), (6, 5), (1, 6), (2, 6), (3, 6), (4, 6), (5, 6), (6, 6)} b 1 2 3 4 5 6 1 (1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6) 2 (2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6) 3 (3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6) 4 (4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6) 5 (5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6) As Th tal most is a th ommon rprsntation sampl 6 (6, 1) (6, 2) (6, 3) (6, 4) (6, 5) table of a spa. (6, 6) c As Practice Objective iii Mov Make in 1 all sure your Th roll C: Communiating twn you list dirnt outcomes representations on Rprsnt suh th of sample gam rsults sampl of mathmatial systematically oard di forms in spa a for and include rprsntation all the possible outcomes spaces. Daldøs sor of rolling uss I, 4-sidd II, two of III or ths (ttrahdral) di. Th IV. di as a list and as a tal. For 2 A fair oin is tossd thr th sampl spa Q2, mak a tims. list Dn diagram 1 Sandinavian of a for this xprimnt. of th possil outoms. 4.4 What are the chances? 13 9 3 Copy and rolling omplt two 4-sidd this sampl di, ah spa with 2nd tal fas for th sum numrd 1, of 2, th 3 sors and from 4. die In 2009 thrw 1 2 3 eid a ts1 2 strt ar – slls and typs typs for th ttrahdral di (4-sidd) ah 7 two thr spa Eah of two ox. Thr othr two multiply th a a of th v sandwih fruit hois a v to 2 togthr. of a 6. a di th a draw 1 to th a sampl a 5. pi without a 7, world stting rord. hans 1 in 1.56 of this trillion. A ard to or a th fruit. is outoms. drawn from outoms. from spa of possil numrs ard List rolld th possil Gatsy anana. ar rprsnt ontains Draw Afrian or and (6-sidd) to numrd You South orang sandwih rprsnt On to – appl, spa ards ards. – normal sampl spa numrs numrs of of and ontains sampl sts ontains possil Construt oxs Draw ar di 7 simultanously. 6 of 5 vndor Gyro sampl A nw Th Grk 5 tims throwing 4 A woman 2 3 4 a pair 4 154 1 a 0 to ah 4 and st rprsnt th and this information. Problem 8 Th S = solving sampl {(1, spa H), Dsri (2, th Rprsnting for H), an (3, xprimnt H), (4, H), is: (1, T), (2, T), (3, T), (4, T)} xprimnt. sampl spas allows you to ount spi outoms. Gams hav An event is a sust of th possil outoms listd in th sampl of n han playd spa. sin anint tims; arhaologists From how th sampl many ways spa th of vnt sors on ‘gtting th th two sam di in Exampl numr on oth 1 you di’ an an s our. disovrd in Turky from Us apital lttrs for vnts, lik A, B, C and ATL A = gtting th sam numr on oth dn th vnt. For 3000 14 0 of vnt 4 Representation dating bce and xampl, Mahjong tils from bce dating di. 500 China. Proaility hav di in S TAT I S T I C S Example You roll a th b two a A two 6-sidd numr dirnt gtting di. on Calulat oth th proaility of gtting: di numrs. th sam numr on oth di. Dene 1 2 3 4 5 6 1 (1, 1) (1, 2) (1, 3) (1, 4) (1, 5) (1, 6) 2 (2, 1) (2, 2) (2, 3) (2, 4) (2, 5) (2, 6) 3 (3, 1) (3, 2) (3, 3) (3, 4) (3, 5) (3, 6) Identify same 4 (4, 1) (4, 2) (4, 3) (4, 4) (4, 5) (4, 6) 5 (5, 1) (5, 2) (5, 3) (5, 4) (5, 5) (5, 6) 6 (6, 1) (6, 2) (6, 3) (6, 4) (6, 5) (6, 6) A′ = gtting dirnt numrs on th two the set Count on A′, all the the with numbers other your two are or a spas from Prati 1 to answr ths Calulat th 4-sidd proaility of gtting two 4s whn you P(A′) Two th 4-sidd proaility of not gtting two 4s whn you roll in gams ard di. ttrahdral Calulat rol-playing and di ar rolld and thir sors ar th proaility of gtting a sum of Calulat th proaility of gtting a sum lin hav low qual to A fair oin a thr b two c no is tossd thr tims. Calulat th Th and proaility a 9 dot thm what or to valu 5. thy 3 6 addd. 5. not trading gams. indiat b di di. oftn a 1 ommonly numrals 2 = roll usd Calulat two . . . qustions. ar b A 2 sampl two the of use + Non-uial 1 in outcomes P(A) Us the dice. complement . . . Practice event. with both outcomes dierent di. the outcomes number The b P R O B A B I L I T Y 2 sam = A N D of rprsnt. gtting: Hads Hads in any ordr Hads. 4.4 What are the chances? 141 4 Calulat whn 5 Calulat whn 6 Hr 52 th you th you is proaility roll a th that ttrahdral sampl playing that ttrahdral proaility roll th two spa th di for sum of th sors will a prim numr of th sors will a prim numr di. sum and a normal hoosing a ard (6-sidd) from a di. standard dk of ards. A, K, alld ards. Lt A th vnt Lt B th vnt ‘gtting a Lt C th vnt ‘gtting an a pitur ard’. hart’. vn numr’. a Calulat th proaility of ‘gtting a pitur b Calulat th proaility of ‘gtting a hart’, c Calulat P(C ). d Calulat P(A′). e Calulat P(B ′). f Calulat P(C ′). Problem 7 ‘gtting ard’, or or P(A). P(B). solving A ag ontains A ll is 20 hosn lip-on at iyl random from lls. th Som ag. R is ar rd th vnt and som ‘piking ar a lu. rd ll’. 1 If P(R′) = , nd th numr of rd iyl lls in th ag. 4 Probability C ● What ar th proaility Exploration 1 a Writ fair b down diagrams advantags and disadvantags of th dirnt rprsntations? 2 th sampl spa for rolling a 4-sidd di and tossing Basd and on your tossing sampl spa, alulat th proaility of rolling a 1 Tails. Continued 14 2 a oin. 4 Representation on next page Q and th J ar pitur S TAT I S T I C S c How and 2 a Writ b Basd vn c down Stat proaility tr diagram possil B) a on vnt: a two × spa, di to for th rolling alulat and 2b to proaility of rolling a 1 Tails? a 3 rlats proaility proaility of of th on to two th ithr di. proaility th rolling 4-sidd sond of proaility a rolling an on. of rolling an 3. vnt is atd y th vnt. indpndnt vnts A and B ourring is: P(B). rprsntation and tr oth rolling vnt: th rlat P R O B A B I L I T Y alulat of th a sampl spa, proailitis of so you mor an than s on all th vnt. 3 drawing numr 2nd is th 1b spa rst answr othr P(A) outoms Example 1st = th and of to tossing sampl on your th of sampl whthr of and By your how P(A answr th numr outom A on Dtrmin Th your proaility numr vn 3 dos th A N D diagram, of two th rolling 1st th alulat 6-sidd th proaility of rolling an odd di. di. 2nd di. 2nd die Draw 1 odd a pair outcomes of branches (odd or even) to represent for rolling the the two 1st die. 2 1st die odd 1 For 2 each outcome on the 1st die, draw the two 1 2 even possible There 1 outcomes are three for odd the 2nd numbers die. (1, 3 and 5) and odd six possible outcomes. 2 1 2 even P(odd) = P(even) 1 = 1 even 2 Identify P(odd, odd) event tree the branches P(odd, odd), diagram. along those that shown Multiply the represent in red in the the probabilities branches. 4.4 What are the chances? 14 3 Reect and discuss Half 2 of all outoms ● Would it hang th answr in Exampl 3 if you put th ranhs 2nd di rst in th tr What do you ranhs? noti Explain aout why th this sum of th proailitis on any pair of Why do Practice 1 A ox w multiply ontains thr proaility that a rand-B Copy proailitis and that rand-A a attris rand-A attry is omplt faulty th tr attry is on and ah ranh? is svn faulty is rand-B 0.3, and attris. th proaility 0.4. diagram to show all th proailitis. 0.3 faulty 0.3 A not faulty faulty B not b 2 3 A attry is that th i a faulty ii not Two fair a faulty a Draw b Calulat Jams H tr starts to random from th ox. diagram to to rprsnt proaility nd draw th this that oth proaility tr th possil oins of rolling 14 4 omplt th th die tr proaility two Hads. sixs diagram. second not Calulat proaility outoms. show 6 and th tossd. first Copy Calulat is: rand-A. ar th wants at faulty rand-A oins a sltd attry of 6 diagram. rolling 4 Representation two and hav numr happns. 3 Th a th di, ths di ● numr an on th half of diagram? 1st ● hav for odd th possil sixs. die on two fair di. as an on wll. odd th 2nd S TAT I S T I C S 4 Nink a goal goal By 5 and on on hr Nink b nithr drawr grn rst rst drawing a A Mrl hr a Calulat b A andl th Mrl and 3 Y P(G) is A th Th Th alulat oth grn and ntall. 0.75. proaility proaility that that Nink Mrl will will sor sor a sor will and 2 vnt th a proaility goal sor a yllow piking on goal thir on rst thir andls. a that: G yllow is attmpt rst th attmpt. vnt piking a andl. P(Y). from sond th drawr. andl is Its thn olor is notd and it is rplad in pikd. Baus is a tr diagram to rprsnt th sampl still pik sond c Vrify two that yllow 1 Calulat 2 a you piking If you a If of b If of 4 you a pik you do not a a a pik piking Dtrmin a rd lu ard rd rd a a ard ard rd piking you tim. grn andls is mor likly than piking 3 rd pik a two proaility pik piking 3 th andls. th piking b andls from solving Exploration If 5 andl thr spa. to Problem th rplad, ar Draw P R O B A B I L I T Y 0.82. Mrl is pikd drawr. is will nor ontains a is diagram, Nink andl, play attmpt tr and oth attmpt A N D what th ard th and nxt ut ut from to a rd rpla ard it, from this alulat st. th proaility of tim. thn rpla it, alulat th proaility of tim. do from happns rpla thn nxt ard ard piking and ard ard lu rd th of not th do th th rpla it, rmaining not rpla rmaining alulat th proaility ards. it, alulat th proaility ards. proailitis for th sond vnt whn ard. 4.4 What are the chances? 14 5 Tr diagrams Hr ● ar With not two show typs ah of rplamnt hang for outom tr – th and its assoiatd proaility larly. diagram: ths sond Tip rprsnt situations whr th proaility dos Situations vnt. ‘with rplamnt’ produ ● Without rplamnt – ths rprsnt situations whr th proaility indpndnt hangs for th sond vnt. vnts; ‘without rplamnt’ Example ar A ag from ontains th vnts 4 ag 3 lmons and not and put 2 ak. lims. Thn A a pi sond of fruit pi is of pikd fruit is at dpndnt. random pikd at This is a ‘without random. rplamnt’ a Draw b Find a tr diagram P(Lmon, 1st a to rprsnt Lmon) and outoms P(Lim, 2nd pick th and thir proailitis. situation. Lim). pick 2 Lemon 4 The 3 upper arm probability Lemon of of the rst selecting a branch lemon; shows the the lower 5 arm 2 Lime represents selecting a lime. Since there 4 is no replacement, probabilities for the the rst pick second aects pick , as the you 3 Lemon can 4 see in the second set of arms. 2 Lime 5 1 Lime 4 b P(Lmon, P(Lim, Lmon) Lim) Example = = 5 ATL In a ox ar 3 rd pns, 4 lak pns and 2 grn pns. You pik a pn This at random and thn put it ak. Your frind thn piks on at is a ‘with random. replacement’ Calulat th proaility that you oth slt th sam olor pn. situation. R B G = = = hoosing hoosing hoosing a a a rd pn lak pn grn Dene the events. pn Continued 14 6 4 Representation on next page S TAT I S T I C S Friend’s A N D P R O B A B I L I T Y pick 3 Red 9 4 9 Blue 2 Your pick Red Green 9 3 3 9 Red 9 4 4 9 9 Blue Blue 2 Green 2 9 9 3 Red Green 9 4 9 Blue 2 Green 9 P (R, R) = Find P (B, B) the color P (G, probability G) pen, for each R) + P (B, B) + P (G, G) proaility Practice 1 A ag from a getting the three the same colors. that th oth slt th sam olor is P(R, R) + (R, P(B, B) R) + or (B, P(G, B) or (G, G) . 4 ontains Copy you of = is Th of = Probability P (R, for = ag and thr and at lal rd it. th ppprs You tr thn and four tak diagram grn anothr low to ppprs. tak a pppr pppr. show 2nd You all th proailitis. pick Red 1st pick 3 Red 7 Green 3 Red 6 Green Green b Calulat th proaility you at c Calulat th proaility you do d Calulat th proaility you at two not at rd at last ppprs. a rd on pppr. rd pppr. 4.4 What are the chances? 14 7 G) 2 A ag ontains 1 whit, 4 rd and 2 lu ountrs. Ros piks a ountr and In dos not rpla it. Sh thn piks anothr Q2, two a Draw a tr diagram to show all th 3 4 Calulat Thr oins a only b at c no d Explain piks a 9 two ar is proailitis. outoms: a sh tr piks 1 diagram whit and and 1 rd alulat and (whit, (rd, whit). ountr. th proaility that: rolld is rolld rolld. rlationship Th ards that Draw numrd and th rolld. Had th sid. Copy Find on ar on proaility Had Hads Thr on ar on last th ar possil rd) b thr ountr. ards othr from sid th omplt proaility twn on is a your tal, lank. answrs ah Th with ards to a ar b and c numr all 1 lank to sid 9 printd up. Srna st. this tr 2nd diagram. card odd that: odd 1st b oth c at ards last ar on card vn ard is even odd. odd 5 Of a will group of v sltd pikingnams studnts, for out a shool of a hat. two trip ‘Mary y th Th even v studnts Harryand a With Find th th aid Alix th has ox, Th a of Mary, tr Rafa, diagram or ominations proaility that Mary a of tal of studnts and outoms, that Pitronlla nd ould will go th numr of sltd. on th trip. solving ox of without tal a possil Problem 6 Jak, Pitronlla. dierent b ar shows rd, yllow and grn marls. Sh piks a marl from looking. th proailitis Color Probability red 0.4 yellow 0.25 of piking th dirnt olors. green a What b Thr c Alix d is ar piks Draw a What is 14 8 th 5 a tr th proaility yllow that marls marl, diagram thn to proaility Alix in piks th ox. rplas show that th at it in a grn How th marl? many ox and rd marls piks on of th marls is ar anothr. proailitis. last 4 Representation and Jak’ is even rd? thr? sam and as Mary’. ‘Jak S TAT I S T I C S Reect Compar and your discuss tr diagrams ● Did you all gt ● Did you all draw ● For Venn qustion a th do 3 for sam Prati 4, qustions 2, 3, 5 and 6 with othrs. answrs? sam you P R O B A B I L I T Y tr nd to diagrams? draw a ranh for ah olor? diagrams Example In 6, th A N D group 6 of 30 hildrn, 9 hildrn lik only vanilla i ram, 13 lik only Y ou strawrry i ram and 5 hildrn lik oth. Th rmaining hildrn an us diagrams not lik ithr Vnn do to rprsnt avor. information and thn alulat proailitis a Draw a Vnn b What is diagram to rprsnt this information. from th i liks ii dosn’t proaility strawrry lik i that a ram strawrry or hild ut pikd not at th diagram. random: vanilla vanilla? vanilla strawberr y a Draw 9 5 the Venn diagram. 13 Remember children to who include like the neither 3 avor. 3 b i P(liks ii P(dosn’t Practice 1 In strawrry a and not strawrry vanilla) or = vanilla) 5 group 7 lik ut of hoos a Draw a b What is ours 40 Vnn th ut popl, 35 hoos a main ours, 10 hoos a startr oth. diagram to proaility no rprsnt that a this prson information. pikd at random hooss a main startr? 4.4 What are the chances? 14 9 2 A group of vollyall 3 30 (V ) ar non of askd ths 3 hildrn do ● 2 hildrn play ● 6 play vollyall ● 3 play laross and asktall ● 6 play laross and vollyall ● 16 play asktall ● 12 play vollyall a Draw b Calulat A a not Vnn th play all any thr and diagram proaility vollyall ii plays only laross iii plays only vollyall. (R) and 90 and studnts Th thr wath of that in (T ). a wath tlvision, ● 20 studnts wath tlvision ● 18 studnts rad and go ● 10 studnts rad and wath ● 60 studnts a Draw Calulat th b only waths c only gos Problem Of 150 and 50 nw to to hild to sltd ut rsults and asktall (B ), go to inma 60 a this random: laross aout wr: go to th go to thir th fr-tim inma (C ), rad th inma inma only only only studnts display at wr: and tlvision that not hois rad th tlvision, proaility rad, 70 studnts go to th inma. information. studnt pikd at random: tlvision th inma. solving univrsity studnts study studnt sltd a only Arai b only Chins c nithr 15 0 (L), ar: information. qustionnair Th studnts diagram a popular 26 Vnn laross rsults sports this asktall ● a ths display lld most tlvision wath play Th sports to plays of thy asktall i group if sports. ● ativitis. 4 hildrn or at Arai studnts, oth random or 65 of thm languags. studis: Chins. 4 Representation study Calulat Arai, th 80 study proaility Chins, that a S TAT I S T I C S Two-way A two-way This 150 tal two-way rprsnts tal shows univrsity information th gndrs in and rows and dgr olumns. sujts of studnts. Science Ar ts Linguistics Male 40 18 33 Female 15 20 24 th P R O B A B I L I T Y tables rst-yar From A N D rows: From th columns: Thr ● Thr ar 91 mal ● studnts Thr ar 55 Sintists (40 + of (40 + 18 + Thr ar 59 fmal + 20 + Thr total of Thr a b th ar 57 studnts (91 + of + total 20) (33 + + 38 + tal of 150 studnts and th sujts Male 40 18 33 Female 15 20 24 proaility i is mal ii is ithr A fmal studnts totals olumn mal or studnt that a studis is pikd studnt hosn at thy b or adding totals. study: random: Sin. at random. Find th proaility that sh Arts. P(mal) male P(mal P(fmal, students. = Total ii of adding 57) Linguistics i – 24) 91 a numr 59) Ar ts studis ways th 7 two-way th Linguists 150 Science Find (18 row total (55 From Artists 24) 150 Example 38 studnts A A ar studnts ● (15 two alulating 33) ● ● ar 15) or studis studis Sin) Arts) = = 150 students. 91 males, plus 15 females studying Science makes 106. 59 female 20 study given that picked is now students Arts. at a Note female random, 59, not in total, that student the of since which it is sample is being space 150. 4.4 What are the chances? 1 51 Practice 1 Th 6 tal shows ustomrs’ mnu Miso-glazed hois Chicken in a rstaurant. stir-fr y Lamb kibbeh salmon Male 9 12 8 Female 1 14 6 From this th numr of mal b th numr of dinrs c th proaility a Complt aility b that alulat: dinrs who a in th rstaurant ordrd randomly hikn hosn a Th two-way tal to studnts wr atgorizd rprsnt Thr ● Half ● Thr wr 16 mal ● Thr wr 28 ginnrs in ● Thr wr 12 advand fmals. ● Thr wr 10 intrmdiat wr of tal or is studnts wr sltd an was hikn stir-fry for a this information aording to on gndr snowoarding (M/F) and sta in total. mal. at advand shows Under 40 is 60 thm studnt studnt Th dish (advand/intrmdiat/ginnr). ● A stir-fry dinr. groups. 3 tal a fmal 2 two-way ginnrs. total. studnts random. mal in Calulat total. th proaility prfrns for mid-morning drink, Coee Water 4 13 10 12 12 6 over this groupd Tea 40 that snowoardr. y ag. Calulat: a th prntag b th fration c th proaility undr 40 and Problem 4 A ● hoir has Thr of of sta sta undr who that drank a 40 drink watr randomly hosn of 51 ar th 4 mmrs mal in thr ag groups: undr-15s. undr-15s ar fmal. 3 ● 26 ● 7 fmals mals 15 2 mmr was solving 2 ● sta ta. ar and ovr 11 15. fmals ar ovr 4 Representation 20. undr 15, 15 to 20, and ovr 20. S TAT I S T I C S a Calulat i mal iii agd ovr Th D 15 ondutor What do ‘Choos fruit Dos you on has an a of qual mmr pikd at random is: th a mal soloist is soloist undr at random. Calulat th 15. that imagin th b Now, c Rpat Simulat n = tak 100, Th Count a th fair ah our Proailitis look many Ths you oin 10 of data a of of to an In in mak? th following proaility, T) Without and again rordd toss it 50 writ and 50 tims using a ral rsults Hads it sntn: mans atually it that ah pi tossing th oin, down. rord th rsult. outoms. rording thnology; is oin ar lt th th rsults. numr of tosss, and muh longst , so you a run st of of in Tails th in ah lngths of st run of in data. would numr of happning will thy Dtrmin xpt roughly half th rsults Had. numr what rsults. data. = th random dirn ah giv random. in vnt aus oin. or Hads is larg a oin oin thr data of a random w t. tossing run dsri random of 000 of th and P(Had) of in disions hosn. (H hav imaginary oin proaility would ing non-random st word tossing tossing numr st whih of ar whthr and th random’? outom tossing longst Stat random Th th your th data. In ral simulation Find in you rst until 1000, whthr For a th at han imagin this y fruit at 4 Prtnd 3 not hooss undrstand Nxt, 6 hoir 20 randomnss pi 2 5 to that Exploration 4 a Randomness ● 1 that 15 proaility of proaility P R O B A B I L I T Y fmal ii b th A N D of is th losst to proportion half of th rsults? tims th vnt trials. happn do Hads not in th show long th run. Somtims rgularity that vnts ours may aftr rptitions. idas proaility. rordth ‘rolling a lad If to you numr 6’. As th tak of th dirns a 6s, fair you numr di and an of twn roll it alulat trials xprimntal 100 th inrass, tims or and 1000 xprimntal this thortial tims and proaility proaility gts of losr to th 1 thortial proaility valu of 6 4.4 What are the chances? 15 3 Practice 1 Amlia 7 wants xprimnt. 2 to pik Whih a Piking th rst b Piking th last c Putting Jo, Amy Aftr did and v not idas of th roll a 5 5 Sam 6 at studnts ths to studnts of play Jo all a all. randomnss and a will th 6 gam Jo th hr a lass truly for a proaility random sltion? room. rgistr. into whr twi, thinks from nsur into studnts oard Sam random walk on th rolld at mthods studnts nams rounds, 5 of Amy and proaility to a hat, you nd rolld Amy and a 6 must xplain to 5 throw thr how piking a 6 tims, hating. ths out. to Us rsults start. and ar Sam th du to han. 3 Max ips a a Explain b H oin 10 tims whthr or and not gts this 7 Tails. shows his oin is iasd. Biasd kps ipping th oin and ounting th Tails. Th tal shows his rsults. Number Do 4 a you 52 500 265 1000 580 If and wins a Hadly and of if 3, Eliott throws a Draw a b Calulat tr i Ptr ii Eliott iii Ptr 15 4 a h h diagram th wins wins wins on on whthr his to this or wins; if outom. a If th sum wins Is sum multipl of if 4 th of thn if if thy oth rolld a two is odd. fair? di Morgan is a wins. 6. h h throws throws this a a Tail, Tail it it is is gam. turn turn. think 4 Representation this is a fair Eliott’s Ptr’s turn you sors. sum gam th that: third thir th gam. rprsnt rst not is thn fair. oin wins; rst his a th ruls. it di, Morgan again. happn proaility on is answr. 6-sidd and th If roll gam Had a your rprsnt playing Had roll vn, wins. would ar a to thy this what is Justify hang Hadly Suggst throws ah spa if fair? sum multipl, ii Disuss th Morgan Dtrmin Ptr is Morgan i and oin sampl nithr Eliott c th Hadly Ptr of Tails 100 multipl 5 Number 24 Hadly If ips 50 think Draw b of gam. turn. turn. If mans unfair. S TAT I S T I C S Reect Dsign a ● ah ● on and gam for playr playr discuss two has has an a gratr P R O B A B I L I T Y 4 playrs qual A N D using han han di, of of oins or spinnrs, so that: winning winning. Summary Th sampl spa thomplt an st xprimnt. S, of It is all an a rprsntation possil a of outoms list, a tal or P(A) from rprsnts P(A′) is th th proaility proaility of A of not vnt A ourring. ouring. a P(A) + P(A′) = 1 diagram. Th A singl event is a sust of th possil proaility proportion listd in th sampl 1 Miloš is taking On two systm failing numr two ours grads) of A, summr B, grad). is ‘pass/fail’ whil C, F lasss th (with Assum othr F that th (thos has ing th at a th loal ar 3 th At th of ours is shool 12 ans grading rahs only and proaility of vnt th happning vnt would is th our in a trials. for Write b Use th your and th hr on 10 oolr frind of ans to th of gra oolrs soda. a ontains Rhona drink for hrslf Maro. of a tr diagram and calculate th qual. proaility a pini, jui into on Draw ah an tims practice ollg. only of spa. larg Mixed of outoms sampl spa diagrams to as a nd list th and as a tal. proaility that: a sh gras two juis b sh gras two drinks that ar th c sh gras two drinks that ar dirnt d nithr sam that: i Miloš passs oth lasss ii Miloš passs xatly on 4 lass Olivia On iii Miloš fails oth Thr ar andO. a four Ths Rhsus Write ar fator, Forxampl, a main th lood paird whih your with is lood sampl typs: B, AB somthing ithr typ spa A, for ‘+’ or ould th ‘ 6. alld that ar othr By all lood proaility b typ typs that AB di O d a lood e a ‘positiv’ has of or othrwis: di sids at th and sam thr tim. lak a Find a th tr sids numrd diagram, tal from sids. of 1 how many dirnt dirnt ominations sh an possil roll. Calculate proaility lood ar you qually likly, what is th c th d an Calculate rd hav: and or vn that sh will roll a th that sh will roll a lak Calculate proaility and th lss that sh will roll a numr. a 5. proaility than 2. lood typ to outoms B+ numr typ rd jui. possil. lood c 6-sidd thr mans rd If two has a ’. b typs rolls di gts lasss. Th 2 prson othr lood than A or B typ? 4.4 What are the chances? 15 5 5 Ann has a whistls ag and ontaining 1 grn 3 lu whistls, 4 rd b Calculate whistl. from Simon 3rd Th Ann has a ag ontaining 2 lu whistls 8 ar hooss a idntial whistl at xpt random for th from olor. hooss a whistl at random hr from ag Rpat Q7, Calculate Draw a tr diagram information ofah of and th to write vnts rprsnt down on th A typial of of 120 ut how this th tnagr tim th itm proailitis should 2000 studnts, rvald proaility ranhs takn is rplad. hang. onsum th aloris thr-fths pr of day. whih A survy wr mal, following: th ● tr on ar hisag. this th that alulator ag. approximatly a on and 9 Simon th proaility and and whistls. whistls th protrator 80 studnts at mor than th rommndd diagram. amount. b Calculate th proaility that oth Ann and ● Simon will hoos a lu Half of th girls rommndd c Calculate hosn th y proaility Ann will a hosn y that th whistl dirnt olor to A rnt high study amounts of of ● sugar and 6 th Fiv-sixths of th oys at mor than th amount. Simon. 24 sodas ain, rvald 12 hav that high 8 hav hav Th sam numr rommndd of oys amount of as girls at th aloris. amounts a of than th ● 6 lss amount. rommndd on at whistl. Complt a two-way tal to rprsnt this oth. information. a Draw a Vnn diagram to rprsnt this Calculate th proaility that a studnt sltd information. What is random th proaility from th group b is high in sugar ut c is high in ain d is not that in not a soda th in pikd at random: b at c is at th rommndd amount of aloris study: mal and at lss than th rommndd ain amount only d 7 A ag high ontains protrators at random takn in at four (P ). and ain itm is replaced. (C takn A at mor givn sugar? alulators On not or ) and from sond six th itm random. 10 ag is thn In a th group rst holstrol prssur Complt th proailitis tr in diagram th spas y C P C P P 4 Representation popl, oth; 28 that high 23 hav a amount fmal. 10 ar lood popl high prson halthy and prssur, hav high holstrol. sltd at high lood Find th random: writing providd. C 15 6 50 rommndd ar ithr or and th thy of hav proaility a than that a has high lood prssur b has high lood prssur and c has high lood prssur or d has high holstrol only. high high holstrol holstrol S TAT I S T I C S Review in A N D P R O B A B I L I T Y context Identities and relationships Problem on solving if 1 Th hart diats valus. shows for th risk dirnt BMI is a of ody way of dvloping mass indx masuring Typ fat in th ody. For adults, a th (gn) parnts 18.5 and ar would riv ah MM and parnt. Mm, For thn instan, ‘M’ ‘m’ an ‘M’ from th rst th hild parnt and an (BMI) th or from th sond. amount halthy BMI Copy and omplt th sampl spa for th is dirnt twn from 2 a of alll outoms. 25. 100 Mother 93.2 gnipoleved MM 80 fo setebaid M Mm M M mm m m m 60 54.0 ytilibaborP 2 M 40.3 epyT 40 MM 27.6 M 20 15.8 8.1 1.0 5.0 4.3 2.9 M 0 5 3 ≥ 3 . 4 9 9 3 . 2 3 . 0 9 9 2 . 8 2 . 6 9 2 . 4 9 9 2 > 2 . 2 1 . 0 9 9 Father Mm - - - - - - - - 3 3 3 1 2 9 2 7 2 5 2 3 2 1 1 9 m 2 Body mass index (kg/m ) m a An adult has BMI 28. What is thir risk of mm dvloping Typ 2 diats? m b Describe hangs how as th BMI risk of dvloping diats b inrass. If a hild inhrit c An adult has BMI 31. H loss wight BMI risk of 26. Typ How 2 many diats tims smallr is orn Write som dvloping to 2 justify Vinnt his Typ your knows hildrn family. advi for c 2 diats. th Use risk that thr h a Calculate proailitis has is a 15% thr han that runs hildrn. of in Find d his all b at of his two of hildrn having th his Proaility liklihood that of his hildrn having hildrn having th an of usd hildrn in gntis inhriting a hav th th proaility gn that th hild will (m). parnts, oth of whom ar Mm, th proaility myopia that th rst that only that nithr hild (mm). th proaility on hild myopia. Calculate th proaility hild disas hav myopia. disas. to prdit ondition th Determine hav to whih hav in gns ordr for th th parnts would proaility that 1 from thir rst hild has myopia to 2 thir parnts. rprsntd (myopia) is Suppos y ‘M’ th whil rprsntd Reect and How you hav gn that y for of ‘m’. normal short sight is sightdnss Ahild inhrits discuss xplord th statmnt of inquiry? Giv spi xampls. Statement of Inquiry: Undrstanding using a disas g 3 hav Calculate will non proaility myopia. th f c hav of: thr last thy hildrn. Calculate will a will myopia two two will e proaility th Suppos hav disas th whn of ommnts. inhriting Suppos rduing alulat only his now? arry d ‘mm’, myopia and hild has inhrits logial halth and making rprsntations and halthir hois rsult from systms. 4.4 What are the chances? 157 5 Simplication The process of reducing to a less complicated form go Programming to pen In computer x: programming, a block is a section of code grouped together. down ▼ Experienced programmers write code in direction for at least three reasons: each block can it makes it simpler for others 4 to move understand, perform just one simple task, the act of is made working simpler. through (The a term ‘debugging’ computer program here errors that cause the program to fail or to identify give degrees 90 means and pen remove steps 320 and turn debugging 90 in repeat blocks -160 that point is y: -160 code up incorrect to results. It is much easier to do this when the code has been to written in blocks that can be tested independently.) ▼ point Get a code part sheet here of a of graph written graphic paper using ‘proof’ and see Scratch of the is if you gure designed innite to series out do. sum what The the result below, is in repeat go to direction 8 will learn about in IB DP q x: 4 down n move 1 1 + 2 + 4 8 + ... = 16 go Scratch is developed by the Lifelong Kindergarten Group at the MIT Media Lab. See http://scratch.mit.edu Smar tphones replaced a camera, clock, ● the a (and need the for laptop, applications other diary, devices maps, that and run on them) equipment, ashlight, have such calendar, alarm,etc. Suggest our made 15 8 some lives, life but ways also more that smartphones suggest some complicated. up 1 to turn Smartphones steps 1 pen + q Mathematics. pen 1 y: which repeat you 90 ways have that simplied they’ve as: q x: 90 set to set to y: q degrees Simplied In the writing making the literacy, learn, of Chinese the written simplied because characters The table and three to it a Chinese language Chinese has fewer Roman here shows hard was to many learn. introduced. strokes script, the language, per based Pinyin, on traditional Beginning Simplied character. in characters 1949, Chinese Pinyin is the in is are an very effort probably conversion complex, to increase easier of Chinese pronunciation. Simplied and Traditional characters for three Simplied Traditional character(s) character(s) 数学 數學 Pinyin Mathematics shù To count shù 数 數 To learn xué 学 學 书 書 马 馬 谢 謝 thank The of rst xiè near one of a the the village Beijing, of xué character Cuandixia, name nouns verbs. English To to is most complicated traditional characters, up of 30 Chinese made strokes. 15 9 Are you saying I’m irrational? 5.1 Objectives ● Simplifying Inquiry irrational numerical ● expressions F MROF ● Approximating ● Applying ● Performing rules expressions questions What is the and ● What a ● How do ● How are an between irrational a rational number? radicals of radicals operations that on contain to simplify radicals to is radical (surd)? them you approximate a radical? simplify radicals C the ● rules How is the for ● D Can rules radicals related terms radicals in to algebra? similar to fractions? irrational form of combining simplifying simplifying ATL dierence number rational numbers be combined to numbers? Communication Draw reasonable conclusions and generalizations 5.1 10.3 E5.1 Conceptual understanding: Forms can 16 0 be changed through simplication. N U M B E R Y ou ● should identify already radicals and know how understand to: 1 Simplify each expression. Muhmm what they in represent a 9 + 16 b 9 + 16 Mus (. c 3 × 3 d 11÷ l-Khwrizmi 780–. 850 ad) 11 rfrr to rtionl 1 e 3 × 6 × 8 numrs f s audible, 9 n irrtionl numrs s inaudible. Reviewing F radicals l ● Wht is th irn twn rtionl numr n to th ‘ ’ Wht ● How is o (smm, numr? mning ● ril you (sur)? or pproximt ‘f ’ ‘um’) irrtionl ril? whih square root (lso known s radical or surd ) of positiv numr x is ws Any Th of In x, whih, positiv gnrl, For numr principal n is square writtn ‘th writtn Hr r som = 5, π 1 hr itslf, squr givs roots: positiv th on originl positiv numr x is th numr n on positive s ‘surus’. x. ngtiv. squr root . ut mns th th squr 25 s of positive root of squr 25 n root. lso 5. This is 5 wht 7.262626… r th of y 1 som w ll of wht twn numrs’: 18.2 w 17.41002368… irns ‘rtionl 3 xmpls 2.39841… Stt two root xmpls 1.45 An hs root’ own Exploration multipli s squr 25 xmpl, normlly whn thn into Ltin numr for numr, trnslt A ltr Ari n wor irrtionl This (surds) ll ‘irrtionl numrs’: 0.83126674… ‘rtionl numr’ n n ‘irrtionl your rsoning. numr’. 2 Dn 3 How A h woul rational of thm you in your lssify number is own wors. numr numr tht lik n ? Explin writtn s frtion whr W hv nms n . For xmpl: 1.2, −0.3, n 0 r fw irrational spil irrtionls, numrs. π, An number is numr tht nnot writtn s ϕ, n imls. numrs n cannot π r rprsnt xmpls of s trminting irrtionl or lik Eulr’s frtion. numr, Irrtionl only ll rtionl givn to . rpting numrs. 5.1 Are you saying I’m irrational? 1 61 Hr ● r Th squr thir r ● som importnt roots vlus r rtionl Th squr numrs of fts out positiv whol squr squr numrs. roots: numrs 4 = 2, r rtionl = 5, 25 numrs = 10 , 100 n us 2025 = 45 Tip numrs. roots 2 , of positiv 247 24 , non-squr n r 1000 numrs r irrtionl irrtionl. us thir Th trms n ‘sur’ writtn s frtion. A ril (or sur) is nothr wor for to rfr root of numr tht hs n irrtionl Som irrtionl squr root, numrs yt thy r (suh still π, s for irrtionl xmpl) n’t writtn s numrs. You ithr oth) my wor us and ● Try to ● Is possil it n discuss th to vlu tk in ooks. 1 of th s (or mthmtis Reect n squr vlu. root. ● oth to th irrtionl squr r vlus us nnot ‘ril’ Th . squr root of ngtiv numr? If not, why not? ATL Exploration In this For 1 xplortion, th In 2 purpos opy of of this you will this xplortion, tl, stimt omplt = squr you th n vlus root without ignor of just using ngtiv the lultor. squr rational squr roots. roots. Tip = 1, 4, th 9, n rst fw numrs. 2 Look t th n vnly 3 , sp Squr your Commnt stimt 4 Rpt 3 n squr 6 Using 16 2 1 th th your roots 1 tht r r similr still lnk. of 1 n stimt from your n 2. th stp 2 r Assuming vlus using stimts. in tht of twn thy n r . lultor. Cn you n ttr pl? roots ll vnly tht squr vnly or 2, vlus of rsoning, 5 Simplication in 2 n twn stimt 3, n pirs th of twn onsutiv vlu of h on. lultor. stimts. giv squr suggst twn n using your sp lrg r roots sp, vlus ury roots r twn n ury squr th tht oth stimt on squr r iml Assum Commnt roots twn numrs Squr smll thy stimt on to for 4. whol 5 squr so you mor Dos ssuming urt tht stimts th for roots? mtho for stimting ny squr root. 16 r squr N U M B E R Practice 1 Without of 2 ths 1 using writ own or stimt th squr 121 b 64 c 15 d 12 e 27 f 50 using lultor, stimt th vlu of th prinipl a 24 b 55 c 82 d 90 e 56 f 99 Problem By ths is 2 lss vlus thn 15 (<) of or 8 irrtionl, iml. you th 11 7 d of h squr roots. ny rils grtr thn or othrwis, (>), shoul trmin rpl th whih to omplt sttmnts. 7 a roots solving stimting inqulity, if lultor, a Without 3 numrs. A so it nnot lultor 2 wrot n orrt to b 3 + e 5 × 5 3 4 rprsnt pproximt lrg c 38 2 numr × y to of 6 23 4 f trminting iml, iml × 50 s it 10 25 + iml suh pls, 1+ or rurring 1.41421356. oul only 15 Evn vr Numrs n n pproximtion. Th only wy to writ th exact vlu of th squr root of lik 2 rprsnt is s trminting 4 2. Unlik th iml form of, for xmpl, = 0.363636... whih is iml, in this 11 rurring, th iml form of 2 os notrur. s 0.375. numrs Hippsus irrtionl intgrs of Mtpontum, numrs. (i.. s H followr show rtionl of tht numr), Pythgors, nnot n tht is si writtn thrfor it to s hv th must isovr rtio of n s two isovry muh to tht h of th irrtionl sntn numrs Hippsus to upst th y n trri rowning t Pythgors s s rprsnt rurring s This suh imls, irrtionl. Othr in innit this 0.26666666… so (oring lgn). Exploration Consir th 3 following list of numrs: Tip 1 Without using lultor, orr th numrs from smllst to lrgst. Your strtgy involv 2 Us lultor 3 Suggst to hk your nswr. nomintors strtgy tht osn’t involv using lultor to ompr: squring Dos a b frtion ril to to whol whol numr lwys om numr whn squr ril to n numrs. numr lrgr c oul ommon you it? frtion. Continued on next page 5.1 Are you saying I’m irrational? 16 3 4 Without pirs of using lultor, numrs. a Rpl 5 d Reect and discuss us your th y strtgis <, > or to ompr th following = b c e f 6 Th 2 squr sign, Th only wy to writ th exact vlu of ril numr is y root ll ril sign. sign. Any ● is using th th , Wht ny r th possil vntgs of using suh nottion for rils? Ar thr trm it isvntgs? is numr or unrnth ll th rin. ● How n os this xprssion irntly whn pproximt How C ● t to thy How r How in is th ril r wy you prform numrs? writtn using Do th oprtions rils sign on hv thn whn thy r iml? radicals trms ● nottion ontining th ruls behave of rils rlt to th ruls for omining lgr? simplifying rils similr to simplifying frtions? Aoring to th ATL Exploration Ntionl 4 n You r going to xplor th thr si ruls of Oni Atmosphri rils. Aministrtion, Rule sp 1 pr 1 Evlut ths s a b c d e f son) (in gnrl rul from wht you foun in stp 1 th pth mtrs) on, th th = , 2 whr 3 s d of using formul Rule t tsunami movs is trmin y Du th mtrs mounts. whih 2 (in Us lultor to vlut ths mounts. g (th lrtion u to 2 grvity) 4 a b c d e f Du gnrl rul from wht you foun in stp 3 Continued 16 4 5 Simplication on next page is 9.8 m/s N U M B E R Rule 5 6 Th n 3 Us lultor vlut ths ril xprssions. a b c d e f Du ruls of gnrl rils iviing Example a to rul tht from you wht you isovr foun in in stp 5 Explortion 4 rlt to multiplying rils. 1 Simplify b Simplify a When multiplying, the order doesn’t matter (associative property). (Rule 2) Leave the nal answer without the × sign. b Rewrite a division as a fraction. Recall the rules of fractions: (Rule 3) Rules For of ny Rule 1 radicals rl numrs Rule : 2 Rule 3 b ≠ 0 5.1 Are you saying I’m irrational? 16 5 Practice 1 Simplify 2 h xprssion. 18 26 a × 5 3 b 21 × 21 5 7 c × 11 d 2 3 5 42 e Fill in th × 2 35 g h 6 Problem 2 12 f 75 4 20 × 8 solving lnk 18 to mk th xprssions qul. 6 = 9 3 × ATL Exploration 1 Simplify 2 Whn th 5 frtion frtion is . qul to 1, trmin wht this tlls you out th numrtor n th nomintor. 3 Hn, writ own (s n qulity) wht you n u from . h 1 4 Using th 5 Suppos Pythgorn thorm, n th hypotnus of this tringl. 1 lrgr you lign right-ngl thr tringl suh lik tringls long th hypotnus h 1 h h 1 3 1 1 h h 1 1 1 Writ own 6 Now, using 7 Wht n n xprssion th you and sm for tringl, u from discuss 1 th us th lngth th of th hypotnus Pythgorn prvious two stps? your nings 3 of thorm Drw this to lrgr n th rsonl 3 √ in stp 3 to Explortion 5. 2 1 your 18 nings in stp 7 of 1 Ar ● thy How quivlnt? os this igrm 3 illustrt your nings? √ 2 1 1 √ 1 1 3 16 6 nw, h 1 Compr 1 1 ● mk this: 1 Reect to 5 Simplication 2 tringl. lngth of th onlusion hypotnus. or gnrliztion. N U M B E R In Explortion simplies 5, to you Exploration Blow r foun tht som rils 1 Explin th 2 Explin how 3 Dtrmin in form most 4 will th Explin Explortion Example Method pross how 6 illustrt Simplify A wy of sying this is tht 18 6 n thir Unsimplied is 18 . = . you for mny you n Simplied simplify wys you form. form ril. . n nswr qustion 2. Stt whih simpli. know monstrt it form simplifying woul how simpli whn on irnt ril mtho of can simpli. simplifying rils. Exmpl 2 mtho. 2 . 1: 9 is a square number factor of 18. (Rule 2) Write Method the nal answer without the × sign. 2: The prime factorization of 18 is 2 × 3 × 3. (Rule 2) (Rule 1) 5.1 Are you saying I’m irrational? 167 Reect ● Whn is ● it and simplifying importnt squr root Compr r ● discuss th y is Somtims Example squr root ftors using ftors mthos using tht r tht us r in Mtho squr not 1 from Exmpl numrs? squr Exmpl 2. Cn you 2, why simplify numrs? Woul you sy tht thy mthos? simplifying th Dtrmin n two quivlnt How to 4 squr rils root lik nnot simplifying frtions? simpli. 3 whthr or not a ths rils n simpli. b c 15 has factors 1, 3, 5, and 15. a Only You could However, No, nnot rewrite 3 and 5 15 1 as are is a not a square product square factor. of 3and 5. numbers. simpli. 45 has factors 1, 3, 5, 9, 15 and 45. b 9 Ys, n is the largest square factor. simpli. 30 has factors 1, 2, 3, 5, 6, c Only No, nnot Thr r two simpli situtions whn squr ● th squr root of prim ● th squr root of omposit thn Th 1 nnot onition squr ftor Practice Exprss to root numr nnot nnot numr tht simpli: simpli hs no squr ftors othr thn squr root is tht th numr hs t lst on 1). 3 h ril in its simplst form. 1 24 2 32 3 72 4 6 960 7 675 8 864 9 16 8 simpli. simplify (othr 1 5 Simplication 125 991 5 10 135 992 is a square factor. 10, 15, 30. N U M B E R Problem solving 4 6 99 a 11 200b 12 8 2 c 288 x 13 3 y ATL Exploration A 7 vinculum horizontl Whn ing n sutrting rils, th sm ruls pply s whn ing or sutrting whol numrs, frtions or Writ n a own thn h n Thr th twos of th following sttmnts in vrils. mthmtil nottion, four for grouping things togthr. nswr. plus twos mks In twos. 1637, Rné Dsrts b Two sixths plus thr sixths mks Fiv x’s d Thr plus six x’s to sign squr roots of two plus v squr roots of squr roots of with Writ own nottion h n of th trmin thy xprssions n furthr using mthmtil w ril us Thr b On c Six d Two twos plus four rt symol toy. simpli. S a to two. following if th two th 2 th ril vinulum mks th omin Grmn x’s. mks ws sixths. rst c us mthmtil nottion 1 you in r is lin to vs. how it is us istinguish from 3 Bs thir x’s plus plus v squr on thr stps y’s. roots 1 qurtrs. of n two 2, plus u two squr rul for roots ing of thr. n sutrting squrroots. 4 Compr thy 5 Simplify a n similr h Without ontrst n of in ths using ths wht four wys four xprssions. r thy Stt in wht wys r irnt. xprssions. lultor, trmin whih of th xprssions rqul. b Us c Of your th lultor xprssions itssimplst 6 Eh Du of ths rul to vrify tht r your qul, nswr. suggst whih on is writtn in form. xprssions for hs n ing/sutrting simpli. ril xprssions. 5.1 Are you saying I’m irrational? 16 9 You th ● n 2a (2 ● sm + + 2a 3a Th n 3)a + hv 3b or sutrt For simpli ommon is tru ● 2 5 + 3 ● 2 5 5 + 3 Example two numrs only whn you r ing multipls of xmpl: to 5a, sin a n ftor out to giv 5a nnot no sm Whr or mount. for = 5 7 simpli ftors. squr sin Thus, a 2a n + 3b b r is not writtn lik in trms, its tht simplest is, a n b form roots: 5 nnot simpli. 4 possil, simplify a ths xprssions b tht involv squr c roots. d a Just b Convert to like equivalent 4x + 2x square = roots. Simplify Substitute Adding only There c for terms when are no involving they like in have terms, the square the so original same this is . expression. roots is square the 6x possible root. simplest form. The largest square factor of 48 is 16. The largest square factor of 32 is 16. d This Reect ● How ● In and os prt d discuss simplition of Exmpl 4, 5 hlp why you is it or ttr sutrt to unlik rils? simplify to ? ● How is ing sutrting ● How 17 0 is n sutrting squr roots similr to ing n polynomils? simplifying squr roots 5 Simplication similr to simplifying frtions? cannot be simplied any further. N U M B E R Rule 4 of For radicals : Similrly, you Practice Simplify 1 7 3 12 9 lso sutrt rils th sm wy: xprssions. 3 a + 3 in 4 ths 3 n 17 2 − 9 a + 3 4 2 6 2 + 16 pq 17 + 4 pq Th 27 5 12 12 + prio sons 7 2 75 54 9 5 − 27 20 + 45 Problem 8 + 8 − 24 12 10 128 + + T in 48 32 + 48 + 18 75 + 162 of simpl pnulum of L in givn T = ft is lngth . solving 2 11 4 12 x + 3 27 x 3x 12 48 3 13 27 x Anothr 3x wy Reect Until to you nomintor You n Thr is think r numr simplify and now, two of 2 14 discuss hv s 1 possil iml (rtionl pls tht ÷ rpt ● How iult is ● How iult woul to or of th ivi 10 innit thos y to frtions s iml n n with s (irrtionl it rtionliz suh n typs pls it 4 to lt numr, numrs), on’t is + 8 y − 5 9x + 18 y nomintor. 6 proly whol of rpt rils 4 x or ÷ whr th . 3. numrs: numr with only n thos of with iml innit nit pls numr of tht iml numrs). rtionl ivi y numrs? n irrtionl numr? 5.1 Are you saying I’m irrational? 171 y Exploration Consir th frtion 1 Dsri 2 Simplify 3 Dtrmin 4 Simplify 5 Compr this 8 th . mount tht this frtion rprsnts. . Tip whthr × is qul to . For × 4, us th rul your frtion stp nswr to . Is it now sir to sri th mount tht rprsnts? ATL Reect ● and Prforming hs n rtionl nomintor. ● oprtion Is this rtionlizing If xplin so, 5 b of > 7 so nomintor Dos Rule For discuss tht similr th frtion inst to is simplifying nomintor with known s n mk it ril in th rtionlizing irrtionl sir to nomintor th numr? ompr numrs? why . radicals 0: Example 5 Simplify: a b a To b 17 2 5 Simplication simplify multiply by N U M B E R Somtims, ● Simplify ● Us you th n 3: Rtionliz Example th n mthos th to simplify nomintor ril xprssions: sprtly a to = b ● irnt numrtor a Rul us simplify th frtion b nomintor 6 Simplify: a b a Simplify the denominator Rationalize Simplify the numerator the and and cancel. denominator. denominator b separately, Practice Simplify th then cancel. 5 following nomintor in your xprssions. nl Thr shoul 45 40 1 in th 6 7 5 12 14 10 45 11 12 18 28 27 2 8 2 5 9 8 10 6 3 1 4 3 25 15 Problem ril 3 5 9 no 1 2 10 5 nswr. 150 solving 3 3 xy 108 x 13 15 3 3x 8 5 14 15 x y 16 10 xy 32 x 5.1 Are you saying I’m irrational? 17 3 D How ● Cn Irrtionl of radicals irrtionl numrs Pythgors. ook The B: Dsri To are nd a Euli isovr it wsn’t prov Invstigting pttr ns general similar. consistent wr th omin roun until to 520 roun xistn of form bce, 300 rtionl uring bce tht irrtionl th numrs? tim th Grk numrs in his Elements. Objective ii. numrs Howvr, mthmtiin behave If rule, the with s rule your pttr ns gnrl make sure applies r uls that only to onsistnt the rule some with applies specic to cases nings all the but specic not others, cases then which it is not ndings. Exploration Som 9 irrtionl numrs Som (ut not ll) squr roots r irrtionl ntur is π irrtionl (= n is Hr is list of irrtionl in numrs: of s (= 2.718…) pirs suh trms r thir sum is rtionl b thir sum is irrtionl c thir prout is rtionl d thir prout is irrtionl. Suggst vlus th lngth a its primtr is rtionl b its primtr is irrtionl c oth its primtr Dtrmin 3 for Th r Grk tims lttr rltionship. Th Goln musi, ll simpli thr Th if rtio pinting, 1 74 ths form r its r is is pprs ϕ is not just sign in n 5 Simplication is rtngl suh tht: irrtionl is rtionl irrtionl. r possil. Explin to th givn of r . ttr rprsnts of ntur, its n r of (ϕ) vlu n with omintions whn phi Th n n us whthr thn ‘Goln y: Justify or your not nswr. you think . rtio’, gomtri ϕ mthmtis, mny othr ut rs. in rhittur, rils. prt numrs of st known trnsnntl tht: a xprss of numrs. 2 in s rtionl Thy Fin suh 3.14159…) nnot 1 foun numrs: N U M B E R Summary ● A of square root positiv (lso known numr x is s radical numr or surd) Rules For whn multipli numr roots: ● Th x is A Any on th itslf, positiv positiv principal s ● x. y n square positive squr givs th numr on of radicals whih, ny rl numrs rational s number c ≥ 0: hs two squr Rule 1 Rule 2 Rule 3 Rule 4 ngtiv. root of root of x, is frtion positiv n is numr b ≠ 0 writtn numr tht n whr For c xmpl, n n 0 r ll 1.2, rtionl irrational writtn nnot rpting s , Mixed Compr y is frtion. rprsnt numr Irrtionl s imls. irrtionl n lso sm wy: For > sutrt rils in th numrs. number 0: . Rule An ≥ You For of b, . writtn ● a, originl tht b 0: numrs trminting n 5 nnot (pi) or r xmpls numrs. practice th following using <, > or pirs of vlus n Simplify rpl to = ths rtionliz xprssions th ompltly. nomintor whn Rmmr nssry. 9 1 20 2 13 12 14 15 125 16 17 10 19 xy 18 6 3 6 3 4 7 6 Without using lultor, estimate th vlu × 360 prinipl squr roots orrt to 18 3 × 12 of 3 th 121x 7 1.p. 98 5 × x y 20 2 45 5 6 6 15 17 21 22 24 3x 54 7 8 12 10 23 Rtionliz th nomintor for h 24 12 13 2 13 12 ril xprssion: 1 25 5 27 2 8 3 50 26 6 4 x + 3 9x 6 10 9 2 20t + 4 45t 3 28 3 200 a + 128a − 8a 15 11 12 4 8 75 Reect and How hv you Giv spi discuss xplor th sttmnt of onptul unrstning? xmpls. Conceptual understanding: Forms n hng through simplition. 5.1 Are you saying I’m irrational? 175 6 Quantity An amount or number How many Suppose of sh this? all not the want lake. could dead accurate One a You the and you in know the that but it’s estimate 100 sh, tag release them back that these sh all evenly Later, that, and you of 5 previously. You tagged in sh batches of capture all you’d then batches. 2000 5 100 there sh in are the the sh an and either! is called then Assume themselves again that that So how you to per If for and batch lake. nd tagged are 100 many need you to assume every catch estimated the you there sh? sh have sh lake. sh would tagged an practical, quantity ones tagged would At 100 lake. sh 100 catch you mean 100 count you throughout know the the distribute are give about method: into capture go and very them, randomly these, of the capture-recapture Capture not quantity you lake would considerate to the would drain count, way to How sh; too sh? 100, 100/5 that 20 × = 20 would 100 = lake. ● How in many the lake sh if would you you estimate recaptured 11 are tagged sh? ● ● What are being made What none the in assumptions this conclusion(s) of tagged? 17 6 all the sh that are method? could you you caught draw later on if were Skating In the by Olympics, gure skating single number complicated numbers how do routines from than the boil each you complex down judge? might to It’s The just a nal which more think. score is randomly awarded by 7 7scores, the accumulate points in a to prevent competition and judges also to from make the 9 highest and using the the computer scores judges. and a Of lowest those scores remaining 5 system areadded designed selects of aredisregarded Skaters tallied xing scoring up for the nal score. a less subjective. First, skaters move they get a basic execute, score for regardless every of how its executed. The judges this basic then score, add to based or on subtract how from well it was performed. Skaters are transition, skating it execution, hot possible Scoville The to give various Bell heat a on choreography, interpretation and a is the Bell a a of to diluted trained naturally of scale method then good types hot? create and peppers is to panel method does is devised isdissolved given judged skills. How Is also barely Carolina do in just a of In that.In 1912, who rate given amount the scale, sugar the that the American Scoville’s solutionof imprecise, of it is method, water. heat level based heat pharmacist (and driedpepper Varying in on concentrations Scoville human pain!) Wilbur are HeatUnits. subjectivity, experienced but when it eating peppers. register Reaper, on weighing pepper 0 spiciness? tasters estimation chili of Bird’s 100 000 – in with at eye 350 a 2.2 rating million Red 000 of 000 The Scoville Savina 350 0. – current 000 of units. habanero 580 champion Ghost over 1 pepper 000 000 17 7 Can I exchange this please? 6.1 Global context: Objectives ● Converting Globalization Inquiry between dierent currencies and sustainability questions ● Why ● What ● When do we need to convert currencies? F ● Recognizing ● Solving ● conversions word problems SPIHSNOITA LER Understanding and the commission in real-life involving meaning of contexts Calculating ATL exchange rate? dierent C rates are currencies quantities in dierent equivalent? charges commission Information Access an currencies ● ● is information charges How do systems inuence communities? D literacy to be informed and inform others 6.1 7.1 Statement of Inquiry: Quantities and measurements illustrate the relationships between 7.2 human-made 17 8 systems and communities. N U M B E R Y ou ● should calculate already the know percentage of how an 1 amount to: Find: a c ● calculate percentage change 2 25% 20% of of 386 78 kg Ω b 1% of 83 mm d 8% of 75 liters The cost of a package of noodles increases from $1.75 to $2.15. What is the percentage increase in cost? Introduction F ● Why ● do What is we an need to to currency convert exchange conversion currencies? The rate? of The number of people travelling around ocial monetary the world is constantly a country there is currencies no to Example Convert single global understand currency, the you purchasing need power to of be a able to convert particular is increasing. called As standard the currency between currency. 1 1500 Swiss 1 CHF = 1.20 EUR. 1 CHF = 1.20 EUR Francs (CHF) into Euros (EUR). The exchange rate is Write out the exchange rate. Method 1: Think: ‘What mathematical operation do I 1500 × 1 CHF = 1500 × 1.20 = 1800 EUR EUR need to perform to get from 1 to 1500?’ Multiply both sides by 1500. Method 2: Multiply by the exchange rate as a 1500 CHF fraction, to cancel the Swiss Francs. Example Convert 2 800 Euros into Swiss Francs. The exchange rate is 1 CHF = 1.20 EUR. Method 1: 1 CHF = 1.20 CHF = 1 CHF ⇒ 800 EUR = = EUR EUR 800 666.67 EUR Write out the exchange rate. Express the exchange rate in terms of Euros. Multiply both sides by 800. CHF Method 2: Multiply by an equivalent fraction. 6.1 Can I exchange this please? 17 9 Reect and discuss In 1 Switzerland, the ● Divide both sides of 1 CHF = 1.20 EUR by 1.20. What have you is ● What do your results mean in the context of currency smallest 0.05 for exchange? of a CHF, rate terms of of exchange, another Objective: ii. apply In this A. the Knowing selected practice or set exchange rate, gives the value of one currency in currency. 666.67 you and understanding mathematics will use the successfully skill of when converting solving currencies to problems solve the following problems. Practice 1 1 US 2 1 CHF 3 Dollar = 1.02 = 0.90 Euros (EUR). 1200 CHF into USD. b Convert 1734 USD into CHF. The exchange a is You 1 Using The to will the table from = 0.52 convert exchange 600USD b rate CAD want rate be same below is Canadian GBP. 600 1 US USD worth in Chinese Dollars = some Peso have how many Find 18 0 EUR. GBP (USD) AUD. into into into Great Australian Calculate British Pounds Dollars (AUD). CAD. how much your convert 500 rates AUD for the into USD. Japanese Yen (JPY). JPY 0 .053 how to Krone 1250 has how you 855 Yen will Yen Mexican nearest he exchange Give Pesos will Pesos Peso. 6 Quantity to receive. Mexican many many the 0 .066 Japanese Yuan friend correct into 0.0076 Calculate c USD 0.12 Yuan You Your (CAD) 870 exchange 1 Norwegian b 1.26 rate, Euro a 750 AUD. exchange shows Dollars Convert Currency Mexican Convert USD. Convert The 5 (USD) a (GBP) 4 1 to for your Chinese answer exchange for Yuan. to the Calculate nearest Japanese Yuan. Yen. receive. there are to the Euro. Give your answer may so conversion Example A coin found? be (as 2) in you given 666.65 CHF 666.70 CHF. or N U M B E R Problem 6 a The solving exchange rate from Turkish Lira (TRY) to Euros (EUR) is On 1 TRY = 0.25 EUR. What is the value of 1 Euro in Turkish January 1999, b Victor receives 500 Swiss Francs (CHF) for 400 this information to nd the value of 1 the concept EUR. of Use Euro in Swiss the Euro 7 Find Use to the the value of exchange 1 Turkish rate table Lira here in for Swiss this coins Francs. question. Give answers and notes recognized legal tender BRL CRC 1 However, members 1 USD 1 1 BRL 0.3976 2.580 1 0.001865 207.8 (EU) 0.004812 have into In Brazilian Brazil, Costa In Andrew the table trip Real spent Rica answers a he in 350 US. He converted Calculate BRL. (CRC) spent his the (BRL). Colón converted that Give he Rican Costa He Copy started Then did he 200 000 remaining Euro how he CRC. below correct and to 3 1 BGN 1 CLP adopted as their BRL Costa his he into US Dollars he Rica. returned (USD) received. How remaining USD. currency. to many BRL? the Calculate US. the amount nd the exchange rates for the three currencies. s.f. AOA AOA to for Then back 750 many went receive money Union received. (Angolan 1 all the 1 common Andrew not 536.1 the 1 CRC 8 from 2001. of European c BGN Kwanzy) CLP (Bulgarian 1 Lev) (Chilean 0.0170 Peso) 6.03 ATL Exploration 1 1 €100. You start value 2 You of Convert amount 4 with €100 spend original 3 as correct 4s.f. USD b and were January a was Francs. introduced c 1 Lira? Repeat in 75% of amount the you the have steps your a currency you left is converted have 25% for: £ (Japanese converter site or app to nd the (USD). Calculate above ¥ (Venezuelan Use Dollars left. money Dollar/AUD); Bs US left of €100, how back your (Great so much into initial British Yen/JPY); $ you have money Euros. only you 25% have Decide left of your in USD. whether the €100. Pounds/GBP); (Mexican $ (Australian Peso/MXN) and Bolivar/VEF). 6.1 Can I exchange this please? 181 Financial C ● When are Exploration Claudia 2000 1 lives Euros in into Calculate Before 1EUR = Germany. many Calculate 3 Determine 4 Calculate dierent currencies equivalent? is planning at Canadian a sells holiday of Dollars Germany, She a rate the 1 she Claudia Dollars to EUR Canada. = 1.39 She exchanges CAD. receives. becomes back to ill the and bank has at a to rate of CAD. how many how Euros much Claudia’s Selling in Dollars leaves holiday. 1.48 2 She Canadian even cancelher quantities 2 how she mathematics (Going money loss on she as a receives. the bank makes percentage holiday) of from her the original Buying (On two transactions. 2000 return EUR. from holiday) The If you have country to is a currency (HC) foreign selling The bank’s CAD is = (FC) a then fee buy change the If it that bank have you home another. The foreign want to currency buying foreign-exchange into and you and currency. currency they to home your currency change (HC) foreign providers commission then to the your bank is and rates from the view of are point the of bank. currency. charge is it buying selling (FC) for charged in the sell. 3 0.73 5000 = your want foreign exchange CAD Convert one that Example 1 the commission currency is1 you currency you exchanging A and from rate USD. CAD 0.73 to from The Canadian bank USD, Dollars charges taking into 1% (CAD) US Dollars (USD) commission. account USD to the bank’s commission. Write out the exchange rate. First multiply both sides by 5000 5000 × 1 CAD = 5000 × 0.73 USD to work out the conversion. 5000 CAD = 3650 USD Find 1% of the conversion to work 3650 USD × 0.01 = 36.5 USD out the cost of the commission. Subtract the cost of the commission from the conversion 3650 USD − 36.5 USD = 3613.50 USD to nd out how much you would receive. 18 2 6 Quantity N U M B E R Practice 1 1 US 2 Dollar a Convert b A (USD) 840 = USD commission of 0.90 into 1% Euros (EUR). EUR. is charged for the conversion. Find the cost of the More commission in than worth c Calculate the nal number of Euros received. 1 CHF = 1.02 USD. A commission of 1% is 3 The 3500 exchange Rand (RND) Convert 800 You want bank. charge of 3 Your S The A be the answer the For are rates this 1 going each of at the Seren GBP 2 In fountain the Pounds The (GBP) bank into charges South 2% every in day. African commission. is least by (GBP) = 1.30 Francs some of in into CHF. Swiss There Francs is also (CHF) a xed at your bank GBP Swiss GBP could and received Francs of buy with 430 133 CHF. GBP. Calculate how EUR per Euros amount received in exchange for B British B into charged 320 you exchanged. terms from 1% GBP transaction. she of in is 1 GBP = 1.27 EUR. transaction. spending GBP money he needs by two to for his holiday. convert. Give your Pound. 3 compare of the the next her the journey two stage (AUD) she many to started Dollars S nearest stage oered for RND. Pounds 1 Swiss minimum the is each number Exploration You British rate Pounds rate wants to British 21.33 are the RND. many Express commission Calculate into = exchanged British exchange Nathan Great for how friend Pounds. 5 from GBP change GBP b Let USD. exchange Calculate c into into solving a many 1 GBP to The rate is Problem 4 CHF coins charged. Rome Convert in thrown Trevi 2 $2500 EUR. trip the in oered below, banks. of into rates work Decide on out the banks: Bank 1 and Bank the conversion using best conversion and 2. the then use journey. Australia. Great British She converted Pounds 1600 (GBP). Australian Calculate how many received. UK she Euros spent she 520 GBP. received for Then her she went remaining to France. Find how GBP. Continued on next page 6.1 Can I exchange this please? 18 3 3 In France, Seren Sheconverted amount that spent her 190 EUR. remaining Seren Then money GBP GBP EUR EUR sells buys sells buys 0.485 0.515 0.62 0.66 1.271 1.299 1.94 2.06 1 EUR 1.465 1.565 Bank AUD GBP 2.0 1 EUR 1.553 that 1 a have currency commission) GBP buys/sells EUR buys/sells 0.668 0.793 2 dierent conversion buying sites and only selling oer a rates? single conversion rate. this? is the dierence in nancial currency might Practice 1% 1.323 discuss banks work How 0.787 0.52 and foreign ● buys/sells 1 What 0.753 (charges AUD Whyis ● 2 1 Many 1 AUD GBP ● the buys 1 do Australia. Calculate sells AUD Why to AUD. AUD 1 ● returned into received. Bank Reect she back you to between sites institutions go decide on that and provide those information aimed at people for people needing a holiday? which bank or foreign exchange center to use? 3 Dafydd is going on holiday. He wants to exchange 700 USD Buy for AUD. Use the table to calculate how many AUD he 1 USD receive. b Bernice 980 USD 2 The ve has AUD she table returned back will shows other into from USD. holiday. Use the to to exchange calculate how a bank’s exchange rate between 1 Danish (ALL) France Mexico Buy DKK 19.25 1.17 1.28 0.13 0.15 (CAD) 0.19 0.22 (MXN) 2.21 2.24 (HKD) (EUR) Canada DKK 18.75 Kong many Krone currencies. Albania 18 4 wants receive. Sell Hong She table 6 Quantity AUD Sell AUD will (DKK) and 1.395 1.379 N U M B E R a Your into they b friends receive Your they A they are table below bank charges exchange in to two exchange travel so CAD Mexico, Pesos decimal 1500 they they into CAD and into lost returning DKK their on the shows a part 1% of a currency commission after conversion the GBP USD CAD USD 0.65 1 q 1 CAD 0.53 0.81 1 calculations Calculate the this the taking He UK Christine Shillings Denmark number of their back holiday. into CAD. lives 1 buys Bank 2 has 1 an from to In the give USA exchange spends whether at a bank. your answers correct to 2 d.p. 890 GBP. Canada he has to 1500 he He plans enough the UK USD. then to CAD and How then many exchanges stay for in a a his hotel hotel home GBP he via receive? remaining for room again will three nights. charged at night. in (TZS) question chart q trip CAD. per Bank a wants Stefan into CAD to the of: ii Determine 45 in value p money Pesos conversion. 1 In DKK transaction. 1.90 is before money p Stefan 600 Mexican Calculate 1 all of places. exchange have on Krone. GBP Canada. c they number 1 i b the solving The a to many The For MXN remaining correct family leaving, Calculate DKK. 300 their how Problem 4 spend Before (MXN). 600 unable Calculate Mexico. receive, Canadian They 3 for friends to Pesos exchange DKK c go Mexican Tanzania. into TZS US for She Dollars 0.0005 exchange rate wants USD, of to exchange 350 000 Tanzanian (USD). 1 and TZS = sells 1 TZS 0.00051 for USD, 0.0004 and USD. charges a 1% commission. At which bank would you advise Christine to exchange her money? 6.1 Can I exchange this please? 18 5 Currency D ● How do as a systems quantity inuence communities? ATL Exploration 1 Compare the 4 DETECT currencies for each group of countries Group in the tables. grouped in Decide this why the countries have 1 Dene 2 Examine the 3 Track task A been France way. information Germany 2 Research the bitcoin and answer these down questions. Spain sources a What is the bitcoin and how does it and nd Greece work? information in Italy those b Who created the bitcoin? Why was the sources bitcoin 4 Extract developed? meaningful Group c Is the bitcoin secure? Is it B legal? information Denmark 5 3 Exchange rates are constantly Create United Research ve currencies and analyze change in the last year. Group b Determine which about this have changed the most. C Think Switzerland why might be. Sweden Serbia Reect Single and discuss 3 currency: ● Why have ● Why do ● What some some are the European EU countries countries advantages opt and out decided of the not to join the EU? Euro? disadvantages of a single European currency? New currencies: ● Does the ● Does every extent does Exchange ● Of 17 What the of bitcoin person most them do letters use you are capital future? inuence right equal traded a to create access world exchange currencies, strikethrough think used the in the rather their or symbol. struck-through than just letters? 18 6 the have to rates: double-strikethrough Why a have everyone factors 20 have 6 Quantity plain inform others the 6 percentage product Kingdom to a a changing. rate? their these own currency? opportunities? To what Task reection N U M B E R Summary A rate value The of of exchange, one commission providers Mixed 1 1 EUR or currency charge is a for exchange in terms fee that rate, of gives another the currency. foreign-exchange exchanging one currency into another. currency The buying view of the = 1.10 Convert 6 USD. The 950 EUR into 1 buy and selling who rates is is charged in the sell. are buying from or the point selling of currencies. exchange Convert 2750 USD Mexican Peso into (MXN) Baht rate from (THB) is US 1 Dollars USD = (USD) 33.45 THB. USD. = the answers to the following correct EUR. to 2 and bank, Thai Give b commission they practice to a The that 0.055 US 4 s.f. Dollars a Find the value b Calculate of 115 US Dollars in THB. (USD). a Convert b A 4400 MXN into c commission of 1% is c the cost Calculate of the the nal Alexis receives commission number of in of USD. USD d received. 1 for THB 1 CHF = charged. 0.72 GBP. Convert A commission 1600 CHF into of 2% 7 4 RUB A bank a GBP Sell 107.30 Jasmine She wants Russian is to going Rubles for holiday. exchange buys how 1400 GBP for a Find b Frida RUB she will Kali She has wants Calculate 5 The table returned to change how many below conversion from chart. holiday. 1420 RUB GBP show part Find the she of GBP AUD 670 New THB. value 1 of Zealand Dollars Calculate the Australian (EUR) Frida how has US the Dollar Dollar and a back will to GBP. of c to 1 sells to Euros cancel back AUD value in New (AUD) 1 AUD exchange = Frida her later 0.73 8 p and q Ed EUR GBP AUD had Swiss 1 p 1.53 1.27 1 1.92 q 0.52 1 2% a b lost to on for 800 AUD trip and when EUR, will receive. changes the rates sells 1 are 1 how many AUD = Australian receives. how the change Francs was Find she Determine has receive. currency value wants many EUR’. Dollars rate EUR 600 receive. 0.69 b USD. NZD. the hermoney (RUB). many in EUR. ‘buys Calculate THB RUB 105.80 on 1 Dollars. 0.72Euros 0.70EUR. 1 of is GBP. for Buy 14 in Calculate Zealand 3 value charged. (NZD) Find the USD. many = Dollars she transaction. British (CHF) GBP Australian at 1.4 a Pounds bank. CHF. (GBP) The The into exchange bank charged commission. Determine how bought with Ed 100 has Find how many 200 CHF many Swiss Francs Ed GBP. of his British initial amount Pounds 6.1 Can I exchange this please? he left. could 18 7 buy. 9 Santiago 67 000 lives in Mexican Mexico. Pesos He wants (MXN) into to change Euros a Calculate Pavla leaves Zealand. A bank buys 1 MXN for 0.051 EUR and MXN for 0.0531 exchange 1MXN = of THB Pavla buys. has 20 and 000 travels THB to and New uses buy New Zealand Dollars (NZD). these The EUR. center has an exchange 0.054 EUR and rate is 24 450 THB = 1000 NZD. rate b of Thailand She exchange An number sells to 1 the (EUR). charges Calculate the total number of New Zealand a Dollars Pavla receives. 2%commission. c Find the EUR dierence he would exchange between receive the from number the bank Find an New Zealand Give your Pavla She travels from changes Baht. The Review The in He is rate and He into is Republic Koruna 1 CZK to bank a and b of will rate is of Determine Let 1330 s be Jim’s and be = company starting a exchanging Dollars 1 GBP = 10 GBP for how to the 2.07 many are in British 2 the company Andy, to in (SGD). SGD, each SGD b of GBP . of the 15 000 account. to and Jim SGD there is s in in used could used Jelena 10 The buy second He rate year, from has can two use Jim ways the of = SGD, for each Singaporean 2% = for 0.49 and which to How you have and human-made 18 8 3000 his USD to USD 3000 to the USD buy buy to Swiss USD Francs. Brazil buy exchange conversion Reals. and at Swedish rates per ve-year 2010 CHF 1 Krone. USD at intervals. 2015 0.97 CHF 0.85 CHF 2.50 BRL 1.52 BRL 3.29 BRL 7.25 SEK 6.40 SEK 9.30 SEK UK bank (the Ignoring any there is a bank bank buying and selling costs: Calculate (the or he exchange and there is a can rate bank chosen the better discuss explored the Calculate and of illustrate inquiry? the person received 2005. amount in USD each person receive if they chose to sell in 2010. charge c communities. 6 Quantity the Calculate if the amount they chose to USD in Give specic examples. relationships between each to option. statement each in use 3 measurements systems amount currency is transaction). is the charge Statement of Inquiry: Quantities 3000 to his back and had converting British transaction), bank GBP, each Reect each b receive Decide 3000 shows of would SGD of = is 2.06 GBP Jelena 2005 of needs Singapore and his table time in terms b 1 NZD 2005. his used their the 1 a a GBP of form Pounds received Express SGD He GBP . exchange 1 the d.p. The transaction. SGD Neil invest the number for end transfer bank in 2 1.34THB. 1.32 At to Thai GBP. the exchange c answer correct sustainability Singaporean charge with between Koruna. Thailand. (CZK) Neil exchange rate Czech the Andy (GBP) and context expanding Singapore. Czech Czech exchange headquarters UK. the 29 000 Globalization 1 exchange Dollars center. xCZK, 10 approximate of 2015. person convert it would in City skylines 6. 2 Global context: Objectives ● Constructing relative Globalization Inquiry and interpreting frequency histograms frequency with equal ● and F class and sustainability questions What are chart and How do the a dierences between a bar histogram? widths ● ● and interpreting histograms with unequal Describing distributions frequency class density C you distribution accurately from a analyze a data histogram? widths ● How can ● How do real data ever be misleading? D individuals stand out in a crowd? ATL Critical Revise thinking understanding based on new information and evidence Statement of Inquiry: 4.1 How to quantities establish trends in a are represented underlying can help relationships and population. 4.2 6.2 18 9 SPIHSNOITA LER ● Constructing Y ou ● should represent discrete already continuous data frequency in a know how and 1 to: The grouped heights (rounded to measures grouped of and central dispersion frequency 2 from 5.8, 2.2, 4.9, 3.0, 4.7, 5.3, 2.6, 4.5, 3.7, 2.3, 5.4, 5.7, 3.5, 2.1, and 3 your modal contains Before char ts now, you quantitative are the may discrete representing frequency for this frequency class the 4.1 and the table data. table, class median. estimates for the mean and range. as qualitative or quantitative data: shoe c What 2.8, widths grouped that b ● 2.5, grouped the a Bar 3.6, class nd Classify data 4.2, a equal From a table qualitative quantitative F are: 2.6, the recognize seedlings 5.2, Calculate ● d.p.) 24 3.1, with tendency of 2.4, Construct nd 1 cm table 4.0, ● in and data. quantitative drawn is shoe a between bar However, data shoe color price frequency dierences have size charts strictly a bar for histograms chart both and a histogram? qualitative speaking, a chart and with bars histogram. A bar char t y A bar chart represents qualitative data. 30 All ● There the bars are have spaces ● The ● Frequency height of the equal between bar 25 width. the ycneuqerF ● bars. represents the 20 15 10 frequency. 5 is on the vertical axis. 0 x Cat A histogram represents quantitative discrete data and all Dog A Rat Parrot Snake histogram y continuous data. 8 7 ● ● bars There The may are area no of or may spaces the bar not be of between equal the represents the width. 6 ycneuqerF ● The bars. 5 4 3 frequency. 2 1 ● Frequency, relative frequency or frequency density are 0 on the vertical axis. x 1.10 1.20 1.30 1.40 Height 19 0 6 Quantity 1.50 (m) 1.60 1.70 1.80 S TAT I S T I C S A N D P R O B A B I L I T Y ATL Reect and discuss The 1 word originates Decide which of these graphs are bar charts, which are histograms are neither. Justify your words: histos answers. meaning upright’ Favourite from and Greek which histogram colors Pupil to teacher ‘stands and ratio y gram y meaning ‘a 16 7 drawing’. 14 6 ycneuqerF 12 5 egatnecreP 4 3 2 10 8 6 1 4 0 x Blue Red Green Orange 2 Color 0 x <18 18 19 20 21 22 23 24 25 26 27 Over 27 Pupil/Teacher ratio Lengths Mid-term examination of leaves scores y y 25 12 25 10 ycneuqerF ycneuqerF 8 6 4 2 20 15 10 As the scores not 0 24 26 28 30 32 34 36 38 40 42 44 x 0 x 40 60 Score 80 Length 100 120 140 the start zigzag values histograms for continuous one table Weight, some not on the axis. 1 shows week. symbol data scores Example zero, that are included Frequency at (mm) indicates The do 5 Draw x the a (grams) 19.5 < x ≤ 20 weights histogram in grams to Freq 3 of 50 represent baby the chicks hatched at a farm in data. Weight, x (grams) 22.5 < x ≤ 23 Freq 4 20 < x ≤ 20.5 5 23 < x ≤ 23.5 6 20.5 < x ≤ 21 1 23.5 < x ≤ 24 5 21 < x ≤ 21.5 6 24 < x ≤ 24.5 5 21.5 < x ≤ 22 2 24.5 < x ≤ 25 6 22 < x ≤ 22.5 6 25 < x ≤ 25.5 1 Continued on next page 6.2 City skylines 19 1 y 7 Use your frequency table to draw 6 the histogram on graph paper. 5 ycneuqerF 4 3 Plot the class boundaries on 2 thex-axis and the frequency on 1 the 0 19 20 21 22 23 Weight 24 25 y-axis. Draw the bars with x 26 nogapsbetween them. (g) 7 6 5 ycneuqerF 4 3 Use a GDC to check 2 your histogram. 1 0 19.5 20.5 21.5 22.5 Weight In to Example one 1, the decimal 23.5 weights place, 24.5 25.5 (g) so a are continuous histogram is data, the even correct though they are rounded representation. The are class intervals sometimes ATL Reect Ages are nearest If a and rounded meter, woman continuous The discuss table is its dierently height 40 years gives the ● What ● How would are 1 The most her age centimeter, Height of h < If a r tree is 10 meters tall to the 10.5. satises 40 ≤ a < 41, where in an a is a orchestra. 26–33 34–41 42–50 5 8 10 7 draw class you bars on boundaries write the class of the are chicks recorded (cm) from a histogram for each interval, in Example this to show these ages? class? using ≤ and ≤ x < 2.5 1 ≤ x < 3.5 3 3.5 ≤ x < 4.5 7 4.5 ≤ x < 5.5 14 5.5 ≤ x < 6.5 18 6.5 ≤ x < 7.5 5 7.5 ≤ x < 8.5 2 frequency grouped 1, measured frequency Frequency 2.5 19 2 a musicians 1.5 a data. ≤ <, for the class 1 heights Draw 9.5 18–25 you the would Practice to satises old, ages Frequency How h called quantity. Age ● 2 histogram 6 Quantity to represent the data. to the table: nearest 18–25? bins. S TAT I S T I C S 2 The ages of 100 shoppers Age 14 ≤ Number of users Draw a 3 The the < 24 24 ≤ x < for a 34 survey 34 ≤ 30 histogram to represent x are < given 44 in 44 ≤ 15 the the x < P R O B A B I L I T Y table. 54 54 8 ≤ x < 64 6 data. solving incomplete masses x chosen 41 frequency Problem randomly A N D (to table the and frequency histogram nearest kilogram) of some give some female information polar about bears. y 16 14 12 ycneuqerF 10 8 6 4 Class Class inter val boundaries Frequency 80–119 79.5–119.5 15 120–159 2 160–199 70 90 110 130 150 Mass a Use b the You histogram Complete Frequency can 200–239 x 0 the to 190 210 230 8 250 (kg) complete the table. histogram. histograms represent 170 for discrete ungrouped data discrete Eggs data hatched in incubators y with a ver tical line graph. 30 This type discrete of graph data. A is not single suitable ver tical for line grouped to 30 represent 22 but categor y 1–3 separate eggs lines at could 0, 1, 2 be and misleading, 3 could be confusing. ycneuqerF the 20 18 20 15 12 10 10 8 4 2 1 0 0 0 1 0 2 3 4 5 Number A histogram for grouped discrete data For to represent discrete from upper lower data, the 1–3, point boundar y boundar y of of group. 4–6, 7–9, halfway one the etc., plot between class eggs 8 9 10 11 12 hatched hatched in incubators y inter val the the and the next. 100 ycneuqerF bars each of 7 uses Eggs bars 6 80 60 40 20 For 4–6, Star t the plot the rst same the bar width. bar at between 0.5, to 3.5 make and all 6.5. the bars 0 x 1 2 3 4 5 Number 6 of 7 eggs 8 9 10 11 12 13 hatched 6.2 City skylines 19 3 13 x A histogram 1, 2, 1.5 3, to 4 … 2.5, class ungrouped and plot bars so from discrete 0.5 to y data 60 1.5, 50 on. 40 ycneuqerF You for uses the intervals 30 20 10 of cumulative frequency curves in 0 x 1 a similar way. Practice 1 The Number table shows of the numbers people Frequency a Classify b Represent There the were unhatched 3 data the 25 as data trays eggs. 18 17 13 9 21 2 5 12 1 14 11 13 15 18 21 14 15 9 12 14 15 16 24 in grouped b Construct a frequency lengths cm. of of 30 The Swiss table the Determine b Draw taxi the 8 11 6 4 2 2 or continuous, frequency in an of incubator. cheese shows for plant the that table histogram or ungrouped. histogram. eggs frequency grouped Each tray hatched for the this leaves started from each with tray 24 were: data. data. were measured to the results. of ≤ x < 15 15 ≤ whether records a x < 20 20 ≤ x < 25 25 ≤ x < 30 cm) frequency driver course cars. 6 3 a A 33 5 Frequency 4 in leaf nearest a travelling 4 10 (to people 3 eggs a Length orders 2 numbers Construct nearest of 4 1 a a The of discrete of The 12 5 3 2 Number 2 2 long this is 8 discrete histogram the to distances weekend or 12 continuous represent of his the 7 data. data. journeys, to the nearest km, shift. over For 9 Distance (km) 1 5 6 grouped continuous 10 11 15 16 20 21 25 12, etc. 13 are the intervals. Frequency 10 6 8 5 Write down b Determine the the modal class class. boundaries for each Draw 19 4 a frequency histogram 6 Quantity for this boundaries are 8.5 8.5 < x class. so c data. class The 2 class a data, 16 on. 12.5 ≤ or 12.5, and S TAT I S T I C S Problem 5 This A N D P R O B A B I L I T Y solving histogram has no title or axis y labels. ATL a Determine whether it represents discrete 35 or continuous data. 30 b Suggest what the c Do think data could be. 25 you that the data represented 20 here contains any outliers? If not, why not? 15 10 5 0 6 The histogram that Macey day in shows spent the doing number of homework hours 1 2 3 4 5 6 4 5 6 7 x y each 9 June. 8 a Use the information histogram to in construct the a frequency 7 grouped 6 frequency Use an your frequency estimate for the table mean to ycneuqerF b table. calculate time that 5 4 3 Macey spent doing homework. 2 1 0 1 2 3 T ime Distributions C ● How do you in x (hours) histograms accurately analyze a data distribution from a histogram? Examining data set To it a histogram can help you visualize certain characteristics of the represents. comment on the distribution of Center measure of central Spread measure of dispersion Outliers extreme Shape unimodal, data data, describe: tendency values bimodal that or don’t t the pattern multimodal 6.2 City skylines 19 5 Example This 2 frequency caught in the histogram Kispiox shows River, the British lengths in centimeters Colombia, of 57 sh Canada. y 11 10 9 8 7 ycneuqerF 6 5 4 3 2 1 0 10 20 30 40 50 60 70 Length a 80 90 100 110 120 130 x (cm) Find: i the modal ii the class iii an class interval estimate b Describe a i The ii 57 the the contains the median range. distribution. modal data for that class is 60 ≤ x < 70. items Count The median The class = = 29th item of each iii b Estimate The is median also the caught There Most 90 ≤ are x < for ≤ x the lies in modal are sh 60 contains range the have = 120 class The spread outliers. caught 100 70 class. widely no < 60 ≤ 20 x < 20 60 ≤ = 100 70 of cm x bar, 6 Quantity of data items in until you reach the 29th. < and the to cm this sh 120 is 70 cm. bimodal. cm or To describe measure and a State of a distribution, central measure if there describe 19 6 number median. distribution length cm. – lengths from The the the data. the is of use tendency dispersion an outlier, shape. a (center) (spread). and S TAT I S T I C S These same three 50 histograms eggs ungrouped measured data, all show one appears to the week be a weights, before multimodal Ungrouped to the hatching. nearest The gram, rst of A N D P R O B A B I L I T Y the histogram, for distribution. data y ycneuqerF 6 4 2 x 0 35 40 45 50 55 Weight 60 65 70 75 (g) 4 class inter vals y This appears to be a unimodal distribution 24 43 ≤ w < 53) that is not ycneuqerF (at symmetrical. 18 12 6 0 x 35 40 45 50 55 60 Weight 10 This that appears is fairly to be a bimodal class 65 70 75 (g) inter vals y distribution 15 symmetrical. 12 ycneuqerF 9 6 3 0 x 35 40 50 45 Weight Reect ● How ● What and can are discuss changing the the eects of 60 55 65 70 75 (g) 3 class intervals having too change few the classes? shape What of a about distribution? too many classes? ● How of many the data Practice 1 is set intervals when should deciding on you the use? Do number you of need to consider the size classes? 3 Determine i class whether each histogram: symmetrical ii is a unimodal, bimodal or multimodal iii b contains outliers c y y 16 y 140 12 fo 8 rebmuN ycneuqerF 10 6 4 120 100 ycneuqerF slaudividni 14 80 60 40 20 2 032 022 012 percentage 002 fat x x 50 Body Body 091 45 081 40 071 35 061 30 051 25 041 x 20 031 0 0 mass (g) Spanish 6.2 City skylines test score 19 7 2 The 26 histogram black lengths y of 10 b Find down the the class modal interval class. that 8 contains ycneuqerF Write median. c Calculate d By rst an the estimate constructing frequency for the rats. a the shows table, mean for a the range. 6 4 grouped calculate an 2 estimate length. 0 x 28 e Describe the Problem 3 The to 44 40 Length 48 52 (cm) solving histogram money, 36 32 distribution. the shows nearest the amounts $10, y of 18 some 16 families spend on food each week. 14 Write down b Calculate amount the an total number estimate spent on for the of families. 12 ycneuqerF a mean food. 10 8 6 c Comment on the distribution of the data. 4 2 0 x 145 155 Amount 4 5 Imogen a Explain b Sketch Here are nature why a bar the she chart in in her should weights reserve the to class use predict (to the Snowy a to bar what nearest tell her chart the to their show whole kg) of 50 35 36 24 29 29 29 34 38 35 35 35 36 60 35 50 34 48 41 41 51 42 35 36 32 61 30 40 41 19 33 34 17 35 35 38 35 42 20 29 50 33 37 28 49 58 45 40 b Describe order data frequency the to make points, you histogram fair the comparisons use a total for this relative between frequency frequency axis. 19 8 175 ($) month. results. would emus look in an like. Australian data. histograms can of food distribution. frequency proportion vertical a the 165 on Mountains. 24 Construct birthday distribution 19 a the everyone 33 Relative In asked spent 6 Quantity in data sets histogram. each class with dierent Relative interval. It numbers frequency is plotted of shows on the S TAT I S T I C S Objective: v. justify real-life This in Applying whether a mathematics solution makes in real-life sense in the P R O B A B I L I T Y contexts context of the authentic situation exploration an the D. A N D authentic comparison encourages real-life of data students context. makes The sense to see mathematics students in this should specic be as a able tool to for solving justify problems whether or not case. ATL Exploration The frequency Kalamazoo show the Sable 10 < x ≤ 20 2 20 < x ≤ 30 52 30 < x ≤ 40 93 40 < x ≤ 50 30 (cm) < x ≤ 60 25 60 < x ≤ 70 33 70 < x ≤ 80 30 80 < x ≤ 90 30 90 < x ≤ 100 40 100 < x ≤ 110 25 110 < x ≤ 120 30 120 < x ≤ 130 5 Draw both, sh x ≤ 140 Copy b Find the Au Sable and the each the River Length, x 10 < x ≤ 20 0 20 < x ≤ 30 8 30 < x ≤ 40 15 40 < x ≤ 50 30 50 < x ≤ 60 10 60 < x ≤ 70 11 70 < x ≤ 80 10 80 < x ≤ 90 7 90 < x ≤ 100 7 (cm) Frequency 100 < x ≤ 110 8 110 < x ≤ 120 1 120 < x ≤ 130 2 130 < x ≤ 140 4 Total frequency with a in 7 frequency a caught Frequency 50 Total of Kalamazoo x < lengths River Length, 130 2 tables rivers. Au 1 1 histogram y-axis table, total from 0 adding a frequency for to each set. Use the same scale for 100. third of data frequency each column data for ‘Relative frequency’. set. c Round d Draw the a values relative boundaries 3 Look a of b at sh of in tendency? the set places histogram and is class with frequency two relative n What the should rivers? histograms frequency data relative of the central a x-axis histograms lengths in decimal and for add each to your data frequency tables. set. on the Plot the class y-axis. histograms. pair pair belonging 2 frequency the Which Relative For your Which on to you the proportion use Explain should about you to the distribution fully. use to measures (or compare nd of the measures of dispersion? percentage) of the data set interval. members, a class interval with frequency f has . 6.2 City skylines 19 9 Practice 4 Tip 1 The tables show the length of time some men and women spent on their ATL mobile phones Time one spent minutes day. in When Frequency Time (men) spent minutes in Frequency two use (women) descriptive words 0 ≤ x < 15 5 0 ≤ x < 15 comparing distributions, such wider, 15 ≤ x < 30 8 15 ≤ x < 30 5 30 ≤ x < 45 10 30 ≤ x < 45 7 45 ≤ x < 60 5 45 ≤ x < 60 14 60 ≤ x < 75 2 60 ≤ x < 75 20 more Explain these 2 why data b Calculate c Draw d Describe e Compare the The the tables Mass, length the a relative m frequencies for histograms of time masses Siberian (kg) frequency histogram to compare each for class the interval. two sets of data. of spent on the some male phone and husky by female Female Frequency the Mass, m men and Siberian Siberian (kg) women. huskies. husky Frequency 17 ≤ m < 19 3 17 ≤ m < 19 5 19 ≤ m < 21 6 19 ≤ m < 21 8 21 ≤ m < 23 6 21 ≤ m < 23 4 23 ≤ m < 25 11 23 ≤ m < 25 2 25 ≤ m < 27 9 25 ≤ m < 27 0 b Draw c Comment the relative relative Siberian Problem a use distribution. show Calculate at to frequency each a The need relative relative Male 3 you distributions. on frequency frequency the of each histograms distribution of the for class each masses interval data of the as a percentage. set. male and female huskies. solving histogram shows community the relative fundraising frequency event. There of were items 32 sold items at in dierent total. y 0.25 ycneuqerf 0.1875 0.125 evitaleR 0.0625 x 0 1 6 11 16 Selling Calculate 20 0 how many items 6 Quantity sold for less price 21 26 31 (dollars) than 16 dollars. 36 prices narrower, varied, varied. a as: 4 less S TAT I S T I C S Histograms D This ● How can ● How do stem-and-leaf gram, of stem 0 sh real data ever individuals diagram caught with in a unequal be class A N D P R O B A B I L I T Y widths misleading? stand out in a crowd? represents the weights, measured to the nearest river. leaf 8 8 9 2 1 2 2 2 3 4 8 3 2 3 5 5 5 6 7 7 4 1 2 2 3 3 3 3 3 3 3 3 3 3 3 3 3 4 4 4 5 6 6 6 6 7 7 7 7 8 8 8 9 9 9 9 9 1 1 1 2 2 3 4 4 4 5 5 5 6 6 6 6 6 7 7 7 7 7 7 8 8 8 8 8 8 8 8 9 9 9 9 9 9 9 0 0 0 0 0 0 1 1 1 2 2 2 3 3 3 4 4 4 4 4 4 5 5 6 6 7 7 8 8 8 8 9 9 9 0 0 1 2 4 5 5 5 7 8 1 5 6 7 8 9 Key : Both This into This 2 these | 5 histograms histogram small means class grouping 25 g show represents intervals has the the of resulted weights, data equal in to the nearest of the same 136 sh. grouped 50 width. three gram, 45 class 40 intervals containing no data. 35 ycneuqerF 30 25 20 15 10 5 0 10 This into histogram fewer, represents wider classes the of data equal 20 30 40 50 60 Weight (g) 40 60 70 80 90 100 70 80 90 100 grouped width. 80 70 60 ycneuqerF 50 40 30 20 10 0 10 20 30 50 Weight (g) 6.2 City skylines 2 01 Reect and Why using does comment Both are of the is small shape histograms when concentrated histogram where Using a the appropriate data the on discuss the with data unequal river could Weight number of are data a accurate is very classes class widths, like wide classes make representations spread You where concentrated look of it dicult to distribution? together. wide is 4 can the out, and combine data is of the narrow these spread data. classes ideas out, Wide to and help create classes when a narrow the better classes together. the grouped frequency table for the sh caught in this: (g) Frequency 0 < w ≤ 30 10 30 < w ≤ 40 8 40 < w ≤ 45 20 45 < w ≤ 50 16 50 < w ≤ 55 12 55 < w ≤ 57 11 57 < w ≤ 59 15 59 < w ≤ 61 9 61 < w ≤ 65 14 65 < w ≤ 70 11 70 < w ≤ 100 10 Class width 30 g Class width 10 g Class A frequency histogram to Class represent this frequency table looks like this: 25 ycneuqerF 20 15 10 5 0 10 20 30 40 50 Weight Reect ● Do ● Does and you it think obey proportional Because classes the have 20 2 discuss this the to height ended of up 60 70 80 90 100 (g) 5 histogram principle the represents that in a the data histogram, well? the area of each bar is frequency? each bar looking 6 Quantity is width its frequency, much too large. the bars representing wider 5 width g 2 g S TAT I S T I C S Frequency density When is data proportional In a For for the sh 0 < density ≤ intervals the data data, 30 histogram, class density weight w class of so unequal that the widths, area of bar to frequency each bar is has the area of each represent is plotted the rst frequency this bar is equal to the interval. on the vertical axis. class height 10. Area The a frequency. that frequency interval in represents the frequency frequency The to P R O B A B I L I T Y histograms grouped densityhistogram A N D class = frequency = 10 (frequency interval density) has width What is 30 the and area height of 10. this rectangle? class For any rectangle, Rearranging area = height frequency = frequency this Example The in to the frequency Weight, gives nearest x (g) Freq ≤ x < 19 14 19 ≤ x < 21 10 21 ≤ x < 22.5 22.5 ≤ x < 25 10 25 ≤ x < 28 7 a Weight, the 30 so: density × denition class of width. frequency density: (g) gram, of 50 Blue Heron chicks are given 9 frequency x whole table. 14 Construct width, = 3 weights, this formula × width density Freq histogram Class width for this data. Add Frequency 14 ≤ x < 19 14 5 2.8 19 ≤ x < 21 10 2 5 21 ≤ x < 22.5 9 1.5 6 22.5 ≤ x < 25 10 2.5 4 25 ≤ x < 28 7 3 2.3 columns frequency density for class density to width the = Round degree Continued on next decimals of to and table. = a 2.8 suitable accuracy. page 6.2 City skylines 20 3 Weights of Blue Heron chicks y 6 Draw with the histogram weight on the 5 horizontal axis frequency density ytisned the vertical ycneuqerF The rst from 2 14 height the bars bar to of 0 x 14 15 16 17 18 19 20 21 Weight Reect the What ● How modal would you class? work between weighed mode of of two a data data, each chicks chicks, all chick would with continuous – in case, The other that is modal Practice The is as data, class is most you class g? 28 the to the weights with with the the are weight. would interested are they weight nearest there really number estimate occurring chick same so the an Why commonly are the most greatest greatest data g, You be number estimates? point. if very would With you had likely the that probably have mode. where closely the even it’s no is chicks only data, 0.1 in of for the clustered frequency frequency data is most together. density: 21 ≤ x < In 22.5. density. 5 x in centimeters, (cm) ≤ x < 55 13 55 ≤ x < 60 20 60 ≤ x < 65 26 65 ≤ x < 72 19 a Copy and b Construct complete a of some Frequency 45 20 4 24 correct interval the 27 for about Heron weights, where class 26 this? estimate and exactly what words, g is What Blue recorded have an g? 22 the 25 (g) Why 20 the dierent the lengths, Length, set such than 24 3: out who dense 1 the 23 6 Example less weight this is in whoweighed continuous With discuss histogram ● 50 and 22 the frequency Class vipers width are recorded 10 histogram for in Frequency 1.3 table. density 6 Quantity horned this data. the table. density goes 19 and 2.8. with between no axis. 3 1 The on 4 a In and no them. has Draw gaps S TAT I S T I C S Problem 2 The ages A N D solving of people visiting the Eiel Tower are recorded in the table. In Ages, x P R O B A B I L I T Y (years) Frequency 2015 were visitors 0 ≤ x < 15 15 15 ≤ x < 25 28 25 ≤ x < 40 30 Tower. deck is above the 40 ≤ x < 60 there 6.91 to ≤ x < The Construct b From and the 80 i Explain ii State 3 State The your at The ground, highest you for medical gives 5 < L ≤ 7 15 7 < L ≤ 9 24 13 19 13 < L ≤ 16 9 16 < L ≤ 20 6 b Calculate The 100 table km Time, a frequency an 10 charity t estimate and shows 15 the b State c Calculate the and 2 a data. were 80 ten and visitors 100 years between 60 old. made. reasonable assumption. 80 patients about the in total lengths during of morning these for the histogram number of for the information. patients who saw their doctor for minutes. taken by members of a cycling club to nish a 110 < t ≤ 130 130 6 frequency modal an < t ≤ 145 145 30 density < t ≤ 160 160 45 histogram for the < t ≤ 55 185 185 < t ≤ 195 28 195 < t ≤ 16 information. class. estimate for the number of cyclists who took between 1 1 2 a see density times Frequency Construct there between has this ride. (min) a is for Frequency 7 Construct Union. minutes. 5 a the data. center ≤ ≤ this information L L that Voleta this < < visitors think class (min) between 4 in ten 0 9 in answer. table appointments L a and histogram estimates assumption modal doctors Length, old, the density Voleta whether the surgery. frequency years upper meters 20 graph, Justify c a Eiel 42 100 a the 276 European 60 million 3 hours to complete the ride. 2 6.2 City skylines 20 5 250 5 The histogram sports represents the distances students threw the javelin on school day. y In javelin the 11 distance of throw rounded the 10 is 9 down to the nearest ytisned 8 centimeter. 7 ycneuqerF 6 5 4 3 2 1 0 x 5 10 15 20 25 30 35 Distance 6 a Construct b Find c Calculate d Find This the the a frequency number an between Find 110 the interval for and number of 125 the that represents cm for the 45 50 55 60 65 distribution. throws. estimate class histogram of table 40 (meters) mean distance. contains children’s the median. heights. Fifteen children measured cm. children in the sample. y ytisned 5 4 ycneuqerF 3 2 1 0 110 120 130 140 Height 7 In of a histogram, 50. the A second height of a bar bar this of is 4 width cm 2 wide cm and and 150 160 170 x (cm) height represents 5 a cm represents frequency of a frequency 50. Calculate bar. Summary A ● ● ● bar chart All the There The represents bars are have spaces height of qualitative equal bar ● The ● There ● The ● Frequency, bars are the A Frequency histogram is on the represents the all represents continuous area vertical spaces not be of between equal the width. bars. of the are relative on the quantitative discrete represents the frequency. frequency vertical or frequency axis. data modal class is data. 6 Quantity bar axis. frequency 20 6 may frequency. The and no or bars. density ● may width. between the data. density. the class with the greatest S TAT I S T I C S To comment on the distribution of data, describe: For a with Center measure of central Spread measure of dispersion a data with frequency baris extreme set f n has members, relative a P R O B A B I L I T Y class interval frequency . tendency In Outliers data frequency A N D values that don’t t equal to density the histogram, frequency for the that area class of each interval. the The frequency density is plotted on the vertical axis. pattern Shape unimodal, Relative frequency is bimodal the or multimodal. proportion (or percentage) The of the data set belonging in the class modal frequency Mixed 1 The class is the class with the greatest interval. density. practice table shows the heights of 24 4 students. Fifty students eating Height, x (cm) Frequency The out results frequency 140 ≤ x < 150 6 150 ≤ x < 160 7 in recorded one are how month shown (to in much the the they nearest partially spent on dollar). complete table: Amount spent Class boundaries Frequency (dollars) 160 ≤ x < 170 6 170 ≤ x < 180 4 180 a ≤ < Explain used b 2 x to 190 why restaurant from one 8pm week. to the frequency set 9pm the on table histogram of frequency The 21–30 15 31–40 0 41–50 4 51–60 3 61–70 1 histogram. of consecutive the pizzas nights served during a results. Draw to of frequency weights nearest 13 be 5 6 8 9 10 3 8 12 4 5 histogram for this of 50 hoglets are recorded to the clearly this b State the modal c State the class d Describe label a frequency histogram information. class. the that contains the median. distribution. The in a table shows the age distribution of teachers school. gram. Age, 93 88 105 90 92 89 90 88 108 86 103 96 94 100 104 98 100 120 115 94 84 130 110 125 115 112 105 129 118 105 95 124 112 96 114 128 132 95 129 122 120 85 93 108 105 88 95 105 123 97 a and represent data. 5 3 14 data. number shows can 0.50–10.50 10.50–20.50 ser ved Frequency Draw a this records The Number pizzas a represent Construct A 1 1–10 11–20 Construct a grouped frequency table x (years) Number of 20 < x ≤ 30 6 30 < x ≤ 40 4 40 < x ≤ 50 3 50 < x ≤ 60 2 60 < x ≤ 70 2 teachers for a Calculate an b Construct c Describe estimate for the mean age. thisdata. b Construct a histogram to represent this a histogram to represent this data. data. the distribution. 6.2 City skylines 207 6 The and heights Peru of are 14-year-old given in the students from frequency Sri tables Lanka 8 below. In New old The Heights of students (measured Heights to the in Sri Lanka nearest cm) 130–139 11 140–149 14 150–159 8 160–169 6 (measured to the in Peru nearest x Explain cm) a 22 130–139 41 140–149 32 150–159 6 160–169 6 it is necessary frequency gives were asked their rst the how child. results. Frequency < x ≤ 20 6 20 < x ≤ 22 14 22 < x ≤ 25 19 25 < x ≤ 30 21 30 < x ≤ 40 30 Determine the to Construct c Calculate histogram to type of histogram would representation. the an determine construct which best b histogram. estimate the modal for the mean and class. solving a compare The histogram shows the lengths of a sample these of data had 15 give 9 relative mothers they Frequency 120–129 why table (years) Problem a 90 when frequency Age, 3 students were Frequency 120–129 of Zealand, they European otters. sets. y b Comment of on 14-year-old the distributions students in Sri of the Lanka heights and Peru. 10 7 The frequency nearest kg) of distribution 35 parcels is for the given masses in the (to the 9 table. 8 7 (kg) 6–8 Frequency 9–11 4 12–17 6 18–20 10 21–29 3 ycneuqerF Mass 6 5 4 12 3 a Determine b Explain the class boundaries for each class. 2 1 why histogram you for this cannot draw a frequency 0 data. x 50 60 70 Length c Copy and complete the frequency 80 90 100 (cm) density table. a Find the class interval that contains the median. Mass Frequency Class Frequency width density b (kg) d 6–8 4 3 9–11 6 3 12–17 10 6 18–20 3 3 21–29 12 9 Construct 20 8 a frequency density 6 Quantity histogram. Calculate an estimate for the mean length. S TAT I S T I C S 10 The histogram some shows customers at a the waiting times for a State the modal b Calculate A N D P R O B A B I L I T Y class. supermarket. an estimate for the mean waiting time. ytisned 2 ycneuqerF Find d Find the an total who i x 20 60 100 Waiting Review in estimate for of the customers. Twenty-ve 140 time 180 220 had to number of customers between shown in and women children the 60 and 90 seconds 260 ii (seconds) longer than 2 minutes. sustainability from Mexico were asked Number many wait: context Globalization how number 1 0 1 c they frequency Number of had. The results per children Frequency histogram. children of 0 1 2 3 4 5 4 8 5 4 5 2 are woman Use the and compare results from parts a and b to describe y the distribution of the numbers of 10 children per woman in Australia and Mexico. 9 8 2 The amount of land covered by rainforest in the 7 ycneuqerF Amazon 6 5 region the past the percentage has decades. been This rapidly frequency declining table over show 4 of deforestation for 20 South 3 American countries. 2 1 0 1 2 Number a Show that woman b A is group asked given the 25 4 0.3% 1.6% 2.1% 0.3% 2.7% 2.2% 3.5% 2.0% 9.2% 3.2% 0% 3.0% 3.3% 4.0% 0.6% 0.5% 4.0% 1.7% 2.6% 5 children number women same this Reect and How you have mean of 3 of children per 1.48. of the in 0.4% x 0 from question. Australia The results were a Sketch a frequency b Comment c Determine histogram for this data. are on the distribution. table. discuss explored the any data that could be outliers. 6 statement of inquiry? Give specic examples. Statement of Inquiry: How and quantities trends in a are represented can help to establish underlying relationships population. 6.2 City skylines 20 9 7 Measurement A method of determining quantity, capacity or dimension using a dened unit Is 10 Would always you than 100? rather ● wait ● pay ● walk 10 ● have 100 ● carry Why less 10 minutes 100 cents km 10 g or or or 100 or we 100 seconds Qua $10 10 liters do or ntity + unit = mea kg of 100 ml devised of water? standard units? systems of measurement compare quantities. and UK were based on body based on hands, forearms) or other b etween 3 miles of units dened varied the for worldwide, own make such 1 as system all time’. to was pounds some more example: be a and precisely, country. to Metric although for inch. feet, country The system units are countries idea ‘for all understood still use their systems. What are the non-standard or ● available, measurements from metric people, ● readily barleycorns Standard but were disadvantages units such as of using hands, paces barleycorns? What are standard 21 0 the advantages units? Are of there using any size 7 is 1 barleycorn objects (one-third that are barleycorn s. parts size (thumbs, sizes The Early dierence measurements shoe to still and t gold US describe men meters need Humans sure disadvantages? of an inch). 6 and How big Although units, we most is it? have people sophisticated are not very interpreting measurements. ● sofa Would a t family As in big Media such two as reports as ‘an the gives of A a blue cm comparisons the × visualizing 80 cm × 70 standard or cm size or A blue and of ‘an whale weigh as can be much up as to 200 30m long tonnes. area Belgium.’ these you blue and of 160 at and whale use of good tools car? pitches’ size Which measuring a area football twice ● a measuring the two best comparisons idea of the size whale? whale weigh as can be much as as long 33 as 9 family cars elephants. 21 1 Y es, I’m absolutely positive 7.1 Global context: Objectives ● Knowing value ● of a value of a Inquiry dierent denitions for the absolute the and sustainability questions ● What ● How is an absolute value? F number Understanding Globalization properties of the absolute C number value are the properties similar to other of absolute properties in SPIHSNOITA LER mathematics? ● How can error estimating ● How ● Can can or be measured when approximating? error best be measured? D you ever know the exact value of ameasurement? ATL Critical Draw thinking reasonable conclusions and generalizations 6.1 Statement of Inquiry: Quantities and human-made measurements systems and illustrate the relationships between communities. 7.1 7.2 21 2 N U M B E R Y ou ● should calculate already with negative know how integers 1 to: Work a c ● nd the square root of a number 2 out 4 these calculations. 6 5 × Work 3 out these b 3 + 7 d 18 ÷ −2 expressions. 2 a b 121 7 1 c d 0.01 4 ● substitute numbers positive into and negative 3 expressions When a a + a = 4 and b b = −2, b a d b 2 c Introduction F ● What is an to absolute 2 a e nd: b f a absolute ab value value? Activity °C 40 State the temperature dierence between: 1 and 30 noon sunrise noon 20 2 sunrise and sunset 3 sunrise and night 4 noon To and calculate the other. choose Here 1 is the the Reect When use we the sunrise sunrise sunrise noon and is is is is the − 10° − 10° night, 8° − 10° sunset, 15° − and calculate temperature = b, a you b or subtract b a? Or one did from you dierences: temperature rose by 17°, 17° the = = a answer? temperature rose by 5°, 5° the temperature dropped by 2°, −2° the 27° quantities always the sunset, 15° and you noon, 27° and two positive discuss about positive did a and and dierence talk between calculating dierence Between so of dierence Between so 4 the –10 gave dierence Between so 3 way the night Activity, that sunrise 0 dierence this Between 10 sunset one one so 2 In the a sunset = temperature dropped by 12°, −12° 1 dierences in real-life situations, why do we usually dierences? 7.1 Yes, I’m absolutely positive 213 After who playing had the dierence 7 points’. unusual The by The for went we The the losers it has absolute The say If up. ‘We ‘We lost had implied scored the The by context. points temperature numbers may points’. tells gives say It you you ‘We would the won be by highly points’. the 7 7 won?’ much?’ winners 7 in ‘Who how less When than dropped used are a the by always team other 20°, it loses team, obviously positive, because value. value that scores. say is question ‘By obviously absolute between to more. andnot the may the Asking two dierence 7points down use asking score. someone negative not game, between 7points, and a highest of number a number and 0. is We the distance write to on mean the number ‘the line absolute value Tip of x’. On some calculators 5 5 the x –5 –4 –3 –2 –1 0 1 2 3 4 absolute function 5 abs(x). For Using example, absolute , value and . notation, the temperature °C dierences you calculated in the Activity are: 40 1 Between sunrise and noon: 30 noon 27° − 10° = 17° = 17° 20 2 Between sunrise and sunset sunset: 10 15° − 10° = 5° sunrise = 5° night 0 3 Between 8° − 10° 4 Between sunrise = −2° noon 15° − 27° = = −12° Let x a = a = a if a ≥ = 12° 1 0, and e 2 what State your Give the –10 sunset: 12 Describe night: 2° and Exploration 1 and you ndings positive x = −a b a = 0 c f a = 3.14159 g notice as a if a about general square < root 0. Find your a a x = = for each value −5 −3.14159 h answers. rule. of: b c d e f g h State what your 21 4 you ndings notice as a about general 7 Measurement your rule. answers. a d a Describe of a = −0.003 value button is N U M B E R Denition of absolute The value is 1 rst an piecewise The denition example of function dierent has the values Reect ● Why and can’t number, ● Can number ● Can 1 Write surd take the take the , take if the ∈ value or root of the square root of a negative ? of the absolute value of any real ℝ)? absolute value of any real number? 1 down when the value of the following. Leave you answer as a simplied possible. 35 a absolute square a x 2 example: ( you Practice you for you discuss dierent of 35 b 234 c 234 d 4 e 2.8 f 5.6 g h 0 8 2 2 i 3 10 j k 36 l 4 5 3 25 m 2 Find the a 4 + 9 e 5.1 32 n value − o − 24 − p ( −10 ) of: b −2 + 5 c 3 × 6 g 12 4 d 9 9 3 7.2 f −7.5 × 2 × 10 h 5 −3 i + 8 Problem 3 4 −3 j Write two numbers b Write two calculations a highway, highway between a same safely b The is average for there driving of relative speeds −4 k × −2 −4 × −2 l have an whose too fast should answers or be absolute too no value have slow more can an of absolute cause than a 4. 20 value accidents. km/h of For 6. safe dierence speeds. section travelling that driving driving, cars’ Gauthier 8 solving a On − at to each speed the at 97 km/h. highway. on to is driving whether or at not 113 km/h they are on the driving other. a average others Nathan Determine be stretch speed, driving of highway determine safely is the 110 km/h. minimum relatively to Louis If Louis and on is maximum this stretch ofhighway. 7.1 Yes, I’m absolutely positive a denition 2 for a function. 21 5 Proper ties and applications C The of absolute value is absolute also called modulus ● How are the properties of absolute value similar to or ● How can Objective: B. ii. patter ns In describe allows mathematics? error be Investigating Exploration table in 2 you you to as measured will be estimating or approximating? patter ns general observe when r ules looking for consistent patterns. with ndings Organizing the information in a trends. ATL Exploration 1 Determine a 0.005 d = a = down Write 3 11, a d a = a = your = what ndings b − 3, = b you each down absolute 2.625 d general = pair − 6, b value. 1.001 h property. of = values a 4 and b c f as pair − 30 your a each a b a of a = general values − 2, b property. of = a and b 4 c e you an notice. 10 what be e ndings for = as for − 15 your and 3, c b = could g 7 b down Describe Write b − 0.2, Find numbers 392 and Describe real f Find a these b Write a of 5 e 2 2 which f a a = = 1, b = − 0.2, − 5 b = − 0.8 notice. ndings as a general property. 2 4 Find a a = and a for 5 b d following a = values of − 3 a: c e Describe Write 5 the Copy what down and a you notice. general complete rule this consistent with your ndings. table: a 2 2 3 Describe any generalizations that you notice. Continued 21 6 7 Measurement the the other numerical properties value on next page value. N U M B E R Write help 6 down your Copy and complete a b 8 3 6 a general rule using the last three Draw conclusions the any this table: symbols of from ≥, ≤ absolute numbers a, b ∈ the and = table. to complete these general properties: value ℝ: 1 2 3 4 5 6 7 8 Practice 2 Substitute the 1 = = 7, to 7 Proper ties a columns 9 5 For as 4 1 Use ndings you. b values for a and b a to nd the value of each expression. − 4: a a + 2b b d −2 a − b e 2b c −2 a + b 3 2 a = −5, a a + d 3a b = a + b 3b 3a f b 3: b −a + a − b − b c a + a + b + b 4 a e 3b b f a 7.1 Yes, I’m absolutely positive 21 7 3 a = 1, b = −1: a a + a a + b + b −b b − b − a − a + b a + b a + b c a b 3 d e b a Problem 4 Determine Any For and the values you height of accuracy that Would make it centimeter? Every an more but is Or accurate not as b such a for as sense than accurate a in to make it weighing it the to idea of positive certain the number. degree two You of cities accuracy. in choose actual between a kilometers, degree distance cities to the or of height. nearest kilometer? only to the nearest the a a between nearest object to to distance the is − 3 centimeters. an accurate an b made and the to − distance give is weigh weighing as to height is the meters calculate you can 8 − b length, enough’ person’s You which measure person ‘good a value. of might measurement exact b b solving measurement, example, 11 a f a to a certain nearest gram nearest or degree, milligram, to the so it and nearest is not this is centigram, microgram. 18 18 17 17 16 length The true perfect value the a describes following possible 21 8 17.4 cm length measurement measurement. Accuracy In of = This how is, close exploration, measurement as the by a is its the value nature, true 7 Measurement and value. 17.42 that not measurement example, = cm would really is to practice obtained possible the we be true use to by a obtain. value. the most accurate N U M B E R ATL Exploration 1 Measure your centimeter. 2 Now as Write height, Copy measure you 3 can, to them in the the your the the length table and height, nearest of a piece write the your length millimeter. second column of of nearest paper, your to cm piece The of of in paper, these to width the and be the of rst the an to the nearest column. width true eraser of values an for eraser these as accurately measurements. True value accurate the – most measurement nearest Absolute Relative Percentage error error error mm) height length of a piece paper The 3 the table. (to Your and measurements Consider Measurement the a of width Calculate The of the an absolute absolute error in a eraser error, error Δx, for of a each measurement measurement is the using actual this denition: amount of measurement. Δ x Write the 4 Compare 5 Calculate The size absolute the the absolute relative relative of the errors error thing in your errors. error is Write for the being table. each error in down what you measurement a notice. using measurement this denition: compared to the measured. Δ Relative 6 Write the 7 Calculate error = relative the percentage as percentage. 8 Write the 9 Compare error percentage the in percentage The a errors your error is the errors percentage in table. for each relative the errors. measurement error of a using this measurement denition: written table. Write down what you notice. 7.1 Yes, I’m absolutely positive 21 9 Example Frederico and says 1 measured that a Find b Explain a An Let x = why of Relative has true there 5% true = height Frederico Frederico’s error his to be made 132 an cm. error His of doctor 5% in his then measures him measurement. height. are two means a possible relative values error of for his true height. 0.05. Write the percentage error as a relative error. value absolute error error = Substitute into the denition. Solve for x 0.05x = 132 x or 1.05x = 132 x = 125.714 0.05x = x 132 0.95x = −132 x = 138.947 Use the same level of accuracy as Frederico’s true height is either 126 cm or 139 cm. in the question. b Absolute error measurement we would Practice does is need not above more tell or us whether below his information Frederico’s true to height know – which. 3 ‘To 1 Elias estimated 23people 2 Breanna 240.5 that attended. measured ml, 240.9 20 Find the ml, people the would percentage capacity 240.2 attend ml, of a 239.5 error mug ml, an ve evening in his In fact, Calculate the mean value for the The tr ue capacity of the mug is of the Her results mean 3 Markéta was 4 240 Amelia Find 5 you ‘To human; err to A made two factory 2%. Find 2 20 Find a this 250 the an is g an foul capacity . 240.1 pack error correct produces range acceptable of percentage 18% possible the is really ml. Calculate the percentage up you need error computer.’ result. think bought g. 1711 were: Paul Do cereal of in butter. percentage She dierence a error? weighed in mass. calculation. Her it to Take Explain. nd 250 incorrect its g actual as the answer mass true is value. $27.50. answers. bars possible with mass masses 7 Measurement to ml. a c human; divine.’ Pope, things b is Alexander but a err forgive, estimate. times. 241.2 lecture. of 58 g, cereal and percentage bars from this error up factory. to Ehrlich, 1969 N U M B E R Problem 6 Huýnh fails 500 7 to g Find ● 30 kg measured How can How do value and Which type Justify your Absolute value without Think to a websites and has the the be error before 12% or ___ g largest an Scales will absolute error error of of experiment. more. statement: percentage best lab of than percentage Huýnh that fail A scale uses a measure the 500 g a test. error. 1% 10% values useful? measured? inuence communities? error measurement. in a tool or from your These errors accuracy in either come reading it. 3 (absolute, is the absolute measured an positive births this more measuring the relative when error. or claim it When negative to give value value. absolute situations Some a or absolute error the error or percentage) is the best to use? arguments. the describe has of taking of a discuss error and that systems of science Complete with measures accuracy the ___ g with are ● in percentage than ● the a scale. less measured Reect ● each as scales has measurement kg Absolute ● the it When D ● if test the 500 all test mass ● from tests the mass solving of Could the you dierence measure between the the absolute true error value? would is it be better important not to to use know the absolute whether the value error value? the true world population, plus the number of The deaths so far that year, so naturally this population number world’s is population changing constantly. If the population gure varied between 7 379 930 858 is 7 379 930 871 over a one-minute for population? period, what would be a good 47 people world Could anyone ever know the exact value of kilometer. the The world most densely population? populated is Reect and discuss 4 Why do we often use people approximations instead of exact amounts? Is per appropriate to use If you you 0.01 ● Is it measure can still mm. a length make Can important you to approximations? measurement a know How help you the is approximations? to more ever 16 205 populated Mongolia ● at square it least always country Monaco kilometer; ● per approximation square the density and the nearest exact know exact can and measurement the exact values, knowing decide cm or length can the whether to of you size an then of to the the nearest exact 0.1 mm, mm square with 2 or something? always the use error in approximation a is acceptable? 7.1 Yes, I’m absolutely positive per kilometer. 2 21 Summary The on absolute the value number means ‘the line of a number between absolute value 5 is that of the distance number and 0. x’. –4 –3 –2 –1 0 1 2 true that would to 3 4 the The example, Properties of any a measurement describes by how a is the perfect close a value measurement. measurement is absolute Δx, error, Δx amount of error of in a a measurement is the measurement. = value The For of obtained 5 and absolute be truevalue. actual For value Accuracy 5 x –5 The relative error is the error in a measurement ℝ: numbers compared to the size of the thing being measured. Δ 1 2 3 4 Relative The error percentage measurement 5 6 7 8 Mixed 1 Find a − error is written the as a relative error of a percentage. practice the value of these expressions. − b 33 c = 2 7.8 ( f bought 3 measured it, of Find 3 5 e Soraya she meters found of ribbon. there When were 3.15 she meters 4 − 6.5 12.3 d −2.3 + 8.05 4 5 ribbon. meter Moa the percentage error in the measurement. charges €10 to iron 8 shirts. On average, 2) 9 she g 27 Find the − h − 81 irons value of these shirts a Determine b Determine c On 20 2 8 per how hour. much she charges to iron shirts. expressions. her average hourly rate. 2 a 4 × b −5 − − ( −6 ) Monday, and c d i 12 ironed She 20 shirts charged the in 2 hours customer €25. Determine ii − Moa’s hourly rate for these shirts. 6 2 1 9 − 12 8 the percentage her average her hourly hourly dierence rate (in between part b) and 5 15 56 g Find 144 × f × 5 × −3 d On Friday, rate she for took 3 these hours shirts. and 12 minutes h 7.2 4 8 − 6.25 × 7 − 3 to iron 20 shirts. dierence 3 Moa minutes. 27 6 e 15 The exact length of a bent stick is 22.2 cm. length his to it with a straight be 21.5 cm. Find ruler the and estimated percentage between the her percentage average error part b) and her hourly rate 7 Measurement for its of Which rate is the Which one is an exact rate? estimate. 2 2 2 hourly rate Daniel (in measured Find estimate? these shirts. N U M B E R Review in context Globalization 1 The most recent and sustainability census in China was in July2015 2 UK and the population government was statistics In two be 1 376 049 000 separate a Calculate reported to be articles, in 1 376 048 943. this gure population was a quoted million 1.38 absolute error in each of compared to the ocial Calculate the Discuss percentage whether it is Find the Find the Government reliability gure of may Calculate e sources the be better the way to suggest it is use absolute this is possible that, due measured, inaccurate what Calculate Discuss to what report Here are In by as plus an range or the the given might be a population the reliable of populations in States in population. half a error in the headline million. 17.7% over. of d error. e population. gure some 2013 the the population percentage were was aged 65 17.4%. Find the aged 65 actual and change to over in the between number 2013 and of people 2014. 1.8%. Is this gure Suggest an how increase these or gures healthcare in the a decrease? could be useful for UK. use China. of In 3 Tobias went grocery roommate shopping Felix. They for himself usually split and the cost countries, groceries in half, and since they never have change, they usually round the amount paid before paid exactly splitting it in half. Today, Tobias 80 688 545 €95.74, and he rounded the amount 30 331 007 Australia to an even €100 before telling Felix that he 23 968 973 owed Monaco Tobias €50. 37 731 a gures could also be inaccurate by Calculate absolute errors. Use these to the percentage error between the 1.8%, true the change the up nd rose 321 442 019 Malaysia the population 2015: Germany If UK 64 510 376. percentage of 2014, exact United the ocial minus absolute for to the of also 2014 or his g to exact planning f and errors. and d year errors. c percentage 2013 64 106 779 gure c a gure. b b in these a gures half billion. from the by to Between and grows ocial amount Tobias paid and the rounded give amount. reliable values to quote for these populations, b and justify why the values are Discuss whether Felix pay c to Calculate have and and How you specic exact reimbursed what error he explored the statement of is reasonable for amount Tobias. Then between should Felix what have should calculate Felix did Discuss paid. what you errors. notice about Would it the have two made sense examples. to just calculate absolute errors in this case? Statement of Inquiry: Quantities and human-made the pay inquiry? percentage Give it discuss d have not €50. the percentage Reect or reliable. measurements systems and illustrate the relationships between communities. 7.1 Yes, I’m absolutely positive 2 23 How do they measure up? 7.2 Global context: Objectives ● Converting metric SPIHSNOITA LER ● Converting ● Using ● Solving units Inquiry between units of area metric and between metric correctly problems units, in and F imperial problem involving Deciding is ATL Use ● including volume units ● compound the answer to a ● problem sustainability questions What are How do volume D if and the dierent systems of measurement? C solving measures ● Globalization Should of ● we into we convert measures dierent adopt a of area and units? single global system measurement? How do systems inuence communities? reasonable Communication intercultural understanding to interpret communication 6.1 Statement of Inquiry: Quantities and human-made measurements systems and illustrate the relationships between communities. 7.1 7.2 2 24 N U M B E R Y ou ● should recognize and already units for know length, how mass 1 to: Group volume these lengths, measurements masses Which is the 2 kg 34 9 km and odd mm one 15 into volumes. out? g 24 s 5 ml 3 ● write powers of ten in full 2 13 Write in miles down these 3 multiply of and divide by powers 3 of cm ten b 2 10 c 10 Calculate. ten 2 nd the area of a square 4 280 nd of a the sur face area and volume × 0.001 Calculate side ● 8.4 powers 6 10 a ● liters full. a ● 6 5 the length b area 12 34 500 of a ÷ 10 square with cm. A cuboid measures 3 m × 4 m × 5 m. cuboid Calculate its sur face area and volume. Units F ● for What are Exploration 1 Add of. ● ● to this Group the dierent systems by writing similar units down all measurement? per the of measurement you can think Think ● hour units together. (kg) kilometers of 1 list kilograms measurement minutes ● (km/h) degrees you (min) of use your list with others. Did anyone (°) group units Add ● to this list all the ● length types of measurement ● volume you can think length and distance the same measurement? What about travelling, is one about words how volume capacity? Compare it etc. volume and 3 and cooking, mass the and in of. Think Are in dierently? when 2 units mathematics science, Compare the used your for. two Are lists. there Match any each types of unit to the type measurement of that measurement have ● Does ● Why each ● Can and every are used. (1D, only unit? Reect capacity discuss units often measure have dierent more what 3D) space does refer? 1 measurement there To 2D, are than units? units one Explain for a type single of why type this of is the case. measurement? measurement? Explain fully. 7.2 How do they measure up? 2 25 Practice 1 Suggest 1 sensible units for these specic measurements. The a A matchbox measures 40 × 25 × ‘A’ series 12 of b The length of an A4 sheet of paper is 297 c The length of an A4 sheet of paper is 29.7 paper used sizes Only the Canada d A shoebox has a capacity of to e A shipping f The oor g The length container measures US do currently 6307 6.06 × 2.44 × the of a house is standard 2.59 Mexico, 250 in a swimming pool is Select appropriate units for Chile 50 and 2 practice Venezuela, Colombia, of and not conform ISO although area is worldwide. these. the favour Philippines the US letter format. a The weight b The dimensions c The area d The speed e The height f The dimensions g The speed Systems of of of a a farm of wall of an of of a a a tractor tennis in a court house ambulance girae of a piece javelin, of when land thrown by an athlete The measurement International System The two most widely used systems of measurement are the metric system of Units and (abbreviated the imperial SI system. from the French ‘Le Système International A system units. All of measurement other units in is the a system system are of measures derived based from the on base a set of base units. d’Unités’) ocially came being the The metric into 11th Conference system Weights The metric system is used widely in Europe and most of the rest of the world. October ● International meter (m) for System of measuring Units (or SI) denes seven base length kilogram ● second (kg) for measuring The French the for measuring time ampere (A) for measuring the Kelvin ● mole (K) (mol) for for measuring measuring electric even candela (cd) for amounts the of a intensity substance 10 days 10 hours of with in a in week, a day, in an light. in a and 100seconds minute. returned to They traditional timekeeping 7 Measurement to time temperature hour 2 2 6 1793 current thermodynamic measuring In tried 100minutes ● system French decimalize ● in brought metric Revolution. they ● Paris mass after (s) in 1960. units: in ● on and Measures The at General in 1806. N U M B E R All other the unit units are derived from these and are called derived units. For example, In of speed, in terms of the base units, is some books, m/s m/s. 1 is The SI which (or act metric as system) multipliers. allows The other unit units prexes to be specify created a by power of using written ms prexes ten: 3 ● a kilometer is 10 times larger than a meter (standard unit), 3 1 km = 1 × 10 m a nanosecond 5 nanoseconds = 1000 m −9 ● is 10 times smaller than a second (standard unit), −9 Dividing ● a by gram the = 5 factor (standard × 10 seconds allows unit) you is to = 0.000 000 005 convert smaller than a a seconds. standard unit into another unit: kilogram, 3 500 ● a g = meter 500 g ÷ 10 (standard = 0.5 unit) is kg larger than a micrometer, −6 1 m = 1 m ÷ 10 Prex = 1 000 000 Letter m Power Some derived units 12 tera- T 10 are a 9 giga- G 10 mega- M 10 named person after closely associated with 6 them. For example, 3 kilo- k 10 deci- d 10 centi- c 10 milli- m 10 micro- μ 10 nano- n 10 the 1 Newton ameasure (N) of is force. 2 1 2 N = 1 kg m/s 3 6 9 Practice 1 Find 2 these a 3.5 c 257 conversions. megatonnes mm to to tonnes meters b 8 gigabytes d 6.5 dl to to bytes liters ‘How many millimeters 2 How meter’ a c are in a many: nanoseconds watts are in a are in a second kilowatt b d micrometers centiliters are are in in a a meter is the same as ‘Convert to millimeters’. meters liter? 7.2 How do they measure up? 2 27 3 Find these conversions. Tip a 2 m to c 2500 μm watts to microwatts b 3.2 g to mg d 0.5 seconds to nanoseconds Check that answer 4 Find these conversions. sense. a 285 cm = _____ m b 923.5 mg = _____ Should converted g smaller c 4358 e 7.263 g 18 655 i 0.05 your makes m = _____ km d 4358 m cg f 12.45 l h 560 j 380 506 = _____ = ______ l = _____ or be larger mm than kg the unit the original cl unit? ml km = = _____ Problem 5 A 5 human μm _____ cm mm = _____ mg = cm _____ kg solving ovum across. has diameter Calculate how 0.1 mm. many The times head larger of the a human ovum is sperm is compared roughly to the sperm. 6 The 1 cells μm. of How microscope the bacterium many of Staphylococcus these cells could t aureus on a are spheres rectangular 75 with mm diameter by 25 mm slide? 1 μm On cell the same 1 area length The imperial imperial other 1 system is now chiey used in the US (US customary and many systems measures paces μm. of measurement had their own standard on are which were based. Small distances were counted in number (yards) and larger distances in miles (1000 paces). Capacity and using kitchen Eventually a items, such standard was as cups, set so because that all it was mainly measurements used were units, in the they both from everyone. same Reect ● What as ● and diculties paces What discuss and types might SI (or measures of For metric) are example, problems 2 2 8 arisen in measuring with units such yard in ≡ might have occurred from the use of units? standards dened 1 have cups? non-standardized The 2 are terms 0.9144 of now that meters, 7 Measurement accepted worldwide and all other standard. where ≡ means ‘is equivalent to’. are same derived for US was but cooking. between of customary measured a side units). imperial feet as with dierences the each the system There Originally, up μm square The slide, takes system. the N U M B E R Some conversions marked and * are Pound for exact; metric all dened km 0.625 1 m 1 kg 1 liter 1.76 1 liter 2.113 39.4 2.205 1999, metric the Mars units Mars, for mile be are shown exact by in the the tables. Those International Yard pints mile 1.609 km 1 foot 30.48 1 inch 2.54 1 ounce (oz) 1 gallon (UK) 4.546 liters 1 gallon (US) 3.785 liters cm (*) Orbiter contractor such it crucial is cm (*) (lbs) 28.35 g (US) Climate where 1 (UK) pints a Metric inches pounds while measurements to units to Imperial Imperial 1 close imperial are Agreement. Metric In and others was used lost imperial calculations thought because to have units. caused been the NASA Failing the to probe destroyed by team used convert to come the the too planet’s atmosphere. Example Find a 8 b these UK 13 1 conversions. gallons liters to to UK liters gallons × 4.5 1 a UK gallon ≃ 4.5 liters 1 UK gallon 8 × 4.5 = 36 To liters 1 b 13 ÷ 4.5 = 2.888… ≈ 2.9 convert UK gallons (1 4.5 liters gallons gallon ÷ Use UK ≃ UK the ≃ 4.5 to liters, multiply by 4.5. liters 4.5 inverse operation. d.p.) To convert liters to UK gallons, divide by 4.5. Round Objective: iv. In justify Practice 3, Practice 1 Find D. the Applying degree justify of the mathematics accuracy degree of of a in real-life to a sensible degree of accuracy. contexts solution accuracy of each of your solutions. 3 these conversions. a 1 inch≃ ___ c 1 pound ≃ e 1 UK pint m ____ ≃ kg ____ liters b 1 g ≃ d 1 liter f 1 cm ____ ≃ = ounces ____ ___ gallons (UK) feet 7.2 How do they measure up? 2 2 9 2 Find how many: a kilometers c pounds is 50 miles b miles is 50 kilometers d centimeters For is 70 kilograms is 6 2h, convert e centimeters is g UK 2 pints is Problem 3 4 Determine 58 miles c 50 cl e 6 In This in model or is of intended a By or 1983, due of a to fuel a for One the b of Find ● each oz f 6 ft members stage the of megalith 5 UK pints is 1 a ctional (large kg mile or or rock standing pair. or 60 100 180 lbs g cm group asked stone). The height to would that an appropriate have measure they been of for an model 18-inch was measure, determine members should eective. length intended metric the to use of fuel band the model on a Canada of of fuel between journey. jet have fuel been 0.803 has a many How has a per mass and a 1.77 your liters short convert kg. conversion fuel of live in The fuel through plane have stage. of in its journey needed already Calculate answer pounds). of tell liters 0.803 your answer halfway kilograms. 7682 of Give Give we out were liter, of units do pounds loaded. kg ran There mass loaded. how ight how in the much 22 300 kg tanks. fuel liters. 1.77 Calculate was how used. much (One fuel liter was liters. the plane was. us measures of area and volume into dierent units? ATL Exploration 1 The diagram length 100 2 shows a square with side length 1 m and a square with mc 1 001 m a Explain b Calculate why the these area two of m squares each 100 have cm the same area. square. Continued 23 0 side cm. 1 7 Measurement miles kilometers. show. imperial Air What C for 4 given the actually c is solving liter jet largest d model mix-up Instead is pint Tap, what an should centimeters 25 their for, for h b Stonehenge Problem In measurement cm Spinal Decide liters km converting asked 5 72 UK 20 whether b f solving 1 a feet gallons which a or 3 rst inches on next page to N U M B E R c Copy and complete: 2 1 d 2 m = ____ cm Sketch a square with side length 1 cm and a square with side length 10 mm. 2 How do you 2 to Sketch a cm cube a Calculate b Copy c 2 to mm with the and = Work side length volume of 1 each m and a How do you convert from cube with side length 100 cm. cube. complete: ____ out cm the length volume 10 of a cube with side How do you 3 length 1 cm and a cube with mm. 3 d ? 3 m side cm ? 3 1 from 2 mm 2 convert convert from cm 3 to mm ? How do you convert from 3 mm to cm ? Volume is generally 3 measured Capacity refers to the amount of space available to hold refers to the amount of space actually cm , something. and Volume in capacity in occupied. liters. 3 1 cm = 1 ml 3 1000 ATL Practice 1 Find these 20 c 5000 = 1 liters conversions. 2 a cm 4 cm 2 to 2 mm b 600 d 4.5 mm 2 to cm For 2 cm 2 to 2 m m Q1f, convert 2 to cm 2 m 2 to cm then to 2 2 e 2 2.9 Find cm these 2 to mm f 0.7 m b 5000 d 3 f 10 mm 2 to mm conversions. 3 m 2 3 a 40 to c 2 400 000 e 2.5 3 cm mm 3 to For cm Q2f, rst 3 convert 3 cm 3 to cm 3 liters to to A 4 a piece 1 of decimeter Copy and has dm volume (dm) m to liters = 10 500 cm Find c A Find its volume in m cm 3 = ____ cm 3 b 3 . complete: 3 1 the number of dm 3 in 1 m . 3 5 Find with removal the an Suggest 1 liter truck capacity average Problem 6 has in a capacity liters depth of of a 2.15 of 6 m swimming . 3 Find pool its that capacity in measures dm 33 m × 16 m, m. solving suitable of cm 3 cm foam 3 to ml 3 3 m 3 m dimensions for a cuboid-shaped carton designed to hold juice. 7.2 How do they measure up? 2 31 Exploration A cuboid is 30 3 cm tall, 50 cm long and 1 m wide. mc 03 1 50 m cm 3 1 a Use the lengths in cm b Use the lengths in m c Show a Calculate b Use to calculate the volume of the cuboid in cm 3 that your two to calculate results are the volume of the cuboid in m equal. 2 2 the surface area of the cuboid in cm 2 3 A box step in a the to nd shape the of a surface cuboid area is of 250 the cm cuboid tall, 472 in m cm long and 545 cm 3 wide. Calculate Reect In and Exploration ● Which of the volume discuss of this cuboid in m 3 3: units rst the would cuboid? you use Which to calculate units would the you surface use to area give and the volume nal answers? 3 ● Option 1: Convert Find the the volume dimensions to in cm 3 , and meters, convert then nd to the m . Option volume. 2: Which is the 3 easiest ATL way Practice to nd the volume of the box in m ? 5 2 1 The 2 A dimensions of a tennis court are 2377 cm × 8.23 m. Find its area 2 soccer Which 3 A eld measures measure container has is 0.110 easier length to km × 73 m. Find its area in m in m 2 and in km visualize? 9750 mm, width 6400 mm and height 5640 mm. 2 a Find its oor area b Find its volume in m 3 Problem in m solving 2 4 1 hectare (ha) is the area of a square 10 000 m 2 A square Find You units the can of eld area use area 232 the and has of an the area eld of in 0.36 km hectares. imperial-to-metric volume. 7 Measurement conversion factors for lengths to convert N U M B E R Example 2 3 Find Use the the 1 inch 1 yard number of cubic conversions: = 2.54 1 meters inch = (m 2.54 ) in cm, 10 1 cubic yard = yards. 36 inches cm Write 10 = 36 yards = 36 inches × 10 = 360 inches the conversions. then centimeters. inches Convert 360 down inches = 2.54 10 yards = 9.144 10 cubic yards cm × 360 = 914.4 yards m to inches, Convert 3 = 10 cm (10 10 yards to meters. 3 yards) = (9.144 m) = 764.554… Check that the answer makes sense: 10 yards 3 10 cubic yards = 764.55 m (to 2 d.p.) is shorter than 10 m (10 yards = 9.144 m) so 3 10 Practice 1 A cubic yards should be smaller than (10 m) 6 rectangular piece of land a Find the dimensions b Find the area a A of the of is 2 the land km piece in long of square and land 3 in km wide. miles. miles. 3 2 box measures 4 in × 5 in × 6 in. Find i its volume in cm , and 2 ii its surface area in cm 3 b Another box measures 3 in × 5 in × 8 in. Find i its volume in cm , and 2 ii its Write surface down area what in you cm notice about your answers to parts a and b 3 3 Find the number of cubic centimeters 4 Find the number of square 5 A truck 6 A cube (cm ) in 5 cubic inches. 1 yard = 0.9144 2 meters (m ) in 10 square yards. 3 has a capacity of 25 m . Find the capacity of the truck in cubic feet. 3 has volume in . a Find the side length of the b Find the side length in cm. Problem 7 64 A dressage cube in inches. solving arena for horse riding is a rectangle twice as long as it is wide. 2 Its area is 8611.13 Converting Compound be . Find compound measures measured When ft in per length more second measures in meters. measures involve meters compound its are than and one unit. density involved, you in For example, grams may per need to speed cubic can centimeter. convert both units. 7.2 How do they measure up? 23 3 m Density is the mass of substance contained in a certain volume. The 3 density is of solids measured Example in and liquids is measured in g/cm , and the density 1 kg density = 1000 of iron is 7.87 g/cm . 3 Find the density of iron in kg/m g Write 3 1 m gases 3 3 The of g/l. down the conversions you will need. 3 = 1 000 000 cm 3 Method 1: 3 7.87 g/cm convert g/cm Now convert g/m 3 to g/m 3 × 1 000 000 = 7 870 000 3 7 870 000 First g/m g/m 3 3 ÷ 1000 = 7870 kg/m 3 to kg/m Method 2: Write the fraction conversion and factor for volume as a multiply. Multiplying by multiplying by is equivalent to 3 1, since 1 000 000 cm 3 = 1 m . 3 The cm units Write as a The In speed some Which 1 mile = limit and by multiplying by time, the factor is 1, for mass multiply. since grams equivalent 1 kg = to 1000 g. cancel. on of motorways Europe, the in the speed UK limit is is 70 110 miles per hour kilometers per (mph). hour (km/h). faster? 1.609 70 mph × 70 mph is 234 conversion 4 parts is the fraction Multiplying This Example cancel. km 1.609 faster = Write 112.63 than 110 km/h km/h. 7 Measurement Convert 70 down miles the per conversion hour to you will kilometers need. per hour. N U M B E R Practice 1 7 Convert hour a 2 these speeds from kilometers per hour (km/h) to meters per (m/h). 10 km/h Convert b these 54 speeds km/h from c meters per 4.8 hour km/h (m/h) d to meters 280 per km/h second (m/s). For a 3600 m/h b 43 200 m/h c 9000 m/h d 2160 Q2, convert 3 Oliver 4 A sea is driving turtle can at 65 swim km/h. at a Find speed his of 2 speed m/s. in Aluminium has 6 Oxygen a has Problem density density 2.70 of g/cm Find its speed in km/h. 1.43 g/l. Find Find its its density density in in 3 Lead has density 11.34 g/cm 8 Gold has density 19.32 g/cm 9 The speed limit Europe. Are Problem A 11 cat reached Oxygen minute, of per has in urban these Find the mass of 1 Find the mass of 0.5 is 1 to hour m of lead. is the 30 mph same? in the Explain m US, of and your gold. 50 km/h in most answer. can reach top speed a density a of of top speed 12.27 1.43 of m/s. g/l. 48 km/h. Determine Enzo says that The sprinter which 120 cl is of Usain Bolt faster. Tip oxygen has a grams. Justify whether or not he is of a correct. travelling travel at 110 a speed km. of Justify 25 m/s. whether He or claims not he that is it will take him can tell do: mean Problem 1997, the a car distance solving world Thrust speed sound a of what will divided In measure you correct. to 13 to 3 . areas speeds a 17.16 Timeo then second 3 . compound 12 meters kg/m Units mass to solving domestic has per mg/cl. 3 10 hour solving 7 of per meters 3 . meters m/s. 3 5 rst m/h SSC. about barrier. land-speed The 340 sound meters Explain record your of barrier per 763.035 is miles reached second. per when Determine if hour an was object Thrust set moves SSC by time. by broke at the answer. More conversions and units D ● Should ● How we do adopt systems a single global inuence system of measurement? communities? Conversions Activity 1 Euro (EUR) 1 USD = = 0.996 Swiss 1 Convert 650 2 Convert 1800 3 Calculate an 1.10 EUR US Dollar Franc into CHF (USD) (CHF) USD. into USD. approximate value of 900 CHF in EUR. 7.2 How do they measure up? 23 5 Reect ● How and is the process converting and ● a from currency Quantity as discuss is of unit. conversion Research b Which c What to units what systems are do from one another? amount or with to to measurement? the similar unit fully. or do to conversions Measurement capacity more another both Explain number. quantity, conversion unit Are dimension with Explain is dened using quantity, a and unit fully. 4 natural Determine an currency more a as to standardized? determining Is Exploration 1 converting currency conversions dened method dened of one 4 the and answer natural of units natural advantages questions. are. units of these are the used? natural system of units? Are there any disadvantages? 2 Systems denes man-made unit. a Determine b Decide Reect ● Is ● Why ● What the is If a a units the a would prototype natural man-made no be single the need a prototype, measurements discuss there unit is are for needs that compared the a is, to an the object that prototype. kilogram. prototype. 5 unit or global natural system advantages and unit? of measurement? disadvantages of having a single measurement? single chosen? Some what and of Other whether day system ● of a system Explain unusual ● The Hand ● The Board ● The Shake ● The Foe units (= 4 foot (= of measurement of measurement inches) (= 10 was to be adopted, which should be fully. 1 for inch include: measuring × 1 foot nanoseconds) × for 1 the foot) height for referring of a horse measuring to very lumber short periods oftime 44 (= produced 23 6 10 when joules) a star for goes measuring supernova 7 Measurement the enormous amount of energy N U M B E R Summary A system based on system of a measurement set are of base derived is units. from a system All the other base of measures units in the units. Capacity to hold of space refers to the something. actually amount Volume occupied. of space refers Both to available the amount capacity and 3 volume The two most common systems of can be measured 3 the metric system and the imperial metric system allows other cm using unit prexes, prex which species a act as power units to be multipliers. of ten; liters: 3 = 1 ml, for 1000 cm = 1 liter. measures such as speed and density created combine by and system. Compound The cm measurement 1 are in measures of two quantities. Each example, Density is the mass of substance contained in a 3 the prex kilo- species 10 certain Some common conversions: 2 To convert from m 2 to cm , 2 To convert from mm To convert from m to Mixed 1 a b 3 the a use cm cm of to the capacity d the weight cm the amount f the distance a 3 to b 4.8 c 760 d 9845 e 0.01 f 400 600 kg of by by 100. 1 000 000. The in density g/cm ; , divide by 4 b 15 solids and density of liquids gases is is measured measured in g/l. 1000. measurement you 4 a a of in a swimming storage box m km these 9500 c 0.5 d 6400 e 10 in cm mg to a cake Chicago to f Los Angeles 5 m m ≃ ≃ kg ___ ≃ d 6 liters e 10 f 800 UK g ___ ≃ 3 to cm to ml Find m to these liters conversions. a 950 meters b 36 km/h c 10 meters d 7200 e 54 to to to hour (m/h) to km/h m/h per m/h km/h per second (m/s) to m/h m/s m/s 6 A bottle ___ solving contains Calculate the from 240 number cl of of medicine. 25 ml doses that can it. g The table gives the heights and weights of cm people. feet ___ pints ≃ mm mm cm 100 two 8 m 2 to Problem 7 c to 3 conversions. inches 2 cm km to ounces mm 3 m to b 2 to cm 3 g to 50 2 person from a speed our conversions. 2 cm cm these pool conversions. to Find poured a of the 2 water of of e these unit walking c Find divide multiply measure: volume m , 3 , 3 mm which to person’s Find 10 000. practice Determine would 2 from by 3 to 3 convert multiply 2 3 To volume. ___ UK ≃ Height Weight 190 gallons ___ Person A 6 ft 2 Person B 1.82 in lbs gallons m 90 kg pounds a Who is taller? b Who 7.2 How do they measure up? is heavier? 237 be 2 8 An airline’s SIZE: hold length + baggage width + allowances height must 12 are: be A square 275 has area 2323.24 ft less Find than eld the side length of the eld in meters. cm. 3 13 WEIGHT: free up to 20 kg. Each extra kg The density of nickel is 8900 kg/m (or 3 part a of Jo’s a kg) is charged suitcase at measures 13 18 Find Euros. in × 22 take it as in × 8 the density whether he can hold nickel in g/cm in. Problem Decide of solving luggage. 3 14 b Suzanne’s bag weighs 48 lbs. Calculate Platinum she would have to pay to take it has a A 21 450 kg/m of 19.32 . g/cm which metal is denser. baggage. water tank has length 2250 mm, A car mm and height 3860 mm. travels Calculate limit of the tank Find number in is 20 50 m/s in km/h. a village where Determine if the the car is the exceeding capacity at width speed 5800 of as 15 9 density density Determine hold a 3 Gold much has how the speed limit. liters. 16 A top speed of 231.523 mph was set by a 3 10 the of cubic inches in 9 cm Formula 11 Find the number helicopter of 2 m in 6 square 1 1 in = 1 yd 2.54 racing has in in 2005. maximum A Chinook speed of 87.5 m/s. cm yards. Determine Review a car = 36 which is faster. inches context Globalization and sustainability 3 b Carbon of steel carbon is steel used has a for the mass main of cables. about 7.85 1 cm g. 3 Find c the When was density the built, of carbon bridge yards concrete After was the yard = 0.9144 m of was used. original replaced, Calculate inkg/m 389 000 1 cubic steel the concrete there total was roadway 6.4% quantity less of deck concrete. concrete in the 3 refurbished d 1 The Golden opened a for Below Find Gate vehicular are the Bridge some in trac facts equivalent San in Francisco A bolt the of diameter about the ii Each of are measurements the 746 two feet main in The total main 23 8 length cables is of tall. cables wire 80 000 inches was used in i Find the ii Imagine used miles. 7 Measurement diameter of the bolt in mm. is 7 650 in that a bolt of diameter 2.125 cm metric long. iii 2.125 bridge. mistakenly inmm. towers m 1937. units. The in construction. was i bridge both feet used. Calculate the error N U M B E R 2 Railway tracks dierent gauges a in dierent (spacing Approximately today use the 60% countries between of the standard have the rails). world’s gauge, railways which is 1 4 ft 8 in. Find this measurement in metric 2 units, b correct Originally, gauge was as nearest trains transport the the gauge trains mm. used trains. for run a 4 ft Half 8 passenger more in an inch trains, smoothly on curves. the metric Find length units, the sizes, iii to made Find ii the English coal added this the i for to in to of the the dierence coal-mining nearest gauge in mm. between the two gauge mm. Determine whether your answer in 1 part ii corresponds in. to If not, nd the 2 percentage c Some countries isexactly in d 1000 imperial Until and error. units, 2011, France Suggest tracks used meter Find feet used the Spain and a gauge, this which measurement inches. 1668 standard modied mm gauge, gauge. its railway engines. Reect and How you have the in Spain why and use mm. discuss explored the statement of inquiry? Give specic examples. Statement of Inquiry: Quantities and human-made measurements systems and illustrate the relationships between communities. 7.2 How do they measure up? 23 9 Going around and around 7.3 Global context: Personal and cultural expression Objectives ● Knowing and the Inquiry terms chord, SPIHSNOITA LER Finding the length ● Finding the angle ● Finding the perimeter ● a Use of in an a arc of sector and a of area the the a of a can you dierent nd parts the of a measurements for circle? of a ● How ● Is are the parts of a circle related? C circle sector D length How circle circle Finding ATL ● segment F ● of arc, sector questions it advantageous to generate your own formulae? chord Communication and interpret a range of discipline-specic terms and symbols 7.3 9.1 E9.1 Statement of Inquiry: Generalizing construction 24 0 relationships and analysis between of measurements activities for ritual enables and play. the G E O M E T R Y Y ou ● should nd the using ● nd C already circumference = the 2π r area of a how circle 1 πd or of know a circle using 2 to: Find the a of radius circumference b of diameter Give your Find the 2.4 5.75 answers area of a circle: cm of m. to the 1 d.p. two circles 2 A ● = r nd above. missing lengths right-angled in triangle trigonometric a 3 using Find Give the your missing answers length x to in 1 d.p. this triangle. ratios 5 cm x 30° Par ts F ● How of can a circle you nd the measurements for the dierent parts of acircle? ATL Activity 1 Match ● A each denition diameter is a with chord a part that of the passes circle. F through E the center of a circle. O C ● A chord on a is a line segment with its D endpoints circle. B A ● A secant two is a line that intersects a circle at G points. T ● A tangent only 2 Match one the is a line that touches a circle at point. following denitions with A the parts The of major the circle segment in is the the diagram. X larger W segment. The Z minor segment is the smaller Y segment. the (‘Segment’ minor usually refers to segment.) B The larger arc The smaller is arc the is major the arc. minor arc 7.3 Going around and around 241 A sector radii. is The a ‘slice’ center of of a a circle circle between is usually two labelled B radius O, so the sector here is BOC. ‘Sector’ usually minor means the minor minor major sector. O arc sector sector Lorenzo Mascheroni radius C proved that any you can with ATL and Reect and discuss in a 1797 point construct compass ruler can constructed How are secants and chords similar? How are they dierent? just a with compass. was then that George Mohr, Exploration be 1 a It discovered Danish 1 mathematician, 1 Use a set mark its of compasses center. diameter of the Draw to a draw chord a circle. that is Clearly not had the this circle. is O already in 1672 known as proven so it the Mohr–Mascheroni 2 Draw radii from the center of the circle to each theorem. endpoint triangle 3 Use a the you chord. have protractor sector 4 of Draw you a have line Determine which type of drawn. to measure the angle of the drawn. segment Tip from the center of the O circle, a O, to Explain ● the midpoint why divides this the line of the chord, Use M segment: triangle in half M ● divides the (measure angle to of check the that sector it in half does). O b Calculate segment In a the circle, center two of the angle makes radii the that with and circle a to the the chord the new chord. line Measure form midpoint an of to check. isosceles the triangle. chord forms A two line from right-angled triangles. When the you know right-angled 24 2 the angle triangles at to the nd center, the 7 Measurement you length can of the use trigonometry chord. in one of symmetry. G E O M E T R Y Example Find the 1 length of chord XY. 6 X cm 30° Y 6 cm X 6 cm a Divide the isosceles triangle 15° into two right-angled triangles. Y sin 15° a XY is = = 6 = 1.5529… 1 sin 1.5529… Practice Give × your Find 15° × 2 = 3.11 m (3 s.f.) The length of the chord is twice the length of a 1 answers the cm length to of 1 decimal chord place. JK 2 Find the J length of LM L 6 10 chord cm cm 126° 135° M K Problem solving Tip A 3 The sector Find the AOB length is of one third chord of the circle. First AB 7 of cm nd the the angle sector. O B 7.3 Going around and around 24 3 4 POQ is sector Find a is sector 75°. the of a circle. Chord radius of PQ the The has angle length 8 of the The cm. Mesopotamians used circle. O a sexagesimal system, base that 60. We is, use 75° this 8 cm today when measuring time– Q 5 ROS is a sector of a circle of radius 5 cm. P 60 Chord RS is 8 cm. Find of sector in a the minute, S angle seconds ORS 8 60 minutes cm in 5 cm an hour angles – – and 360° = R 5 cm 60× 6. O C Relationships in ● a 2 How Draw a Label the Draw radii center are 3 By circle of drawing Explain When will a To the fraction 2 the central the set of a circle related? compasses center segment show the the the angle that formula pizza, of a changes describe 1 of and then draw a chord each endpoint that is not the diameter of the circle. c line to your a parts of the circle to of the chord. Indicate the angle, θ, in the sector. what sharing be. with from the that the 2 chord trigonometry Verify measurements circle Exploration 1 between from the works you of for would more size the a center relationship of questions have to equal slices pizza slice the 1, make you you circle between 2 and to cut, to r 3 your the could θ, the and in c midpoint can be Practice formula smaller the chord as θ c, = use 2arcsin ( ). 1. for each of expressed questions 4 and 5 in Practice 1. slice measure: pizza θ (angle at the center sector of the sector), measure of sometimes the called the sector central 3 the length of the 4 the perimeter crust, or arc length, angle l ‘You of the sector, pizza 5 the area of the sector, better A arc length in because enough four I’m to Lawrence 24 4 cut the P 7 Measurement pieces not eat Peter hungry six.’ “Yogi” Berra G E O M E T R Y Objective: B. ii. patter ns In describe this Investigating Exploration between the as you dierent patter ns general will r ules search for measurements in consistent patterns a and with ndings generalize the relationships circle. ATL Exploration In this 3 Exploration you will generalize the relationship between the measurements. sector For a pizza of radius r cut into four equal slices or sectors: r 1 State the fraction 2 State the central 3 What fraction of of each sector? of each sector. of the angle the pizza for in each each sector. circumference Write down an sector. is the arc expression for length the arc length When answering questions 4 Describe of a how sector. you Write can use down the an arc length expression of for a the sector to nd perimeter of the the perimeter each length and sector. What fraction of the area of the circle is the area of each an expression for the area of each Copy and complete Number the include 1 of units. Sector Central angle sectors (the the sector. table. Fraction equal should sector? appropriate 6 arcs your answer always Write of sectors, nal 5 about Arc length Sector area perimeter whole 360° circle) 2 3 4 60° 12° 10° 9° n 360/θ 7.3 Going around and around 24 5 Arc length ● and arc sector area formulae length arc length r θ ● sector area sector Example Find the area 2 area and circumference of ‘In this circle in terms of terms means your 9 2 Area = of ’ . 2 r = × 9 leave in answer. cm 2 = 81 cm Remember to include the correct units. Circumference = Example Find and the as a 2 r = 2 × × 9 = 18 cm 3 length of number arc to 2 XY in terms decimal of , places. X 6 cm 30° Y r = 6 Arc cm length XY Use the arc length formula. = = 24 6 cm 3.14 cm 7 Measurement G E O M E T R Y Reect Circle to a and and given sector Which ● What gives of the degree Example the problems number ● Find discuss of 2 may decimal most ask accurate accuracy for lengths and areas in terms of , or places. do value? you think is necessary? 4 area of sector PQ. P Give your answer to 3 s.f. 40° Q 8 m θ = 40° r = 8 m Area of sector PQ Use the formula for the area of = a sector. 22.3402… 2 Area of sector Practice 1 Find the terms of PQ = 22.3 area Give s.f.) Remember to include the units. and circumference of each circle. b the Give your answers in . 3 Find (3 2 a 2 m area your c 20 cm and perimeter answers to a 2 of the half 0.4 circle and quarter m circle. d.p. b 7 mm 12 cm mm 7.3 Going around and around 24 7 3 The radius of this circle is 8 K cm. Tip a Find the arc length HI Perimeter b Hence nd the perimeter of sector = arc HI 99° 135° c Find the perimeter of sector length KJ (P 53° H = l + + 2r 2r) 73° d Find the area of sector HK arc r J length I r A 4 In a b this question, Find the Find give length the of all arc perimeter of your answers in terms of π AB. the 120° shaded sector. B 7 c 5 Find This a is the a Find area sector the of of the a shaded sector. circle. perimeter of the sector. 14 b Find the area of cm the m sector. 240° 6 a Find the length of the major arc. 36 b c Find Find the the perimeter area Problem 7 VX and VX = Find UW the the major major cm 45° sector. sector. solving UW the of of = are 12 both diameters of the V circle; cm. perimeter of sector XOW 53° U O W X 8 A frame with The a for vertical and the and radius of this a curved top mirror top sides is 20 an as of arc cm. is in the shown the shape of a rectangle in the diagram. frame are 50 with central Calculate the cm angle long, 97° 97° 20 cm 50 perimeter frame. 30 diagram 24 8 7 Measurement cm not to scale cm G E O M E T R Y 9 Calculate radius 4 the volume of this solid. The end face is a sector of a circle, cm. 4 cm 45° 10 10 A light hardwood cross-section of dowel radius 3 has a cm, cm semi-circular and is 2 m 2m in length. in the Calculate ● In volume of wood dowel. 3 Finding D the Is it this unknown advantageous section you to will values generate generate your more in own of cm circles formulae? your own formulae. ATL Exploration 1 Calculate the 4 circumference of each whole circle in terms of . l 12 cm 3π cm θ has fascinated r people The for Great Pyramid has Use the arc length down a to work general out formula the for fraction nding of the each circle angle of that sector is θ length l and the radius relate Calculate the area of each very the to it. The r base 2 Giza shaded. given closely arc at dimensions that Write centuries. whole circle in terms of . the is square, perimeter which the a is of equal to circumference r of 8 a circle with a mm θ A radius equal pyramid’s to the height. 2 6.4π Use the Write the sector down area A 3 Rearrange 4 Make 5 Rearrange 6 Solve r area the the work radius of the for the for fraction nding of the the circle angle of that the is shaded. sector θ given r you formula formula out formula formula subject the to general and the the a mm found in step 1 to make arc length l the subject. formula. you found in step 2 to make area A the subject. r 7.3 Going around and around 24 9 Example Find the 5 measure of arc θ, 17.59 to the nearest cm degree. θ 14 cm Use the arc length formula. Rearrange and solve to nd ⇒ The = measure Example Find the of θ . 71.988… to the nearest degree is 72° 6 radius of the circle to 3 s.f. r 31.42 mm 120° arc length = 31.42 mm Use the formula for the arc length. Rearrange and solve for r r The radius 25 0 = of 15.0019... the circle is 15.0 mm 7 Measurement (3 s.f.) G E O M E T R Y Practice 1 Find 3 the measure of the central angle of the a sector in each b 9.599 2 mm 2.793 2 5 2 a circle. Find the m m mm angle in the sector. B A 2 b Find the length of the arc AB 11.8 cm 7.5 3 a Find the major measure of the central angle of cm the sector. 2 22.34 b Find the length of the major cm arc. 4 c 4 Find Find the the perimeter radius of of each the major circle. cm sector. Give your answers a to 3 s.f. b 24 cm 2 84 150° m 200° 5 Find the perimeter of the major 6 Find the area of the minor In sector. question nd 16.6 6, rst sector. the angle of mm the 3.14 44 sector. cm mm 3 cm 7.3 Going around and around 2 51 Problem 7 solving Ellie plans to make a paper cone from a sector of a circle with angle 220°. What size circle does she need to start with to make a cone with curved surface area 2 120 cm 8 Find ? Give your answer in terms of the circle's radius, accurate to 1 d.p. the length of chord KM 9 Find the length of chord PQ 2 K 12.57 cm P 3.14 cm Q 3 3 cm cm M 10 The landing radius a 120 Draw b c Find Find d Find a zone m. for The diagram the the a to perimeter area the of javelin central represent of the shortest competition angle the of the this landing landing landing distance is sector the is sector of a circle with 40°. zone. zone. zone. between the two outer corners of the landing zone. Summary ● A chord on ● A a is a line segment with its endpoints ● The arc circle. diameter is a chord that passes through larger is the arc is minor the major arc. The smaller arc the A center of a circle. major ● A secant is a line that intersects a circle at two minor major segment segment arc points. chord ● A tangent one is a line that touches a circle at only minor arc point. B F secant E ● diameter A sector radii. C is The a ‘slice’ center of of a a circle circle is between usually D O, so the means sector the is minor sector BOC. ‘Sector’ sector. A chord B tangent B T radius minor ● A chord divides a circle into two minor segments. The larger The smaller segment is the major sector segment. radius ‘Segment’ ● An arc is segment usually a part of is the means the minor the minor segment. circumference circle. 25 2 segment. 7 Measurement of a major O arc ● two labelled C sector usually G E O M E T R Y ● Two radii triangle. to the and A a line from midpoint right-angled chord of form the the an center chord isosceles of the forms ● Arc ● Sector length circle two triangles. area arc length θ sector ● The formula sector θ = for radius r 2arcsin( the with length angle of a is c chord, = 2r c, sin in area a or ). r c Mixed 1 O θ practice a Find the arc length b Find the perimeter c Find the area of of of sector sector sector DC 3 BD. EB Find the perimeter and a the minor sector b the major sector. area of: B 2 mm 77° C 315° 148° 9 ft 60° 75° D E 2 a Find the length b Find the area of of the the major major arc QR sector. 4 a Find the length of the b Find the perimeter c Find the area of minor the arc. minor sector. R 14 of the major sector. km 105° Q 2 9.817 5 m m 7.3 Going around and around 253 5 a Find the measure of b Find the length of c Find the perimeter d Find the length of the the of central minor the the angle. Toni has lawn sprinkler a rectangular sprays lawn water 8 m up by to 10 5 m. Her m. arc. shaded chord 7 a Draw b By and label a scale diagram of the lawn. sector. using compasses to draw the region MN watered M the best by the sprinkler position for the to scale, determine sprinkler so that it 2 67.02 cm waters c N 8 as Divide the boundary lawn d a Find the measure of b Find the perimeter c Find the length the of central the the angle. shaded watered chord A regular radius cultural dowsing’ as a means of recorded in or even answers throughout as Egypt. far In the side or a back one cloth degree or to the to history as the version, with ‘yes’ which other unlikely the by the the area of the sprinkler. percentage hexagon 5 cm. of the lawn that is constructed your the in a circle answer perimeter to a of suitable and sector lines 25 m long, starting a questions and time has of the center is the is the an event or ‘no’ throwing question of to the The the distance circumference imprint made in the pendulum by the shot in the landing area. a Find the area enclosed by the entire sector. b Find the area enclosed by the sector inside on how it to circle. and one c Hence, nd the area of the landing area. likely going to has a total length of 30 cm, Sector calculate total of the 45 distance travelled if it moved a line 25 m degrees. stop b If the and pendulum it travels an starts arc of facing 10 straight cm, down calculate 10 board cm 2 The high the foul 50 turned diagram put. 2.135 m, The shows the and throwing landing the circle area landing has area is a for the a diameter dividing sector of with 2.135 25 4 line mm angle. 75 shot 7 Measurement of the held sways is circle circle. from pharaohs is written indication in the has been the pendulum pendulum of measured 34.92° If the degree happen. a is sprinkler. Calculate Give throwing above calculate nding soil used garden isosceles solving 34.92° thrown expression the been the two context and gold and km from water, inside sectors accuracy. angle ‘Pendulum possible. km 10 1 lies as UV of Personal by the watered hexagon. in that lawn sector. of Review the two Hence, Calculate not 8 19.20 circle into Problem of of cm triangles. 6 much m cm line wide the G E O M E T R Y 3 ‘Medicine wheels’ Americans Medicine diameter for a Wheel of the a 28 days of Calculate each is about approximately were variety a 24 equal the the used of by circle of meters. The stones It sections, lunar native rituals. is c Big with divided likely to Horn found a events into 28 spots represent 20 calendar. approximate Dierent to (winter related meters distance central angle of d sector. spots The measures b Calculate the area of each and How you have of 80 rising rising of Calculate along the circle the star points been astronomical of the their stars). star Two Sirius between approximate Aldebaran happens central Calculate angle the shortest them. discuss explored the statement of inquiry? Give specic examples. Statement of Inquiry: Generalizing and analysis relationships of activities between for ritual measurements and enables the are circle. whose degrees. have specic sector. distance Reect the apart. two the to solstice, to apart rising between along correspond construction play. 7.3 Going around and around 25 5 Which triangle is just right 7.4 for you? Global context: Objectives ● Solving problems trigonometric ● Knowing the Scientic Inquiry in right-angled triangles ● using F ratios properties of trigonometric technical innovation questions How do you nd immeasurable ● ratios and What are the measurements of objects? relationships in the special triangles? ● Solving problems SPIHSNOITA LER elevation and that angles include of angles of depression ● C How do angles nd ● D relationships in right-angled real-life How does ratios Critical-thinking Propose and evaluate a sides help understanding help and you measurements? you mathematical ATL between triangles create the and trigonometric understand models? skills variety of solutions 7.4 14.2 Statement of Generalizing Inquiry: relationships measurements models 25 6 and can lead methods. to between better G E O M E T R Y Y ou ● should use the in know Pythagorean theorem side already a to nd the 1 missing how Find in T R I G O N O M E T R Y to: the missing accurate right-angled A N D to 3 s.f. side All in each triangle, measurements are cm. triangle a b 5 x 17 x c 10 12 ● relate angles right-angled the and sides triangle trigonometric (sine, cosine and of a 2 Find using x sin A, solve the simple tan A and tan B A ratios tangent) a C ● cos B, problems trigonometric using 3 ratios Find B the value of x in a each triangle. b x 10 m 10 m 9 m 60° x Right-angled F triangles trigonometric The ● How ● What right angle do is are the at right angles to their foundations. geometry and to you our nd the most This ratios measurements relationships earth, common and and the in the angle homes fundamental in of special our we angle immeasurable is triangles? world live at objects? in the – are after built heart of all, at we right the stand angles study of trigonometry. 7.4 Which triangle is just right for you? 2 57 Activity ATL 1 Make very the a list tall of Write 3 Discuss these method rst. If down you were the Draw and a methods standing 6 surveyors survey distances and would angles land have already but distances? did In Practice an use to where nd you the are height in of a relation to ratios to ratios do of the front job in of a order each starting they building, to relating method. with the best these and what calculate its height? measurements. prepare always surveyors line their sine, that a them boundaries land use are maps measuring of use vision to and instruments, cosine, and measure an object. together tangent, far to with determine angles? about so, with in take their using order. equation tools and know to rank of angles. surveyors learned you In between heights order trigonometric of and ground need property and kind(s) trigonometric triangle, Use could state disadvantages others the you write distances immeasurable 1 and and ranking accordingly. what the on determine plots Research How You you method, with your would diagram immeasurable 5 methods each advantages Explain measurements Land For building.’ 2 4 dierent building. the trigonometric they you can will help need to you ratios in a determine review how to right-angled immeasurable nd the calculator. 1 your calculator to evaluate these, either exact or to three signicant gures. Tip a sin e tan 47° b cos 32° c tan 17° d sin f cos 60° g tan 45.8° h sin 2° Make 89° sure your calculator degree i cos 0° j tan Find the angle in each expression. sin A = 0.467 b cos B cos α = 0.898 e sin g cos φ = 0.123 h tan Reect Take of a and closer Practice ● What ● Can c tan C = 1 look at the β = A angles. 0.5 = f tan θ = 3 27.3 1 values of the trigonometric ratios 1. do you 25 8 discuss you notice explain the about is in (not the reason range for 7 Measurement your of values for observation? each? in the questions mode) you degrees = 2 d radian when 2 a mode 30° in 2 that 0.789° to are using measure G E O M E T R Y Some people use trigonometric with acute SOH — CAH — TOA — the ratios memory in 2 1 knowledge your each triangle. aid SOH-CAH-TOA right-angled triangle. for Given remembering a T R I G O N O M E T R Y the right-angled triangle α: angle Practice Use a A N D of Round the your trigonometric answers to the ratios to nearest nd b a the side hundredth c 4 cm marked where x in necessary . 11 cm x 60° 37° 11 cm x x 41° d e f 45° 47° 3 cm 50° x 7 cm x x 10 cm 2 Find All the angle lengths are θ in in each triangle. Round your answers to the nearest tenth. meters. a b 13 θ 4 θ 3 3 c d 11 θ θ 10 11.9 4.4 3 Find a all missing sides B and angles A in these right-angled b triangles. c C C B 62° 22.6 cm 53° C A 3 cm 40° B 5 cm A d B e A B 28° 14 cm 6 cm 24° A C C 7.4 Which triangle is just right for you? 25 9 Objective: i. use C. appropriate terminology) In Communicating this in mathematical both Exploration, sketches to be able you to a method building to nd out Method 1 you to 1: Sketch 2 the the tall use appropriate that symbols and your and answers accurate are notation in your justied. discussed height. your school Y ou is in the are Activity now without going actually is to to use the explore measuring shadow two its of methods height. and its that shadow is in your represented by notebook, this and situation. draw Label the the sides triangle. what these your the sketch that represents height 2: 1 small a can see to you calculate would the height need of to the make in building. order If you to use can, measurements. nd Put measurements ratios Use Method 2 to others have its triangle trigonometric 3 may building Determine make need (notation, explanations Shadow right-angled of will language written 1 measure how and convince Exploration One oral to of determine the the which building. situation. trigonometric Write (Solve down it if the you ratio will help trigonometric have actual you equation measurements.) Mirror the Measure building mirror top your to of on the the distance the ground building to the in and the stand far middle mirror, your of enough the height away that you mirror. and the distance of the mirror. 3 Sketch the situation 4 Justify how 5 Explain how you could calculate the height of the building a using the two and indicate triangles in the measurements your diagram are in your diagram. related. trigonometric ratios and b without using trigonometric ratios. Reect and ● method Which method? a Using of the the as Identify nd you your the 2 think Pythagorean a is more accurate, the shadow or the of theorem, this nd triangle. the Leave length your radical. what type missing of 1 triangle this is, and thus angles. 1 Continued 2 6 0 mirror answer. 2 hypotenuse answer b do Justify Exploration 1 discuss 7 Measurement on next page G E O M E T R Y c Hence, use triangle to your nd knowledge the of following trigonometric values (leaving ratios your in a right-angled answers as T R I G O N O M E T R Y The very 45° cos ° 45° tan ° consider the 45° a Using nd b your memorize, as equilateral angle knowledge that bisector triangle shown of equilateral of the the sum Using of the the in a dotted base. line Using triangle, Pythagorean dotted Hence, ratios use in a following sin your is the your nd 4 right-angled values of nd the the β β 2 length help cos results your step 2, which was other? What triangles solve Practice By using answers to nd answers the in surd tan 60° tan c 60° ° and 2 d by comparing the surd form with the calculator was the greatest about are 1 30° the known longest angle? shortest as side of Where side ‘special the were and right-angled these the triangles’. in triangle relation smallest to and each angle? Recognizing these ratios can problems. 3 the in the in form): 30° ° your α 2 trigonometric ° 60° from you your cos values These of ° which angles. β angle triangle (leave 30° Check In these perpendicular knowledge theorem, knowledge ° 3 nd line. ° sin used triangles, α d methods here: 2 c are ° α angle Assume this are to to 2 of useful the Now results exploration radicals): sin A N D special radical triangles, form nd where 1 the unknown measurements. Leave your appropriate. 2 3 e You can check 60° b 12 cm youranswers c 5 m 4 m Pythagoras’ using theorem. 45° 30° a d f 4 5 h g 6 cm x 6 cm 3 cm 7.4 Which triangle is just right for you? 2 61 Real-life C ● How do relationships triangles Example Y ou are applications help you between nd real-life sides and angles in right-angled measurements? 1 standing the ground. the building 9 Using is m a 50°. away from sur veyor, Find the a you building, read height of the the and your angle of building eyes are elevation to the 160 of cm the nearest from top of meter. x Draw 50° 9 a 50° = ⇒ x = 9 × tan 50° = relation side 10.726 + 10.726 = to adjacent opposite 1.6 and label the side, An angle is of about 12 m below depression An the the angle between above horizon is and the an angle of depression object of elevation horizon is the angle an object and horizon. angle Reect ● Why ● The we angles units. ● and do are and to the of angles of cosine and right-angled units of the tangent triangles trigonometric elevation as are measured ratios? 2 The and m when it To a the angle of is 2 6 2 Tower ground. standing elevation on ying the the originally person Gina high Leaning was limitations 3 answer. of depression equal? above angle specic your of elevation solving famous 55.86 in Justify ratios? 4 Problem 1 elevation trigonometric angle Practice of 3 sine, sides are the depression discuss refer What Why your kite you are information. use are given looking for the the tangent. the a is built 130 of kite that above m away top of of ‘leans’ a ground 7 Measurement the at from a your makes the Pisa (standing the accuracy of Determine at an angle height right the of that 4°, top to a is of its angles base building of the and above m top the is ground ground). building, 58 its determine high. Explain the answer. 50° angle when she with has the let ground. out 150 m Determine of string. height round horizon. the the you hence tall. angle between given 12.326 and building angle, and Add The the m In tan sketch how to to the the answer nearest meter. G E O M E T R Y 4 A vertical altitude 5 A ladder angle the 6 A of that 60° ship is on of depth Reect ● For For is get the of the long is a of far up of away shadow which against Determine it the is 1.3 m long. Determine T R I G O N O M E T R Y the elevation). leaning ground. how is on the water, at side far of the a building ladder’s making base is an from building. and underwater, the how its an radar angle detects of a submarine depression of 23°. at a Find submarine. discuss 3, question to 3, to the 4 2, as 4, the specic as happens and as describe sun’s understand, between what building, question stick represented Example casts angle surface the important m m closer relationship Find the long (its the and Practice normally 6 and shadow It is with 238 of 1m sun Practice you ● the building, distance the stick of A N D at sides either a what altitude this point, of a to you the get angle farther happens elevation the the as building? length of the changes. that a trigonometric right-angled fraction to of from or triangle. ratio That is ratio a is decimal. 2 length of the side labelled x to 3 s.f. x 40° 500 25° Separate the unknown triangle side in the into two upper right-angled triangle triangles. and use to s.f., the trig Label ratios the to nd a it. Since thenal the nal answer answer must be is required carried out 3 to at all calculations least one more before s.f. 40° 500 tan 40° = ⇒ a = 500 × tan 40° = 419.5 500 25° Label the unknown side in the lower b triangle tan x = 25° a + = ⇒ b = 500 × tan 25° = use trig ratios to nd it. 233.2 b Add = and 419.5 + 233.2 = 652.7 = 653 (3 the two lengths that make up the unknown side, s.f.) and round to the required degree of accuracy. 7.4 Which triangle is just right for you? 2 63 Example In the diagram, depression of 3 AC from depression C = 52 to from B C m. is The 28°, to D and D is angle and 42°. the of C angle Find 28° the 42° distance between B 52 m 42° 28° A In ΔABC, In ΔABD, ⇒ BD = tan 28° tan 42° 97.80 Practice 1 Find = the D ⇒ = Use B the trig ratios to nd the required sides. ⇒ 57.75 = 40.0 m (3 s.f.) 5 missing length x in each diagram. 61° 35° x 39° cm 60° 9 38 2 Find the side length x in each cm x cm triangle. a In b 2, you will need 101° 23 71° x 12 mm x mm to mm decide draw mm order the 44° Find the angle θ 4 Find the distance m in the diagram. 30° 12.4 θ 58° 20.6 m 5 Find the of B A, heights and from the ground C 6 Find the side length x diagram. B 10.2 m 900 m 75° A 20° C 11.4 479 m 8.5 72° 3.2 m 58° m 2 6 4 dotted 7 Measurement m x m in this to solve problem. to line 50° in 3 a where G E O M E T R Y Problem 7 A single an speed for private speed an determine T R I G O N O M E T R Y solving engine average A N D a of hour how plane 110 and far a ies km/h. half the It on plane due North for then tur ns and a bearing has of travelled, an 130°. and hour ies b at and the 18 minutes same At the its bearing end of at average this from time, its initial position. 8 Two The ships rst travels are 9 A leave one on from a and 60°. of travels from Reect top the How does ● How do you More How and Using What 3 Summarize ● ● What a ● the think on does was bigger What Why 0° your we 60° at km/h. travels 23 on km/h Determine a straight and the how far line second the course. one two ships noon. hill that angle of post, lookout is 100 m above depression the angle of of sea a level. boat out depression From at of sea the the is 30°, boat is post. 5 help solve the determine problems immeasurable when the distances? triangle understanding the isn’t a ratios trigonometric mathematical and ratios help you create models? of nd values cannot greatest could your no of in sines, cosines and tangents of several a each of the three ratios? table. 6 right-angled the the 90° discuss angle, there trigonometric ndings angles does is the of one 3 range and of of a the each triangle? Considering cosines of 28 lookout calculator, 2 Reect top the at 12:00 post, of between is at and bearing understand your angles a 115° discuss Exploration 1 10:00 trigonometry right-angled ● on height and ● D is lookout the Find of another post the at on bearing one lookout base port triangles, be greater value you you have calculator maximum say give found found when value reasons than for for an a tangent even you the why the sines and 1. greater enter tan tangent ratio? By choosing value? 90°? Why is this? ratio? 7.4 Which triangle is just right for you? 2 6 5 So to far, you should right-angled ● The the lengths angle. ● the side of the The sine the ratio or one to is greater of the Draw legs a is to make the the zero), be the in a the are following generalizations related is shortest side length the is of proportional side will be triangle one of hypotenuse always is larger will opposite is to therefore 90°, the the be smallest longest the legs always than the divided the by longest numerator; the side, hence 1. ratio of the leg legs that make other. The tangent greater are longest right-angled the the The triangle The hypotenuse. Since than the than 1, or up equal opposite the can to right the angle angle therefore are be to the either less equal, than 1 (but 1. short triangle (very close where to one length of 0) the and B the leg 4 right-angled very angles. fraction angle than right-angled and ratios angle. Exploration 1 to less an larger than has of always a angle hypotenuse. the tangent of angle, cosine denominator adjacent able opposite largest the The sides triangle is been their the and of the of largest Since length ● of measures opposite have triangles: hypotenuse is 5 cm. Label it like a this: A 2 Measure 3 Using sin A, 4 lengths the and denition cos A, Explain a sin B what b of and b sine and cosine, nd cos B happens to sin A as side a gets You might look at the eect on sin A and cos A as angle A gets closer to In Exploration mathematical the 5 eect you will concept 5 1 (5, the points 0) sin B see you Exploration Plot on and how have and the cos B as tangent angle ratio B is gets closer related to to tan A 90°. angle closer the line segment (10, joining Measure the angle between to zero. 4) on these graph two paper. Calculate the gradient the line gradient nd the tangent of the and the x-axis and use your calculator straight between line (x angle. (x , 2 3 Write and 4 Plot down the the points joining segment and the line segment two parallel Justify the to the the 2) and 4), the Then, line of (3, Find values, tangent the and x-axis. the you notice between the gradient of y = and the and nd −2. the nd tangent the Write of the tangent down relationship angle gradient the formed by angle of the what line the angle you between the of line line between the notice the line between segment the between gradient and of a the line x-axis. relationships you noticed in steps 3 and 4 Continued 2 6 6 the angle. them. the tangent and relationship of (0, segment line 5 the tangent 7 Measurement of points. , 1 to tan B gets another a 2 A studied. The of and zero. as Generalize to eects smaller. on Generalize want the on next page y ) 2 is m y ) 1 and G E O M E T R Y 6 Consider the y-axis. and the What x-axis Plot is of as the two formed of of the and line Find the in the when 4) be line why a 1. Write move tangent point you and to move the down the of closer when the the this point nd what point (10, angle y-axis. point is on happens 4) closer formed by the Determine on the to the of the line the y-axis? y-axis? y Note segment negative that you nd (0, 4) the should T R I G O N O M E T R Y to to between tangent the you the angle (0, step as segment Explain angle of the segment between x-axis. tangent move 0) the segment segment change you (5, of points. the the line points gradient and on line tangent the angle line the the the the the of Reect gradient 7 again gradient A N D the the angle the line positive value. is between and the x-axis. obtuse So θ (> 90°). θ x (5, 0) The idea of trigonometric right-angled triangle will ratios be for angles explored that further cannot in the be MYP represented 4/5 in Extended a book. Summary ● The trigonometric triangle help couldn’t you easily ratios make make in a right-angled measurements ● that Some results worth knowing: you otherwise. 2 √3 ● 60° √2 The largest angle in a right-angled triangle 30° 1 is the right angle. The two other angles 2 30° √3 are 1 45° 60° always acute angles. 1 1 ● The longest side in a right-angled the hypotenuse (opposite the other called the triangle right angle) is and sin ● In a cos right-angled are value ● The and sides, always of tan triangle, between can following legs, be any results 0 are the and value hold values 1. of sin for than sin, cos the 30° = sin 60° = 45° = cos30° cos = 60° = cos tan 45° = tan 1 30° = tan 60° = the tangent tan: 0° = 0 cos 0° = 0 tan 0° = The 90° = 1 cos 90° = 0 tan 90° gradient of a line is equal to of 0 the sin sin 0. ● sin = and However, greater true 45° shorter. = angle that the line makes with the positive undened x-axis. ● Angles of depression angle of and elevation: depression angle of elevation 7.4 Which triangle is just right for you? 2 67 Mixed 1 A kite the practice string angle from 27 48 m between degrees increase the is in the long. the to 54 As kite the and the degrees. vertical height wind blew, ground Determine of the kite 4 In a house that is being renovated, two corridors meet at right angles, as shown in the diagram. went Workmen attempting to take a ladder around the the corner get the ladder stuck when it is at an angle of above 45° to each wall. ground. 48 a Determine the b Determine the stuck it length length of of the a ladder. 2nd ladder that got 48 54° 27° wall when of the was 1 m at an angle of 60° with the corridor. 45° 2 Find length x in each diagram. 2 m a 1 6 7 m 4 0 25° 3 8 1 m x Problem 5 A 5 m solving ladder is resting against a vertical wall. b The base of the ladder is 2 m from the wall. 57° Keeping mc that 4.8 1 it m which 2 2 is its now base rests away. the xed, the against the Determine ladder has ladder rotated opposite the been is angle wall so which through rotated. x 3 ABCD and is PB a = square, 12 where AP = 5 cm, QC = 7 cm cm. 5 m Calculate: a the size of b the length the of angle marked x AB x 2 c the length of DQ d the length of PD 6 e the size of coast guard two depression ∠BQD C D Q 2 6 8 A observes P 7 Measurement of Determine m attendant boats 45 how in m atop line degrees far 1 and apart a with the cli him 69 120 at m degrees. boats high angles are. of G E O M E T R Y Review in A N D T R I G O N O M E T R Y context Scientic and technical innovation 1 In 1852, an Indian mathematician, Radhanath Legend Sikdar, used measurements and has calculated to calculate the height of Peak XV in (later to be named Mount required the use of a device that from the ground to the top of an measuring from two distance come the between up angle dierent with a to spots, these the and drawing like top of Peak knowing spots, value Sikdar Sikdar the that would believe him. he thought Supposedly, added 2 feet to make it more believable! books record his calculated height object. to By the perfect measured History angles so Everest). he This that was the nobody Himalayas it trigonometry be 29 002 feet. XV the may 2 have You to following: are the the pilot aireld altitude is of after 3050 m a a light aircraft, parachuting and you are returning trip. Your heading towards P the landing What that angle you strip of touch which is depression down on currently should the 14 you landing km use strip away. so at h closest 45° O The x angle (from point the was height How you of Generalizing and 17 409.7 to the measured closer feet top to (point of B the be 32°. A), the peak From angle a of 45° and Statement was feet Reect have 32° A elevation B) 17 409.7 elevation Find of point point? Sikdar calculated for Peak XV. discuss explored the statement of inquiry? Give specic examples. Inquiry: relationships between measurements can lead to better models methods. 7.4 Which triangle is just right for you? 2 6 9 the 8 Patterns Sets of numbers or objects that follow a specic order or rule Patterns Patterns play in an understanding follow from language other is Subject, Many a elmayı for languages, the of is use apple the apple’. structure The known in Steve an pattern titled and musician Search online performance clap 1 clap 2 27 0 the ate’, as and in that and in using a order. In ‘Iskender word the vary structure built order as English would of often structure. in and be patterns ‘Iskender in language linguistics. music American in over starting for but study SVO sentence translate Music repeated SOV learning sentences English, are Object, the structure ‘Clapping rhythm one is In the sentence Patterns Reich an the patterns sentences and in Simple language. would the translation those example, yedi’ ‘Iskender and simple Verb role language. to languages Turkish, ate – Romance common: important of patterns language for half if music. two 150 ‘Steve see his composer beat Reich you One people’, times, a who but his and with later follow famous consists 8 music’ any of variation every clapping can of experiments with works a is single created by bars. to listen patterns. to a live Patterns in physics Johannes Kepler discovered explain planets third the the tells it laws motion around time orbit physical the law (1571–1630) the us takes sun, of sun. that a and that the if His T is planet r is to the 3 radius What of its does orbit, it then mean to T ∝ r 2 have 3 an exponent of ? By 2 looking When bank you interest What the invest usually savings; in with can fractional pattern you money banks is at a interest bank, on compound year be can a the at the help fair needed through generated account Understanding would sensible exponents, we exponents denition. the your the annually. bank each give when nance awards many patterns working a Patterns for to the by end pattern you value to for withdraw the of at each the work an amount year? end out of what investment money in if partway year. 2 71 What comes next? 8.1 Global context: Scientic and technological innovation Objectives ● Understanding Inquiry and using recursive and explicit questions ● What ● How is a sequence? F formulae for ● Recognizing ● Finding a MROF quadratic sequences linear general and quadratic formula for a sequences linear a ● or sequence ● Recognizing ● Solving problems real-life contexts can you describe the terms of sequence? What is a general formula for a sequence? patterns in real-life contexts ● What ● How can ● How do types of sequence are there? C involving sequences in a ● you you identify nd a sequences? general formula for sequence? Can you always predict the next terms D of ATL a sequence? Critical-thinking Identify trends and forecast possibilities 8.1 Statement of Inquiry: Using dierent improve forms products, to generalize processes and and justify patterns can help solutions. 12.1 12.2 E8.1 272 A LG E B R A Y ou ● should identify the already next term know in how a 1 sequence to: Write each a 2, b c ● substitute into formulae 2 4, 4, 0, 2, 8, 14, 6, the 6n b 6, 9, Find a down the next two terms in sequence. + 2n … 19, 12, … … value 3, + of : when 7, n when = n 4 = 10 2 c n 1, when n = 2 2 d ● solve simple linear and quadratic 3 equations 4n 2n Solve a 3n b 5n for + + 11, when n = 1 n 7 = 19 2 = 14 2 c ● write a simple general formula number for 4 patterns 5n Find b 4, Introduction ● What ● How ● What is a can is a to 1 = 181 formula for the nth term of sequence. 8, 12, c F a each a + 12, 24, 3, 16, 36, 6, 20, 48, 9, … … 12, 15, … sequences sequence? you describe general the formula terms for a of a sequence? sequence? ATL Exploration 1 Describe list of numbers. a 1, 3, 5, 7, 9 b d 1, 2, 1, 2, 1 e Predict with 2 each 1 Here 3, 1, the next three 1, 6, 4, Compare 9, 12, numbers 16, 24, in your descriptions 25 48, each c 96 f list. Compare 7, 0, with 10, 1, your 13, 8, 6, others. 16, 5 results others. are 4, Tip two 1, 5, 19 dierent 1, 6, 1, 7, ways 1, of continuing the list 3, 1, 4, 1, 5, … Search online for ‘3 5 5 1, 4, 1, 5, 9, 2, 6, 5, 3, 4 1 9 you need the pattern in 6 3 help 5 identifying Explain 2 8 if 3, 1 each one. the pattern. 8.1 What comes next? 273 5’ Reect Here is 0, Is a 1, Try way 8, there a ● Could ● If In 5, searching Does a 6, of discuss 1 continuing 5, 5, 6, 7, 6, the list from 1f in Exploration 1: 7 pattern? ● A and this one online list of have digit was is an the numbers numbers you sequence for count identied missing, ordered the as of a like this: 01865 556 767. pattern? sequence would list grouped you be numbers. without able to Each an nd internet out number search? what in the it list was? is called term some sequences sequences discuss 1, in the Exploration however, Describing terms terms is in 1 not a follow were a a pattern, generated mathematical specic by a rule pattern. or The order. list in All the Reect and pattern. sequence The You can use to u represent the rst term of the sequence, u 1 thesecond Forthe to subscript sometimes represent and sequence term 1, so 3, on. 5, 7, The 9, subscripts 1, 2, 3, match the term number. the index term. ... 2nd term 3rd term 4th term 5th As = 1 u 1 = 3 u 2 = 5 u 3 = 7 u 4 could also use u for the rst term, so the the is word also = 9 to mean ‘exponent’, you 5 need You of term used u called 2 term, ‘index’ 1st is to work out that: 0 its 1st term u = 2nd 1 u 0 term = 3rd 3 u 1 Sequences starting term = 4th 5 u 2 from u are often term = 5th 7 u 3 the sequence, the used in computer = do not match the programs. term When u Tip number. Be Reect and discuss context. 9 0 subscripts the 2 careful you talk rst term’ mean ● Why is the notation u , u 1 ● terms a, b, What does c, d, u e, , u 2 , 3 u , 4 u , … more useful than labelling the 5 …? mean? n Describing An its a sequence explicit formula using uses the value. 2 74 an 8 Patterns explicit term’s formula position (position-to-term number, from 4 0 starts term meaning n, to rule) calculate u 0 when about – or do u ? 1 ‘the you A LG E B R A The formula u = 2n 1 for n ≥ 1 n tells us that the value of the nth term (u ) is given by 2n 1 for any value of n n greater an than or equal to 1. When you are working with sequences, n is always integer. Using the above u = 2 = 1 formula, × 1 letting n = 1 gives the following: 1 1 Similarly, letting = 2 = 3 u × n = 2 2 gives: 1 2 and so on. Example 1 2 A sequence is given by the explicit formula u = 3n 2 for n ≥ 1. n a Find: i the rst, ii the term b Determine a i Since n second of the and sequence whether ≥ 1, tenth the or not terms terms with 524 is of the value a required 673. term are sequence u of , the u 1 sequence. and u 2 10 2 u = 3 × 1 = 3 × 2 2 = 1 2 = 10 2 = Substitute n = 1 for the 1st term. 1 2 u Substitute n = 2 for the 2nd term. 2 2 u = 3 × 10 298 10 Substitute n = 10 for the 10th term. 2 ii 3n 2 = 673 = 675 = 225 n = ±15 ≠ −15, Solve the explicit formula for the specic value of 673. 2 3n 2 n As n ≥ 1, n so n = 15. 2 When n = 15, u = 3 × 15 2 = 3 × 225 2 = 673 ✓ Check your solution. n b If 524 is a term in the sequence, then 2 2 3n = 524 = 526 = 175.333… 2 3n 2 n n is not an integer, so 524 is not a term in the sequence. 8.1 What comes next? 2 75 Practice 1 Find the 1 rst ve terms of each sequence. 2 a u = 4n 1 for n ≥ 1 b u n = 6n + 2 for n ≥ 1 n 1 2 c u = 10 n n for n ≥ 1 d u n = 2 2 4n 5 for n ≥ 1 n 4 e u = (n + 4)(n 3) for n ≥ 1 f u n 25 155 for n ≥ 0 u = 1051 1307 4 g = n 3 n 2 n + n n + 45 for n ≥ 1 n 24 2 Find the 12 tenth 12 24 term of the sequence given by u = 5n 3 1 for for n ≥ n 1. 1. n 3 Determine if 54 is a term in the sequence u = 4n ≥ n 4 Determine which term of the sequence u = 3n 5 has value 61. n 10 5 Find the fteenth term of the sequence given by = u 10 for n ≥ 1. n n 6 Find u = the 2n value + 12 of for the n ≥ fourth term of the sequence given by 0. n 2 7 a Find the term of the sequence u = 2n + 4 that has value 246. n b Show that 396 is a term in this sequence. 2 n 8 Find the eleventh term of the sequence given by u = 100 for n ≥ 0. n 5 Tip Problem solving The 9 Identify which explicit formula, a to f, corresponds to each sequence, i to vi command term identify requires a = u 4n + 1 for n ≥ 0 i 3, 6, 9, 12, 15, b u state = 2n + 3 for n ≥ 1 ii 1, 3, 5, 7, 9, … you n c u = 5n = 3n = 3n = 2n 4 for n ≥ 1 iii 2, 1, 4, you to … n 7, 10, … briey have your how made decisions. n d u for n ≥ 1 2 for n ≥ 1 for n ≥ iv 1, 5, 9, 13, 17, … 0 v 5, 7, 9, 11, 13, … 0 vi 1, 6, 11, n e u n f u + 16, 21, … n Describing A a sequence recursive When With you this formula know recursive using gives one formula the term, formula a relationship you you (term-to-term can are work given between out the the value rule) consecutive terms. next. of u : 1 Tip u = n + u 1 + 2, u n = 1 for n ≥ 1 1 u u = 1 is the nth term of n 1 a sequence, so u n Substituting n = 1 gives the 2nd is u = 1 + u 1 u + 2 (n 1 = 1 + 2 = + 1 term: the + u 3 next 1)th term or term. is the term before the nth term. n − 1 2 Substituting n u = = 2 + u u 1 = 2 gives + the 3rd 2 2 3 + 2 = 5 3 and so on. 27 6 8 Patterns term: A LG E B R A Example A 2 sequence has term-to-term rule u = n Find u = the 2nd and 3rd terms of the + u 1 + 8 for n ≥ 1, and u n = 12. 1 sequence. 12 The rst term is given with the formula. 1 u = u 2 + The 8 2nd = 12 × = 6 + = 14 + is found when n = 1. 8 8 Use u term 1 = u 3 + the value you just got for u 2 8 2 to = = 7 = 15 You 14 × + can graphs + nd the 3rd term. 8 8 use for a the GDC to plot formulae in explicit and Examples 1 recursive and 1.1 formulae. Here are the 2. 1.1 Tip u u n n 16 80 Some GDCs use (4,15.5) 70 15 u (3,15) = 3 u n 2 u 60 and n n rather 1 2 n than u 14 and n 50 u + 1 . n 1 (2,14) u u n 40 13 n + Inthis 8 1 example, the 2 30 12 20 u (1,12) = u n + n 8. 1 11 10 0 10 n 0 1 2 Practice 1 Find a b the u + 1 n + 1 u 4 n 0 5 1 2 3 4 5 6 7 8 9 10 2 rst = n 3 ve 4u 1, terms of u n = 2u each sequence. = 1 for n ≥ 1 = 2 for n ≥ 1 Tip 1 + 1, u n Look when c u = n + u 1 for patterns 1 + 7, u n = −4 for n ≥ you work 1 1 with sequences. 1 d = u n + u 1 + 1, u n = 3 for n ≥ Do 1 the terms of the 1 2 sequence e u = n f + u n (1 u n = + 2u 1 4u 1 ), u n (1 u n = 0.8 for n ≥ ), u increase, = 0.8 for n ≥ to 1 1 n seem 1 or decrease, bounce around 1 chaotically? g u n = u n + − 1 3, u = 4 for n ≥ 2 1 8.1 What comes next? 277 2 A sequence is given by u = 3 u n + 1 Find the rst four terms of and u n the = −3. 0 sequence. u Tip 1 n 3 A sequence is given by u = , u n + 1 = 2 for n ≥ 1. It can be useful 1 u n a Find the rst b Describe c Predict any the Problem 4 A six terms patterns next few of the you of the is given by u = 2u n + 1 5 A the term sequence the of is the given value The C fewterms to explore an unfamiliar sequence. sequence. sequence by of the u = What ● How can ● How do types largest of you you that has 3u 2, identify a 2 for n ≥ 1. value u = 2 ≥ 1. 257. for n 1 term of = 1 in the sequence that is less than 10 000. sequences sequence nd u n structure ● 1, n n + 1 Find a solving sequence Find list sequence. notice. terms to are there? sequences? general formula for a sequence? ATL Exploration 1 For each a 3n = + 2 sequence, write 7 c n b a = 5n = 4n the rst ve terms. 2 n = 3 2n d n 2 down + 5 n Copy and complete the diagram for the sequence given by a = 3n + 7, n lling in missing Sequence terms in 13 10 the sequence 16 and the rst dierence row. 19 The is F irst difference 3 rst the 3 between b 3 Make Look at a similar your a Describe b Compare formula. between c What Sequences by a like constant 278 do diagram anything rst the other the the you sequences in step 1 terms. for anything you explicit explicit ones number, notice. dierence Describe the for diagrams. the dierence dierence in are formula each and formulae sequence notice. of the value these Exploration 2, sequences. 8 Patterns of a the sequences called linear with Suggest where the its explicit relationship rst dierence. have terms in common? increase or decrease consecutive A LG E B R A For a linear constant sequence, and the the explicit dierence formula is between of the consecutive form u = a + terms is bn n Reect ● If you Plot discuss plotted graph ● and would the the terms you graph 3 of a sequence 7 to from Exploration 2, what type of get? of a = 3n + check your answer. Plot coordinate pairs n as (n, a ). n ATL Exploration 3 2 1 a Copy and complete this diagram for the sequence given by e = n + n + 5, n lling in missing Sequence terms 11 7 in the sequence 17 and the dierence rows. 25 The F irst difference 4 second dierence is dierence between consecutive Second b difference Make 2 a similar + 5n the 6 rst dierences. diagram for each of these sequences: 2 = f n + 6 n 2 g = 4 + 5n + n n h = n(n + 4) + 1 n 2 Look a Describe For a the and second dierences dierences between in these your diagrams. sequences and the sequences 2. anything you notice that the about the rst and second dierences of sequence. Describe in rst Exploration each c the Describe in b at anything explicit formulae for these sequences have common. quadratic sequence, the second dierence is constant and the 2 explicit formula is of the form u = a + bn + cn n Reect ● The and discuss sequences highest power in 4 Exploration of n in of the a 3 are quadratic quadratic sequences. What is the sequence? 2 ● Plot the graph sequence e = n + n + 5. What type of graph do n quadratic ● Other sequences than sequence linear can you produce? and quadratic sequences, what other types of describe? 8.1 What comes next? 279 Practice 1 By is 2 3 constructing a quadratic Complete in the a these F irst c 11 4, c 91, 3 e 5, A 11, 17, 32, 64, 71, ... any missing terms in the sequence and 27 3 23, 29, 5 each sequence … a the is b … for Usually 6 … 51, formula term. a in 18 3 4 25, 75, Example Find 52, 8 whether 18, general each 36, 15 difference 84, 23, 4 difference 11, 13, 11 Determine a 6, solving difference Second sequence 2 difference Sequence F irst the 3 difference Second that lling Sequence b 3 by 6 3 Problem show rows. difference Second diagram, diagrams dierence Sequence F irst a sequence. sequence general linear, 104, 97, d 2, 4, f 4, 12, is a rule formula is quadratic 7, 90, 11, 36, that an 83, 16, 108, can 76, neither. … … 324, be explicit or … used to generate formula. 3 general formula for u , the nth term of the sequence 11, 17, 23, 29, … n Sequence 17 11 23 29 Find F irst The 6 difference rst dierence 6 is 6, the rst dierences. 6 so compare to the sequence u = 6n The rst dierence is constant n sothis n u 1 2 3 4 11 17 23 29 6 12 18 24 is a linear sequence. n + 6n 5 Look for a pattern connecting 5 to 6n gives u n The general formula is u = 6n n 2 8 0 8 Patterns + 5. u and n Adding 6n A LG E B R A Notice It that doesn’t need the more formula mean information Practice 1 general necessarily you that about the the nd describes pattern will sequence, for the terms continue. example, you To if it were know is given. that, you linear. 4 Find a general a = 8, formula to describe the terms in each sequence. Tip ATL a a 1 = 16, a 2 = 24, a 3 = 32 4 You b b = 14, b 1 c = = −14, e e c = 49, d 11, −28, 38, = 17, f = 29, g = 7 i 15, i 1 2 set = of a = 9, a = c 17, b = 13.5, d = 7, d string = of g = = 18.5 6 7.8, h = 12.4 4 −21, i is = −39 part of a describing 13, a b = = 11, linear the sequence. terms of each sequence. 15 b = d c = = 8 14 14.5, c = 15 12 23, d 9 = 31 11 solving decorative then d = 11 connect Let f 8 14, cable connect b h = why to few 4 a 15, rst the 16 4 = Explain and 7, below 7 Problem a = 10 5 A g 14, = out −56 65 13 c is working terms. = 18, formula = by 4 12 9 d = 7 11 c f i 11, correct 3 6 = = e 3 general b = 3 terms your 4 3.2, −3, a 5 3 = Find a d 3 h check formula 1 , 2 Each b 47, 2 = c 3 −1.4, can general 4 = 2 = 27, 3 1 i e 17.5, 3 h −42, 3 = 1 h 23 2 , 8 = 4 = 2 g = 3 = 1 g c d 2 1 b 3 = e 1 f = 2 = 20, 4 2 1 f = 3 1 d b 2 c d 17, it takes the another the be next the lights 500 rst 20 cm are wired cm of as shown. bulb, to bulb. total length of 10 cable cm n needed Find a to connect general the nth formula bulb. for d 250 cm n 4 A a railway depot train which station. It is is then stored 6 km spends overnight from all its day in starting 10 cm 10 cm moving etc. from its along in a starting section each Explain b Find c a and The of complete a up station, why down the can 14 journey after general train Find track back its rst forth long, travels so 28 complete for the km. journey distance it of the has day it has travelled travelled after n 34 km. journeys track. travel number km it formula the and of 400 km before complete refuelling. journeys it can make before refuelling. 8.1 What comes next? 2 81 5 The 6 rst ve a Find b Show A the terms 100th that sequence a term 102 has of is a linear of sequence the u of = a formula Problem 7 A linear for the nth the u n + 1 Find + sequence 5 and u n b Write term of the A the linear Find has terms dierence down the 9 A it of until For its rst type rst linear Find The sequence the u = between value of rst the in The i 25 and is less and the ii its term number. −1. 2, 0, 4, 0 n . terms. … 65. and second is formula you 18, 4 for can 28, 40 10 4 term 103. a sequence conjecture so rst a 10 is to identify formula and the modify is a second dierences are: 40 12 2 this and 28 8 2 constant the 18 6 2 2 quadratic sequence and is related 2 Add 2 2 70. exactly. 10, 2 for = u 155, 108 that, 2, dierence than general done 2 1 u nd term. sequence 2 sequence n and 1 173, term the 0 difference the = u consecutive 2 to 25. 15 u 191, rst Having 2 2 second has nding sequence difference Second that negative describes Sequence F irst term sequence. it begins sequence step 18, sequence. 9 8 11, 1 10 Find 4, solving sequence a 3, sequence. member formula are 2 a row for n to the table: 3 4 5 6 7 8 0 4 10 18 28 40 9 16 25 36 49 64 n 2 n 1 4 2 Add another row for the dierences between n and u n n 1 u 2 2 2 3 4 5 6 7 8 0 4 10 18 28 40 n 2 n 1 4 9 16 25 36 49 64 3 6 9 12 15 18 21 24 2 n u n 2 u n gives multiples of 3. This is a linear sequence with general n 2 So 2 n u = 3n and rearranging gives n u = n 3n. n 2 Check: the rst ve terms of u n 2 8 2 8 Patterns = n 3n are 2, 2, 0, 4, 10 ✓ formula 3n A LG E B R A Practice 1 2 3 Find a a 4, 7, c 3.5, general 12, 1, 0, g 0.5, i 3, 9, k 0, 1.5, 5, b Use a 39, 24, 10, 53, … … … begins formula to sequence formula 38.5, 27, 27.5, formula quadratic b … sequence your sequence: … 18, general each 27.5, 17.5, 39, 10.5, for … 18.5, 15, 27, quadratic Find A 8, 4.5, 17, a 28, 11.5, 3, 1, formula 19, 6.5, e A 5 18, for the predict begins a Find a for the b Find the value of the c Find the value of u 4, d 2, 6, f 6, 14, h 1, 2, j 13, l 4, 20, 20, 1, 12, 8, 20, 24, 17, 30, 36, 28, 42, 50, … … 66, … 5, 10, 17, 26, … 22, 33, 46, 61, 78, 3, 0, 18, 5, 14, 12, 8, 21, 0, … … … sequence. the 3, nth 7, 15th 4, term 3, 0, of 5, the 12, sequence. … term. 20th term of the sequence. 50 4 A quadratic sequence 25, a Show that the 16th term of b Show that the 17th term is c Explain why Problem 5 begins A its the 49, sequence 58, is 65, 70, …. negative. positive. subsequent terms will be positive. solving quadratic Find all the 38, sequence rst negative begins 98, 100, 100, 98, 94, … term. ATL Exploration 1 Construct 4 dierence diagrams for these quadratic sequences. 2 a u = 3n = 2n , n ≥ 1 4, n n 2 b u + ≥ 1 n 2 c u = 5n = 2n = n = 2 n, n ≥ 1 n 2 d u + 3n, n ≥ 1 n 2 e u + 7, n ≥ 1 n 2 f u 4n , n ≥ 1 n 2 Look at the dierence diagrams. The a Describe the relationship between the explicit formula and the second coecient of 2 n is the in front number dierence. b Suggest a rule linking the coecient of n of coecient 2 to the value of the it. The of second 2 3n is3. dierence. Continued on next page 8.1 What comes next? 2 83 3 Use your rule to predict the second dierence of the sequence with formula: 2 a u = 7n – 2n = 3 8n + 1 + 2 n 2 b u n 2 c u = n – 4n n Check six your terms Example Find a begins = each 4, formula u 1 = 12, for u 2 = constructing difference the 26, = term 46, a dierence 20 the = diagram quadratic 72, u 5 46 14 of u 4 26 8 nth u 3 12 4 F irst by for the rst sequence. 4 general u predictions of = sequence which 104. 6 72 104 26 32 The Second difference 6 6 6 constant dierence 6 is second 6, so the 2 coecient n u 1 2 3 4 5 4 12 26 46 72 104 3 12 27 48 75 108 of n is 6 ÷ 2 = 3. 6 n 2 Write out the values of 3n and 2 3n comparethem to the values of u . n 2 u 3n 1 0 1 2 3 4 n Find the general formula for the linear The sequence 1, 0, 1, 2, 3, 4, ... has nth term 2 n. sequence 1, 0, 1, 2, 3, 4 , … 2 Therefore, u 3n = 2 n = 3n n 2 Therefore u n + 2 Rearrange. n 2 In a quadratic always half Practice 1 Find a a 2, 8, c 3, 12, e general 18, of the second of 32, formula 50, for the nth term … of the 3, d 8, 23, 44, 71, … f 51, 88, 135, i 2, 6.5, 13.5, 7, 17, quadratic a Find the b Find a … 23, 35, 31, … sequence next three formula for … begins 10, 16, terms. the nth 8 Patterns term. 26, each 0.5, … 2 8 4 in b 75, 1, n general formula dierence. 48, 24, A value coecient 27, 7, 1, the the 6 g k 2 1, sequence, 9, sequence. 2, 19, 4.5, h 2, 7, j 6, 17, l 3, 8, … 4.5, 0, 15, 8, 33, 7.5, 26, 34, 51, 18, 40, 57, 15.5, 12.5, … 31.5, … … 86, 25.5, … … 38, … is A LG E B R A Problem solving Draw 3 The nth triangular number, T , is the number of dots in a triangular grid of n dots n n = dots a dierence diagram. wide. 1 n a Write b Find the c Find a = 2 down n the value = 3 of n = 4 T 4 value of T 5 general formula for T n d Use your formula to nd the value of T and T 7 your answers. e Find the f Verify value of . Draw diagrams to check 8 T 15 that T is a square number. 49 4 A quadratic sequence has rst term 4 and second term 10. 2 The coecient Find 5 A the quadratic Find the Objective: ii. next select of n three in D. of general formula is 2. terms. sequence value its begins 3, x, 29, 51, … x Applying appropriate mathematics mathematical in real-life strategies contexts when solving authentic real-life Tip situations. Think ‘Select how appropriate you tackle mathematical strategies’ means, for example, that it is up to you Q6. dene draw 6 In the group stage of a volleyball competition, all the teams in the to play each other. When there are four teams in a group, you any need six any lists and or games tables. are needed Find the teams for each number exactly of once team games in a ● Can you play always each needed group Continuing D to of n for of the each other team teams to play exactly each of once. the other teams. sequences predict the next terms of a sequence? ATL Exploration In these circles, segments, n = and 1 the n The rst The second 5 this = diagram dots on divides 2 n has diagram the the 1 dot, has 2 1 circumference circle = into 3 are connected by line regions. n = 4 n = 5 region. dots, 2 regions. Continued on next page 8.1 What comes next? to variables, diagrams, group make have about whether 2 8 5 The third diagram 1 Write down 2 Predict the reasons 3 Here the your two a What is b Explain Reect ● Do the ● regions ways you the for n = would 4 and n expect = 5. when n = 6. Give could you the draw the number think is the of circle for regions correct way n in to = 6. each diagram? continue the why. 5 diagrams does you between discuss that regions. regions diagram Explain of of dierence and either of 4 answer. which prediction dots, sensible the sequence. 3 number number for are has hold t your true? prediction? Does it help If to not, look can at you the form next a term in sequence? What are sequence the in diculties in Exploration trying to nd a general formula for the 5? Summary ● A sequence Each is an number in ordered the list list is of ● numbers. called a term For a quadratic dierence is sequence, constant and the the second explicit formula 2 is ● An explicit number, ● A n, formula to recursive between one uses calculate formula consecutive term, you can the its gives the you know A general can be used general ● decrease ● For a to is where by a for a generate formula Sequences linear formula an the sequence each terms constant is term. explicit a rule that Usually the formula. increase number, = a + bn + cn In a quadratic the general the second sequence, formula is the coecient always half the of linear sequence, are The of triangular dots They needed form a formula value numbers to make quadratic describe simple the formula is of the is the sequence with form u = n 8 Patterns a and + of bn the . between explicit = 1 n = 2 n = 3 n grids. general or dierence constant in number triangular called n terms n dierence. sequences. consecutive 2 8 6 u next. ● ● form 2 relationship the the n ● When out of position value. terms. work term’s = 4 A LG E B R A Mixed 1 Find a practice formula for the nth term of 9 each A quadratic sequence begins 3, x, 15, 25.5, … sequence. Find a 6, 10, b 42, 14, 18, 22, 26, 10 35, 28, 21, the c 2, 5, 10, 17, 26, 37, d 3, 8, 15, 24, 35, … e 2.5, 11.5, 16, 20.5, Consider 2 0.5, 4, g 9, 13, h 6, 7, A 13, 7, linear 13.5, 6, its A 28, 9, 1, 4, … 47.5, Write 2 14, 17, 20, Find a below, hexagons which respectively. 3 … u = u the rst 5 n ve and u 1 = the side formula length of the rst pattern that for the 1 11 In a 610 terms. nth term of over 1000 hexagons. 12. football seats. third b patterns 3 term. formula down and … n a 2 … begins hundredth has 1, … sequence sequence honeycomb length contains 3 x … Find Find the side 1 f of … have 7, value … has stadium, The 630 the second seats, rst row and so row of has 620 on. The seats seats, has the stadium the sells seats from the middle of a row outwards. sequence. Each sell Problem A sequence has formula u = u n + 1 a tickets Write down the rst ve + 7 and u n = Find Show A linear that 85 is sequence the the completely next 15. a terms member of begins 18, 33, rst term greater than number the of the sequence. b Find front the the 48, the sold before they row. of two seats rows that are can be sold if used. number front of seats that three rows are can be sold if used. sequence. Create a formula for the total number of ... seats Find be 0 c 5 for the only only b must solving a 4 row that can be sold if the front n rows 1000. areused. 6 A quadratic sequence begins 4, 10, 18, 28, … d a Find a formula b Write down c Show that for the the value nth of sold term. the Hence seventh e term. and nd its is term a member of the A quadratic number. sequence begins 12 2, 4, A the 000 front number 30 number of rows of seats are rows that can be used. needed for the rst tickets. 12-storey stops , the the sequence 20 7 if Find 10 460 nd 10, 14, at tall every building has an elevator that oor. … 3 The a Find a formula for u , the nth term of elevator takes 8 seconds to travel one oor, the n 14 seconds to travel two oors, 20 seconds sequence. totravel b Find the value of three oors and 26 seconds to travel u four 20 Let oors. be T the time taken to travel n oors. n Problem solving a Show that T forms a linear sequence. n 8 A linear sequence has terms u 3 = 6 and u = 27. 6 b Find a formula for T n a Find the b Write dierence between successive terms. c down the value of u 7 Find the elevator greatest could number travel in of oors under 8.1 What comes next? a that the minute. 2 87 Review in context Scientic and technical innovation 1 Engineers railway are laying track. separated by They signalling place junction cable xed alongside lengths of If a you add possible cable in a third station, C, there are six journeys. boxes. A The total length of cable for 1, 2, 3 or 4 B junction C boxes Let u is 12 be m, the 18 m, cable 24 m length or for 30 n m. junction boxes. a n List the three a Find a formula for six journeys stations, A, B that and are possible with C. u n b b Use your formula to predict the length List the four cable needed for 30 junction The number of passengers, P , that would be possible with stations, A, B, C and D. boxes. Hence 2 journeys of who write down the total number of will n possible comfortably by the t into following an table n-carriage for small train values is of n: c List ve n 1 2 3 4 40 110 180 250 the journeys stations, Hence P journeys with four stations. given write A, that B, down C, would D the be and total possible with E. number of n possible a Show that P forms a linear n b Find a d formula for journeys with ve stations. sequence. Create a stations P formula on the linking network the to number the total of number of n possible c Predict the number eight-carriage train of passengers could that comfortably an The hold. Metropolitano railway, d Suggest might a reason hold more passengers 3 In a subway consists If A you and AB of a of start and then of point just the a two-carriage twice one-carriage network consider B, a why than of a 55 de of e Predict the total f Predict the number every stations, possible journeys journey end stations point. call that were built. them journeys are A B and How you have discuss explored the statement of inquiry? Give specic examples. Statement of Inquiry: Using dierent improve 2 8 8 forms products, to generalize processes 8 Patterns Lisbon’s number there BA. Reect Lisboa, underground stations. train number dierent the two has of possible journeys. train. stations, and two only the journeys. and and justify solutions. patterns can help of additional would be if possible two extra Back to the beginning 8.2 Objectives ● Factorizing Inquiry quadratic expressions, where the of two of x ● What ● What does is 1, including the dierence brackets’ mean? does ‘factorize a quadratic squares. expression’ ● ‘expanding F 2 coecient questions Factorizing quadratic expressions where mean? the coecient of x is not 1. How do the patterns in expanding C brackets help you factorize quadratic expressions? ● How can quadratic easier ● Can to patterns help expressions you in a write form that everything be written in a dierent D form? ATL Draw Reection reasonable conclusions and generalizations 8. 2 Conceptual understanding: Patterns can be represented in equivalent is factorize? forms. 9. 2 11. 2 2 8 9 MROF ● 2 Y ou ● should expand already know brackets how 1 Expand: a (x c ● factorize expressions by taking to: 2 + (x 3)(x + 3)(x 4) 2) b (x d (x 5)(x b x d 4x(3x + 2)(x + 5x + 1) 2) Factorize: 2 outa common factor a 3x + 12 2 c Expanding F To and does ‘expanding brackets’ ● What does ‘factorize quadratic an then For example: algebraic rewrite the a expression expression means without 2 7)(x + 2) symbol take the case, ≡ ≡ same 5) + 7(3x 5) factorizing What ‘expand’ The + 3x + 12 ● and (x 6x mean? to expression’ multiply mean? out each of the terms brackets. 2 x 7x means value + ‘is for 2x 14 ≡ identically any x 5x equal possible 14 to’. value of It shows the that two unknown 3x expressions variable (in this For example, any value 3(x 2) ≡ 3x 6, because the statement is always true = 17 of Quadratic an an because only it when = 4. x Exploration the true is not for x at 5 identity, x). is Look + equation, 1 following expressions: expressions NOT quadratic 2 expressions 3 5x x 14 x 5x 14 2 3x + 2x 8t 2 7w + 21 x 2 m + + 3y 4 + m + 3 z 25 2 + 3z 2z 2 2y 12 2 + 1 2 5y + 7 17 1 Based on your observations, suggest what is meant by ‘quadratic expression’. 2 Explain satisfy 3 why your Explain each whether quadratic of the expressions in the right-hand column do not description. or not you would consider (x + 3)(x 5) to be a expression. 2 x 5x whose 14 is highest a quadratic exponent expression is because it contains a single variable (x) An 2. expression highest 2 ● x 2 5x 14, x and 3x are all quadratic expressions. 3 like x ● 5x x cubic 5x 14 2 9 0 14 is is not 3, 2 4 3 ● with exponent not quadratic quadratic because because 8 Patterns its its highest highest exponent power is less is greater than 2. than 2. 5x 14, is expression. a A LG E B R A Quadratic means as a to expressions write product as of a two can be product written of in factors. expressions in a variety ‘Factorize of a forms. To quadratic’ ‘factorize’ means ‘write it brackets’. ATL Exploration 1 Copy the the 2 table. For each row, expand the brackets to help you complete table. Factorized Expanded expression expression 2 (x + p)(x + q) p q ax + bx + c a b c 15 1 8 15 2 (x + 3)(x + 5) (x + 2)(x + 9) (x (x + 3)(x 6) 3)(x 4) 3 5 3 (x 2 + 2)(x 8)(x + 4) (x )(x + 6) carefully values 3 Copy the and the 8x + 4 1 at signs table values + 5) (x Look x of a, your of a, below. b and table. b, c, p Use Describe and the any patterns you notice in the q. patterns you observed in step 2 to predict In c step 3, you shouldn’t Factorized Expanded expression expression to need expand brackets. the If you 2 (x + p)(x + q) (x + 1)(x + 7) p q ax + bx + c a b c can’t yet, 2 (x 3)(x + (x 1)(x 2) 5)(x 5) see go and a pattern back to discuss step your 8) results. (x + 4 Verify 5 Copy your and predictions complete by this expanding each factorized expression. table. Factorized Expanded expression expression 2 6 (x + p)(x + q) (x + 2)(x + 2) (x + 4)(x + 4) (x 1)(x 1) (x 6)(x 6) Describe any p patterns q you notice ax in + bx the + c values a and signs b c of a, b, c, p and q 8.2 Back to the beginning 2 91 Practice 1 Copy 1 and complete this table based on the patterns you observed assuming 2 that (x + p)(x + p q) = ax + bx q 2 + c. a 3 b 1 4 1 8 1 2 1 7 1 9 8 0 5 21 1 0 1 2 Find values such 3 N’nyree has whether you that a = concluded agree or ● How do the quadratic ● How that can is 2 1, p that = if c disagree Factorizing C c q and = 0, with b 24 = then this c either p or q is zero. Explain statement. expressions patterns in expanding brackets help you factorize expressions? patterns easier to help you write quadratic expressions in a form factorize? 2 In a Exploration = 1, c = pq 2 and you b = p found + that in all the expansions of (x + p)(x + q) = ax + bx + c, q. 2 You can use these facts to factorize expressions such as x + x 12. 2 Suppose Using x the 12 + fact and Trying x 12 that 1 c 12 each pair = (x + = pq = and in p)(x + −12 where suggests 1 turn q), 6 and p and these 2 q are possible 6 and whole pairs 2 numbers. of 4 values and for 3 p 4 and and q: 3 gives: 2 (x 12)(x + 1) ≡ x 11x 12 11x 12 2 (x + 12)(x 1) ≡ x + 2 (x 6)(x + 2) ≡ x 2) ≡ x 3) ≡ x 4x 12 4x 12 2 (x + 6)(x + 2 (x 4)(x + x 12 x 12 2 (x (x + + 4)(x 4)(x Also 3) 3) using found which has x gives the pairs ≡ of + the fact correct that b numbers sum ✓ = p + which x q makes have expression. this product process c, you more just ecient. need to Having nd a pair Tip b Always 2 In quadratic + x 12, b = p + q = check factorization 12 + 1 = expanding −11 brackets. 12 + ( 1) = 2 9 2 your 1 11 8 Patterns by the A LG E B R A 6 6 + + 4 4 2 ( + + = 2) 3 ( −4 = = 3) 4 −1 = ✓ 1 2 So x + x 12 ≡ (x + 4)(x 3). 2 To q In factorize which a have Exploration quadratic product 2 steps = x c 5 x and 2 (x You + p)(x can + p) also 2 (x + = + 6 c ≡ (x + p)(x + q), nd two numbers p and b. you expanded brackets with p = q: 2px this + p as: 2 x +2px Recognizing bx sum 2 + 2 p) perfect write + and this + p pattern can help you to factorize special quadratics called squares. Example 1 2 Factorize x + 10x + 25. 2 2 x + 10x + 25 25 ≡ (x + 5)(x ≡ (x + 5) + = 5 and 10 = 2 × 5 5) 2 If all This three makes the terms have a factorization Example common factor, taking this common factor out is a perfect square rst simpler. 2 2 Factorize 2a + 6a + 4. 2 2a + 6a + 4 2 ≡ 2(a ≡ 2(a + + 3a + 1)(a Practice 1 Factorize 2) + Take + 7x each x + 12 b g x 7x 18 e x h x 2 2 + 36 each 15 c x + 14x + 49 each 3a 18 f x + + 24 i x 6a + 3 b 5x 14 2 x + 22x + 121 c x 12x + 36 quadratic. b 4b 2 + 2b + 20e c 5c 2 3d 18 3x 2 + 3x 2 11x 2 6d + 2 7x 2 d + 2 x Factorize a 8x quadratic. 2 3 + 2 13x Factorize a 2 x 2 + factor quadratic. 2 d common 2 2 x the 2) 2 a out e 4e 10c 75 2 144 f 3f 24f + 45 8.2 Back to the beginning 2 9 3 2. 4 Find an expression for the unknown side in these rectangles: a b Area x + Area 2 ? 2 2 x + 7x + 10 x + 2x 3 ? x Problem 5 Copy and 1 solving complete, using integer values: 2 a 2 x x + 12 ≡ (x 3)(x ) b x d x 2 c x + 16 ≡ (x 8)(x ) 2 x 5x ≡ (x + )(x 7) 2 9x + 20 ≡ (x + 5)(x ) 2 10x 16 e x A rectangle ≡ (x + )(x + ) f x 5x 24 ≡ (x )(x ) 2 6 has area x 10x + 21. Area 2 x Its perimeter is 4x Exploration 1 Copy and 20. Find, in 10x + terms 21 of x, the lengths of each of its sides. 3 complete this table. Factorized Expanded expression expression 2 (x + p)(x (x + 3)(x (x 2 In 9)(x + q ax + bx in the + c a b c 9) 6)(x 6) (x + 4)(x 4) any special p 3) + Exploration a q) (x Describe gave + 3 patterns you you found pattern. notice that When expanding they are values and brackets expanded, signs in the the of a, form coecient b, (x of c, + p p)(x the 2 is 0 so there is just an x term and a constant, which is 2 In general, expanding (a + b )(a b ) 2 Any expression because 2 a it is of one the form squared ≡ 2 9 4 (a + b )(a b ) 8 Patterns a negative. 2 ab + ab b 2 ≡ a 2 b 2 b quantity 2 b a ≡ is the dierence subtracted from of two squares, another. and x q p) term A LG E B R A Reect and discuss 1 2 Explain how this diagram illustrates the factorization of 2 a b b b a (a b) a b a (a If you recognize factorize it an expression as the + b) dierence of two squares, you can easily. Example 3 2 Factorize x 64. 2 x ≡ 2 64 (x Dierence 8)(x ‘Fully + two squares, 2 x 8 8) factorize’ factorized of any Example means write as a product of expressions which cannot be further. 4 4 Fully factorize 16x 81. 2 4 16x (4x 81 2 2 ) 9 2 2 ≡ This 2 (4x − 9)(4x + is not fully factorized, as 4x 2 dierence 2 ≡ ((2x) ≡ (2x 2 3 9 is the 9) of two squares: (2x) 2 3 2 )(4x + 9) 2 3)(2x Practice 1 Fully + 3)(4x + 9) 3 factorize each expression. 2 a x d x 2 25 2 b 2 x 2 121 e j 16 1 f x 2 169 h 81x k 16 2 49x 9 4 9x 2 16x 4x 2 y g c 1 2 9 i 25u l 1 4 x 2 16v 4 81y 8.2 Back to the beginning 2 9 5 Problem 2 Copy and solving complete each identity, using integer values. 2 a 2 x 100 2 c ≡ (3x )(3x + ) b 25y 2 16a b ≡ ( a b)( a + 7b) d u 2 e ≡ ( y 4)( y + 4) 2 ≡ (3u + 2)(3u + ) 2 t ≡ Reect (3t + and 5)( t 20) discuss f x ≡ (3x + 4)(6x ) Quadratics 2 where 2 the coecient of x 2 Aishah tried learned. to Here factorize is a 3x sample + of 13x her + 12 using the methods you have 2 In the quadratic 3x In the expansion (x The sum p + q = + + b, 13x p) ⇒ + (x b 12, + = is 1 If the are called monic. work: a q), 13, = 3, the and b = 13 product so p = 1 and pq and c = = c, q = not 12. ⇒ c = is 12. 1, coecient the is quadratic non-monic. 12. 2 Therefore, ● Is ● Why doesn’t ● How is Aishah’s 3x + 13x + factorization this this 12 (x + correct? method expression ≡ work 1)(x Is it for dierent + 12) equivalent this from to the original expression? expression? the other expressions you have factorized? 2 To have 3x as the rst term of a quadratic expression, the factors need to start 2 with The terms that factors second Look of term at the multiply 3 in are 1 each and make 3, bracket examples Example to below so 3x the can be and factors found then need by to start listing attempt (3x ) and possibilities Reect and (x ). The systematically. Discuss 3. 5 2 Factorize 3x + 13x + 12. 2 3x + 13x Pairs 1 of and 12 + 12 ≡ values (3x ) with ) product 12 and (x 1 12 are: 2 and 6 3 and 4 6 and 2 4 and 3 2 (3x + 1)(x + (3x + 12)(x 12) ≡ 3x ≡ 3x + 37x + + 15x + 12 2 + 1) 12 2 (3x + 2)(x + 6) ≡ 3x + 20x + + 12x + + 15x + + 13x + 12 2 (3x + 6)(x + 2) ≡ 3x (3x + 3)(x + 4) ≡ 3x 12 2 12 2 (3x + 4)(x 2 9 6 + 3) ≡ 3x The 8 Patterns 12 ✓ numbers in the brackets have product 12. A LG E B R A Example 6 2 Fully factorize 6x 7x 10. 2 6x 2 = 3x × 2x = 6x × x, so 6x 7x 10 = (3x ) (2x ) 2 Find terms with product 6x 2 or 6x 10 7x = −10 10 × 1 = = (6x −5 × ) 2 = (x −2 ) × 5 = −1 × 10 Find numbers with product 10. 2 (3x + 1)(2x 10) ≡ 6x 28x 10 11x 10 2 (3x + 2)(2x 5) ≡ 6x (3x + 5)(2x 2) ≡ 6x 10)(2x 1) ≡ 6x 2 + 4x 10 + 17x 2 (3x + 10 Try the terms and numbers systematically. 2 (3x 10)(2x + 1) ≡ 17x 6x None 10 of these is correct. 2 (3x 5)(2x + 2) ≡ 6x 4x (3x 2)(2x + 5) ≡ 6x 10) ≡ 6x 10 2 + 11x 10 + 28x 10 2 (3x 1)(2x + Since 3x and 2x did not work, try terms 6x and x 2 (6x 10)(x + 1) ≡ 6x 4x 10 2 (6x 5)(x + 2) ≡ + 6x 7x 10 Nearly correct; try +5 and 2 2 (6x You + 5)(x may not 2) ≡ need 6x to 7x write ✓ 10 down all the possible factorizations to test them. 2 Each one gives expanding the gives correct the correct Reect and ● factorization Which What made x and middle discuss them constant so you only need to check if term. 3 was easy terms, easier: or the one in Example 5 or in Example 6? dicult? 2 ● A student (3x ● + Why 5)(x do tries + you consuming Practice Fully 2). to factorize Show think way to that 3x the listing the tackle this + 17x + middle 10 term options and is gives the answer incorrect. systematically might be a time- problem? 4 factorize each quadratic expression. Tip 2 1 2x 2 + 5x + 3 2 3x 2 + 7x + 2 3 3x + 7x 6 Write down working to enough be sure 2 In Example constant explore identify 6 there term, which another the are way factors two gives to possible a lot of factorize straight pairs of possible quadratic away. factors factors for to the test. expressions x term You where and will it is the you now not easy have answer. to the correct Look opportunities for to be ecient: it’s do working some your 8.2 Back to the beginning OK head. 2 97 to in Exploration To expand a pair multiplication. every (2x + term in 3)(x 4 brackets, You the 4) of ≡ you multiply rst use every the term distributive in the property second of bracket by bracket. 2x(x 4) + 3(x 4) If you use a 2 ≡ 2x 8x ≡ 2x + 3x 12 dierent method for 2 5x 12 expanding check 2 1 Use 2 the The distributive table shows Working from brackets. The property ve left top to dierent to right, row has show that quadratic each been cell (2x 1)(x + expressions, shows one completed. step Copy 5) ≡ one in and 2x on + each complete + 3)(x (2x 3)(x + 4) = 7) = 2x(x 4) + 3(x 4) = 8x + 3x 12 = = = 3x(2x 1) + 4(2x the table. 2x 5x 12 5x 4 = = 1) the 2 2x = 2 = = = = 4x + 12x 2x = 6 2 3 Explain to 4 which you think is easier: = completing from left to 6x + right or right left. Comment why it is on which harder of than the the steps is most dicult to complete. Explain others. 2 5 Two students try to factorize the expression Carmen 2 + 25x Explain Exploration splitting the happens help In 4 B. or rule. more 6x 25x you 2 + 21x + student’s shows that term kind 5 you Then you of 6x helps make correct some + 14. 2 + to a 25x + 14 factorize quadratic way. factorized ≡ 6x + the + 5x + 14 expression. easier Exploration expressions 20x to 5 to factorize by investigates nd a what pattern to quadratic. patterns general gather should 14 can justify, should + work the Investigating and 4x you in expand this verify Exploration few ≡ which factorize prove, general 14 middle Objective: iii. + when you + Miranda 2 6x 6x rules enough verify it, by information showing that so you your can conjecture conjecture holds a for a examples. Exploration 5 ATL Investigate the relationship between the coecients of the split middle term 2 and To the coecients work out examples, how you in to could ax split + bx the make a + c middle table term like of a quadratic by studying 2 9 8 8 Patterns some this: Continued that it gives 5. the same (2x + result row . expanding 2 (2x 9x brackets, on next page 3)(x 4). for A LG E B R A You Coecients Factorized Coecients Expanded of the split middle more + ax expression expression can bx + information c term by a gather in 2 b making up your c own examples 2 (2x + (2x + 3)(x + 4) 1)(x 2x + 3x + 8x +12 3 8 2 11 12 for the left-hand column. 2) make You new can examples ... by Add nd more the rows until product and you the discover sum of the the pattern. You coecients of may the nd split it useful middle to changing numbers term. examples already This skill Reect and discuss in is you been an what Example you found have given. important when 4 investigating Compare the the in Exploration 5 with others before moving on. in mathematics. 7 2 Factorize 15x 2x 24. 2 15x 2x 24 Find two numbers with product 15 × −24 = −360 and sum 360 = 18 × −20 2 = 18 + −20 24 ≡ 15x Split 2 middle term into 18x 20x 2 2x 15x + 18x 20x 24 Take Does the the order factorizing the ≡ 3x(5x ≡ (3x of + 6) 4(5x 4)(5x the + middle quadratic in + the common factors 6) (5x from + 6) each is a pair of terms. common factor. 6) terms matter? Example Look at these two ways of 7: 2 15x 2x 24 2 2 + ≡ 15x ≡ 3x(5x ≡ (3x They 2. 18x + 6) 4)(5x both 20x 4(5x + give 24 ≡ 15x 6) ≡ 5x(3x ≡ (5x + 6) the same 20x + 4) + + 6)(3x 18x 6(3x 24 4) 4) factorization. 2 Quadratics where the coecient of x is not 1 may be factorized by 2 splitting whose the sum middle is b and term. To whose factorize product is ax + bx + c, look for two numbers ac 8.2 Back to the beginning 2 9 9 Practice 5 Problem 1 2 Find pairs solving of numbers a product 240 c product 96 Find values and and to ll which sum sum these have: 32 b product 180 35 d product 1000 boxes and complete the 2 a and sum and 3 sum 117 identities. 2 x b x 4x + 2 27x + 2 = x + = 5x(2x = ( x + 4x 7) x 14 (2x )( x + + x = 7) ) + = x(4x = (x + + 3x + x 3) + (4x )( x + + + 3) Use ) any methods 3 Factorize each learned. quadratic. 2 2 9x a 5x d 6x g 6x + 4 b 6x e 8x h 6x 2 + 4 j 15x m 2x 5x + 1 7x 2 k 8x + 1 n 2x + 7x 15 q 4x 2x 3 t 7x 14x 3 Problem These could w expressions ll 3x x 2 i 6x the x can empty + Can 17x + 6 5x 1 + 10x 3 l 21x o 15x 23x + 6 2 9x + 10 40x 15 2 + 8x 21 r 12x u 8x + 4x 5 2 16x + 4 + 24x + 16 2 9x + 11x + 2 x 10x x 21 be factorized. Determine the dierent b everything the values that boxes. 2 Exploration Factorize 3 2 2 + ● 1 12x + 2 + x 2 + 9x Non-factorizable D f 8x solving 2 a 15 2 5x + 2 14x 2 2 4 4x 2 2 v c 2 3x 2 5x 2 2 2 s + 2 + 2 4x 7x 2 11x 2 p 2 + be + 2 c 6x + 10x + expressions written in a dierent form? 6 following expressions if possible. Verify your solution by expanding. factorized form factorized form expanded 2 x 16 2 49x 121 2 x + 25 2 25x + 81 2 4x + 9 Continued 3 0 0 8 Patterns on next page of the you have A LG E B R A 2 Describe anything you notice about the expressions you could not Tip factorize. Explain Factorize the why they are not factorizable. If 3 following expressions if possible. Verify your you yet by have not solution learned how expanding. to factorized form factorized form multiply brackets expanded in step out like 5, those either use 2 x + 6x + 4 a computer algebra 2 2x 3x system 1 it as a or complete group with 2 x – 10x 24 your teacher’s 2 x + 10x + 24 assistance. 2 4x 4 + x 10 For those why 5 the methods Expand these Describe Reect ● When When other using are if that that power you as take HL Fundamental + 3 + cannot learnt 5 )( x factorize, did + 3 − not explain clearly work. 5 ). expression be you factorized you of can not of be factorized work with algebra be in ‘not factorizable’, integers. we What other as set You part algebra says is of that of any there quadratic numbers. learn the integers, althoughitmight real will using are quadratics. factorized, the numbers. Mathematics is using use? cannot help are theorem not 5 theorem which could already quadratic could complex you notice. polynomial) numbers known a it will Fundamental higher (x expressions techniques The you that numbers quadratic have discuss say mean of you anything we which brackets: and usually types expressions about Diploma. university-level These numbers complex Proving (or involve numbers the mathematics. Summary 2 ● The It symbol shows ≡ that means two ‘is identically expressions take equal the to’. ● Where one same the coecient method of of x factorizing does not involves equal listing 1, all 2 value for any possible value of the the unknown. pairs pairs ● To factorize a quadratic written in the of of terms numbers with with product product ax c. and Then all try the the form dierent combinations until you nd pairs 2 x + bx + c ≡ (x + p)(x + q), nd two numbers which p and q which have product c and sum ● 2 ● Any expression of the form a Alternatively, is of two 2 a quantity squares, because subtracted is often quicker to look for the it is numbers from whose sum is b and whose one product squared it 2 b two dierence work. b. is ac another. 2 b ≡ (a + b)(a b) 8.2 Back to the beginning 3 01 Mixed 1 practice 6 Factorize: Factorize: 2 2 a x c x e x g x i x k x 2 + 4 x + 4 b x − 13 x 2 a a c c e 4e g 3g 5a 36 b 16b d 4d f f h 16h 2 2 2 + 5x − 14 d x − 7x − 8 f x h x + 18 x + 81 − 11x + 24 − 15 x − 100 + 11x − 42 2 + 11c + 24 2 2 9 + 36 17d 2 3e + 2f 2 2 23g + 100 2 Problem 2 + 4 x + 3 j x + 4 x − 96 l x 2 7 2 + 7x 2 Ornella Factorize + 56 n x of a whole result, number, and adds subtracts four to 9. − 11x − 60 By letting the original anexpression number for this be n, write process. fully: b 2 Hence show the number that Ornella obtains 2 x 49 b x 169 can 2 64 always be written as the product of two 2 x d 25 x integers 4 2 e the 2 − 15 x down c 1 solving thinks squares a a 14 + 6 it, 2 + 2 − 20 x x 48 2 2 m 15 8 2 144 x 81 f 256 x Copy and with a dierence of 6. complete: 169 2 2 g 2 4 x 2 y h 16 x a x b x x + 15 ≡ (x 3)(x ) 2 9 y 2 2 i j 289 y x + 20 ≡ (x + 4)(x ) 4 2 25 x x 16 2 4 k 4 16 x 1 l c x d x 8x ≡ (x + )(x 11) 4 9x 729 y 2 3 Factorize 9 2 a 2x 11x 2 + 8x + 6 b 2x + 14 x Dagmar it, + 20 and 2 2x e 2x ≡ thinks (x of subtracts number c + 5)(x ) completely: in the an 1. even By form number, expressing 2n, or squares his original otherwise, show that 2 − 12 x + 10 d 3x f 3x − 9x + 6 the result product 2 of of this two process can consecutive be odd written as the integers. 2 + 8x − 24 + 21x − 24 3 10 2 g 4 x You have two − 8x − 32 h 2x − 2x − 40 one measuring measuring 4 rectangular grids of 1 cm cubes, 2 n + n 3 + 1 by by n + n + 6 cm, 3 cm, and where n the is other a Factorize: positive 2 a 2x c 2x e 5x integer. 2 + 5x + 2 b 2x 3x + 13 x + 20 n 2 + 6 n + 12 d − 12 x + 4 f − 8x 7x + 38 x − 24 n n + + 3 1 2 2 6x 3 − 3 2 2 g + 2 − 11x + 31x + 5 h 6x j 8x − 17 x + 5 − 41x + 5 2 2 i 8x + 18 x + 9 2 k 9x 2 + 12 x − 32 l 10 x − 13 x − 30 a 5 4a 3 3a and number 2 a Find simplify an expression for the total 3 Factorize: b 7b 2 35b grids 168b b of 1 cm cubes in the two rectangular combined. Show that if you take apart the rectangles 3 and recombine always cubes left simply 3 0 2 8 Patterns be be able over a the to 1 cm form (where straight a cubes rectangle the line you rectangle of cubes). will with will no not A LG E B R A 11 A rectangular nmeters on sports each pitch side. has The a border total area They of occupied repeat number of the process, rows as adding before and the the same same number 2 by the pitch and its border is 4n + 28n + 45. of columns as before. Now the grid contains 112cubes. n They repeat resulting repetition, n Pitch the grid there Construct sequence a 8, dierences n follow the dimensions are a third 209 336 time, cubes. cubes in and After the a the nal grid. n a Find process contains of the a dierence 45, and 112, 209, show quadratic diagram 336. that showing Analyze these the the numbers sequence. pitch. b Letting u be the number of cubes in the nth n 12 Start with a rectangular grid of 8 grid cubes: (so u = 8), nd a formula for 1 u in the n 2 form 2 4 an + bn + c rows columns c Factorize your formula for u . n d Hence determine columns Somebody columns many grid else to the they’ve now then grid, adds but added. contains Reect and How have you Give specic 45 some doesn’t They do extra tell tell rows you you being the added number each of rows and time. and how that the cubes. discuss explored the statement of conceptual understanding? examples. Conceptual understanding: Patterns can be represented in equivalent forms. 8.2 Back to the beginning 3 0 3 9 Space The frame of geometrical dimensions describing an entity Dimensions We live located in a using dimension, We a can three people imagine mirror, familiar space three-dimensional is or order with Cartesian There a is a the could of a a can longitude be 2D on the coordinate plane, that and at altitude. any universe plane named everything These to after the be images create our Letting particular would in and if possess graphs. French time place like, world This we no be can the be 4th moment simply in look thickness. scientist into You representation philosopher, time. of are 2D and Descartes. point book in 3D written Dimensions, mysterious and located ground. three-dimensional A meaning two-dimensional Cartesian Many exist objects the wonderful encounters 3 0 4 locate latitude, shadows Rene plane. Romance b eing what using called to and observe mathematician In aspects: world, visitor what it objects, would over about from might a the look therefore hundred a we need have years third like. dimension add three ago two-dimensional to by third axis coordinates Edwin world and a Abbott where struggles one to of to the instead of two. called Flatland, its inhabitants comprehend how such a Animation Have you ever understanding achieve the use this of barycentric the the effect. how Therefore, in coordinates, is and that effort it animated three-dimensional or large are the using simplies complete the characters space part of that this different using the a can we look live modern so in process of set and of and move in gures. coordinates, triple uid success animated harmonic coordinates greatly to a creating mathematicians method time of mathematics animations, this wondered To is create are numbers. a in An essential animations which animating real? a The is your form due to favorite of advantage character, to and of reduces animation. More In the on than 1990s, the string discovered at least But theories any dimensions does this number including spaces. If the then than ten of in there being existence. mean? always worked dimensional innite mathematics explaining more of working physics really have spaces, universe, of likelihood Mathematicians with dimensions mathematicians the ten what 3 is inherent perhaps dimensional capable of structure there dimensions are of our even waiting to discovered. 3 0 5 be Spacious interiors 9.1 Global context: Objectives ● Finding the (including ● Finding Inquiry surface area pyramids, the (including Personal volume of pyramids, of cones any cones any and 3D 3D ● shape F spheres) What is SPIHSNOITA LER ● expression What the How dierence between area and area? are some cylinders, spheres) cultural questions surface ● shape and and are properties pyramids the surface and of prisms, cones? areas of pyramids, C cones ● D ATL Is and there a spheres best related? method for nding volume? Creative -thinking Apply existing knowledge to generate relationships measurements construction activities for enables and and products or processes between the analysis ritual ideas, 7.3 Statement of Inquiry: Generalizing new of 9.1 play. E9.1 3 0 6 G E O M E T R Y Y ou ● should use already know Pythagoras’ theorem how In A N D T R I G O N O M E T R Y to: each triangle, missing answer side. as a If nd the length necessar y, give of the your radical. 1 a 5 m 5 m 2 41 9 cm cm b ● nd area the of volume cuboids, and sur face prisms and cylinders Find each the volume solid. answer to If 3 and sur face necessar y, signicant 4 cm cm 5 3 of your gures. 6 3 area round cm cm 4 12 8 5 4 m m mm Ara 6 3.5 mm 4 2 ● nd the length area of an of arc a sector and 6 Find and the the area of length 8 of a trapzium: mm mm mm the of shaded its sector arc. cm 110° 9.1 Spacious interiors 3 07 Proper ties F ● What is ● What ar Exploration 1 Mak a list of 2 Mak anothr th of 3D dirn som solids twn proprtis of ara prisms, and surfa ylindrs, ara? pyramids and ons? 1 shaps list of that hav shaps an that ara hav that a you surfa an ara alulat. that you an alulat. 3 Nxt to ah 4 Compar and dirns A only in is plan stp ontrast twn polyhedron has shap a 3D (at) 2, th th shaps ways solid stat of th in numr ah list. alulating A that pyramid A cone irular A on is a 3D as is solid and not a an with apx A a or (th A You alrady ylindrs volum know and of pyramids, Th surface Th volume 3 0 8 how prisms. area of a to nd th surfa Now you will ons and sphrs. is th total ara 3-dimnsional 9 Space look of all solid is th Th mt othr at is a 3D ar distan) and not a of a amount a fas ar alld polyhdron. with points on on th quidistant from of surfa th ntr. uoids, ara and 3-dimnsional of a polyhdron. volum th with point is solid surfa is a and ara. solid th nding fas 3D All sphr th a similaritis surfa pyramid fa. sam ara at A sphere sphr’s polyhdron. is that apex. urvd vrtx. fas. and as. triangls th its Idntify ara polygon fas. of spa it solid. oupis. G E O M E T R Y Exploration Copy 3D and A N D T R I G O N O M E T R Y 2 omplt this tal with your osrvations aout th dirnt solids. Prism ● any Cylinder Pyramid Cone shape, often a regular polygon ● rectangular based prisms Base are called cuboids ● two opposite faces each could be the base ● always ● the a circle Crosssame section radius parallel the the as to base all base along the cylinder ● triangles ● if is the a base regular polygon, the triangles Sides are all congruent ● the triangles meet at all the apex Reect ● ● and How is a How is it How do givn its discuss sphr similar 1 to th 3D solids in th tal in Exploration 2? dirnt? you think th dirns volum ompard and to surfa othr 3D ara of a sphr is found, solids? 9.1 Spacious interiors 3 0 9 Finding C ● Sur face How th surfa area aras of pyramids, ons and sphrs rlatd? area Pyramids, surfa ar sur face ons and sphrs ah rquir a dirnt mthod for nding ara. Apex Th slant distan as to height from th of th apx a pyramid ntr of th of is on th dg of th Slant height pyramid. Vertical height Th vertical distan height from th is th apx prpndiular to th as. ATL Exploration 3 Tip 1 a Dtrmin whih 2D (at) shaps mak up th 7 dirnt fas of this squar-asd cm Th pyramid. ar b Idntify th information you nd to nd th 7 four triangls isosls cm ongrunt. surfa ara of squar-asd pyramids. 10 2 a Us th information nd th ara of th givn as in of th diagram pyramid cm to A. 10 b Justify whthr th information in cm th Pyramid diagram th 3 is nough triangls c Calulat a In on th pyramid to th sid surfa B, th nd th of ara ara th of of on A of pyramid. pyramid sid of th squar hight of th pyramid A. as Apex and th givn. vrtial Suggst how you ould ar Slant height alulat Vertical height th slant hight of th pyramid using this information. b Find c Us th slant hight of th pyramid. 6 ara th of slant on hight of th to alulat triangular cm 6 th fas of th Pyramid pyramid. d Hn 310 nd th total 9 Space surfa ara of pyramid B. B cm and G E O M E T R Y Example Find th A N D T R I G O N O M E T R Y 1 surfa ara of this rtangular-asd 6 cm pyramid. 10 of as = 8 × 10 = 80 cm There are three dierent side areas 2 Ara 8 cm m to nd; the rst one is the rectangular base. 6 cm Use Pythagoras to calculate the slant height s 1 6 cm s for the front and back triangular faces. 1 8 2 s 2 = 4 cm cm 2 6 + 4 = Us s and h for slant hight 52 1 ⇒ = s m of front vrtial hight. 1 Ara for triangl The area of the back triangle is the same as the front triangle. Note: keep answers exact (using radicals) at each stage. Use your calculator only at the end to give your nal answer Similarly, alulat th slant hight s for th 2 lft and right 2 s = 6 triangular correct to 3 s.f. fas: 2 + 5 = 61 2 ⇒ The area of the right side triangle Ara of lft triangl = is the same as the left side triangle. Total ara = = ara of as + 2 tims th ara of front + 2 tims th ara of sid 80 + 2 × 10 + 2 × triangl Find the total area of all 5 faces. triangl 4 2 = Reect ● 215 m and Compar ● How do pyramid you ● How as would hxagon as ontrast pyramid think with hxagon) s.f.) discuss and squar-asd (3 its prosss a for nding rtangular-asd ompars rgular to nding polygon (for th th surfa ara of a pyramid. surfa xampl, a ara of a pntagon or as? you its th and this anothr 2 nd as? th ara How of would th as you nd of a th pyramid slant with hight of a rgular this pyramid? 9.1 Spacious interiors 31 1 Th S = surfa A + ara You Find 1 th 4.5 4 with an n-sidd rgular polygon as is 1 qustion, may pyramid triangl Practice ah a nA as In of nd opy to surfa th draw ara diagram and omplt mor diagrams for ah pyramid. If of m it dirnt as stps nssary, 5 2 you solv in round th th prolm. solution. your answr to 3 s.f. cm m 4 m 5 5 cm cm 3 6.5 cm 3 6.2 cm 5 4 This dg cm cm squar-asd masurs 8 pyramid has four idntial 8 5 th b Hn Problem 5 A th Gorg Egypt. Gorg 7 wants b Hn, surfa a a m m ara. of 48 paint whih pyramid solid whit is to nd 3D ara hight Explain This is ought a m solving surfa Its has th ara a all four ttrahdron plastr mm fas th a with rplia and th with of sid pyramid in th pyramid of th surfa as with th quilatral sid lngth Grat lngth of h of nds th 7 triangls. m. Pyramid its ston-olor of squar fas squar to to mak on his as it m Find and its total surfa ara 2400 pyramid that h . cm 30 312 9 Space to mm. mor nds hight. 30 trip 75 ral. paint. sid m is look 2 30 sloping hight. its ttrahdron Find 6 slant nd Eah m 5 Find fas. m. 8 a triangular cm to paint. G E O M E T R Y 8 Ths two squar-asd pyramids ar mathmatially A N D T R I G O N O M E T R Y similar. Whn sal ara 4 th linar fator sal is r, th fator 2 cm 6 4 is cm cm 6 Pyramid A Pyramid r cm B 2 Pyramid A Calulat Th surfa unravlld has th ara into surfa surfa of a a ara on irl ara of with and a 64 m Pyramid as B. radius r and slant hight s an stor: 2πr r s Th ar lngth 2πr. Th Th formula of radius th of major th that stor stor show th is is qual qual to to th rlationships th slant in a irumfrn hight irl s of th of th irl, on. ar: 2 Ara of a irl = Ara of a stor πr θ 2 π s = 360 θ Ar lngth of a stor 2π s = 360 Howvr, you Thrfor 2π r know that ar lngth l = 2πr θ 2π s = 360 360 r ⇒ θ = s And th ara of a stor 360 r s 2 π s = 360 r 2 π s = = π rs s 2 Thrfor th surfa ara of a on = πr πr s + 2 Th surfa th radius th on. ara of th of a as on and = s πr is + th πr s whr slant r hight is of s Th urvd surfa ara of th on is πr s r 9.1 Spacious interiors 3 13 Practice Find th 2 surfa 8.1 ara of ah solid on. If nssary, m 5 13 1 3 Th diagram Calulat shows th ara th of round your 4 Blgium from pag is famous his loal a Draw b Dtrmin nd c a th Find 3 s.f. cm m dimnsions papr usd to of a papr mak th up. 6 cm up. cm solving nwspapr. of to cm 9 Problem answr for its Rn Frnh maks nwspapr. diagram th to show largst a fris, papr Th th pag whih on masurs smiirl possil ar on diamtr oftn from of a 410 th th srvd smiirl mm pag y of in ons ut 315 from mad a mm. nwspapr. smiirl. Hn, radius. th ara of th largst on Rn an mak from a pag 4 m. of this nwspapr. d Find th e Hn, irumfrn nd th radius of of th th irular as of as. th papr on. 2 5 A solid on has surfa a Find th urvd b Find th slant c Hn, As th irls ara (whih hav as no mor Reect Suppos sam into ● small How pl ● straight dgs for at th pis, many ara th is of th and as radius on. of you not th on. annot Finding possil us th with th sam surfa mthods mthods ara that of a you for nding sphr know and 3 an orang Suppos ompltly irls svral you lld would thn as you tims, pld many xpt of to rating th th ll irls orang, irls with as th with raking th it possil. orang pis? How dos this dmonstrat th formula 2 Th , mathmatis. around th m on. dgs, orang. and of hight discuss trad as 125.7 polygons. all) advand you of vrtial would and radius surfa hight th no you has rquirs nd ara surfa 31 4 ara of a sphr 9 Space = 4πr for th surfa ara of a sphr? G E O M E T R Y Practice Find th T R I G O N O M E T R Y 3 surfa ara of ah sphr. If nssary, round your answr to 3 s.f. 2 1 radius = 2 cm diameter 3 A N D Calulat th surfa ara of ths = 24 cm solids. b 5 cm 4 a cm 9 Problem cm solving 2 4 Th surfa 5 How dos ylindr ara th in of ● Is sphr surfa whih it Finding D a thr ara ts is of 400 a m sphr prftly? . Calulat ompar (Diagram to its radius. th shown at surfa ara of a right.) volume a st mthod for nding volum? ATL Exploration Arhimds a similar You Part 1 1 Put so 2 – disovrd mthod will ylindr nd and a that golf th Rord watr th volum of a sphr in 225 bce, in watr), and you will us hr. golf all (or any all that sinks a masuring watr. nding th 4 the all in watr th volume th a golf masuring ovrs watr of lvl th and ball ylindr. Fill th ylindr with watr all. alulat th volum of th all and th togthr. 3 3 Rmov volum 4 Us th of your golf th all. Rord th nw watr lvl, and alulat th 1 ml = 1 m watr. rsults from stps 2 and 3 to nd th volum of th golf Continued all. on next page 9.1 Spacious interiors 31 5 Part 5 2 – comparing Th diagram Th radius a Stat shows of th spheres a golf radius a golf all of and all is th cylinders in a ylindr. approximatly 4.2 4.2 m. cm Whn ylindr ts b Stat th hight of th Masur nd golf th th diamtr volum all with of th its of th golf all irumsrid volum of its that you ylindr. irumsrid usd in stp Compar ylindr. 1. th Us this volum Us your of to th ndings th possil th suggst Arhimds and formula of invntor. tomston, In a Exploration Syraus It to for is said 4, th (287 h rprsnt th volum bce had his volum a – 212 sphr favourit of of th a sphr. bce) was a Grk irumsrid mathmatial sphr is y mathmatiian a ylindr on his proofs. two-thirds of th volum of its 3 irumsrid 2 ylindr, 4 (2π r = and 2πr . Two-thirds of this volum 3 Th You volum π r ) = 3 has 3 3 is whih volum an us volum a of a sphr similar of a mthod to vrify th formula for volum of a pyramid on. Volum of Volum of uoid: l pyramid 1 × w × with sam as × h ara = ara of of as × as × hight hight 3 and h hight: l w This formula an gnralizd to a pyramid with any as. 1 Similarly, th volum of a on is th volum of a ylindr with th sam 3 as radius and hight. 1 Volum of on = × volum 3 h 1 2 V π r = 3 r Volum of pyramid Volum of on 316 = × 9 Space ara of as × hight h of ylindr smallst ylindr, ylindr circumscribes sphr. to sphr ylindr insid 6 a prftly th G E O M E T R Y Practice Find th volum of ah 10 3D solid. 2 cm 6 7 cm 8 cm cm 3 24 4 7 cm cm 6 cm cm 24 10 12 5 cm cm cm 6 7.4 10 8 10 In cm cm 7 10 cm cm 8 8 T R I G O N O M E T R Y 4 1 8 A N D Prati 2 6 9 cm 18 cm cm Q4, you found th ara of a nwspapr on mad from a smiirl. a Find b Explain th lss volum why than Problem 11 Ths of th this nwspapr volum of potato answr to part your on. in this on of Frnh Fris would a solving two ons ar mathmatially similar. Whn 3 Con A has volum 2000 sal 10 Calulat th volum of th linar m Con cm 12 fator volum Cone A Cone is r, th cm B. sal fator B 3 is 12 a Explain b Th why any two sphrs ar mathmatially r . similar. 3 volum Find i th of a sphr volum radius 8 of a of radius sphr 4 m is 268 (to m 3 s.f.) of m ii radius 2 m 3 13 Find th hight of a on that 14 Find th radius of a on 15 Find th radius of a sphr 16 Suppos has volum 270π mm and as radius 9 mm. 3 that has volum 8.38 m and hight 2 m. 3 mpty Find you ll ylindr th answr hight as a an mpty that up has th fration of with sphr th sam ylindr th volum total with 523.6 watr hight that th hight and and th thn diamtr watr of m would pour as it th rah. into an sphr. Lav your ylindr. 9.1 Spacious interiors 317 Summary ● A polyhedron (at) is a 3D solid that has only plan ● fas. Th surface fas ● Th of a Th of of a spa surfa rgular is th total 3-dimnsional volume amount ● area ara polygon ara ● A pyramid as. Th is a 3D othr solid fas ar with a Volum of th solid is th oupis. of a pyramid as is S = with A + pyramid = × ara of an n-sidd nA as ● all solid. 3-dimnsional it of triangl as × hight polygon triangls that mt h at a point alld th apex. A pyramid is a polyhdron. 2 ● Surfa radius ara of th of a on as and = s πr is + th πrs s h ● A cone an is apx a or 3D solid vrtx. A with on a irular is not a as and polyhdron. r ● Volum ● Surfa of a on 2 ● A sphr is a 3D solid with on urvd ara of a sphr = fa. r All th points equidistant A sphr on (th is th sam not a sphr’s surfa distan) from ar th ntr. polyhdron. ● ● Th slant from th apx of height ntr th of of a pyramid on dg of pyramid. Slant Height height 318 9 Space is th th distan as to th Volum of a sphr 4πr whr slant r is hight. th G E O M E T R Y Mixed A N D T R I G O N O M E T R Y practice 2 1 Find 3D th surfa ara and volum of 3 ah A on radius solid. a 12 b cm 6 has 5 surfa ara 204.2 m cm 4 12 c 9 3 5 cm as cm cm cm cm cm and m. 5 12 , cm a Find th slant hight b Find th volum of of th th on. on. d 3 cm 3 4 Th volum Aording of th all to 5 e A sor th sphrial all is rgulations, twn whthr rgulations. cm a must Determine 1 of Justify soop this i th 68 dm . irumfrn m sor your of 5.6 and all 70 m. satiss th answr. ram is ut in half, and f ovrd in hoolat (inluding th at fa). 2 Th a 6 16.4 cm total Find of cm b ara th i 6 solving Hn, Two Th 2 All ight dgs of a squar-asd pyramid m radius nd papr in of th is 85 m sphrial soop th volum of th i ram hoolat. ons apaity of ar th mathmatially largr on is 8 similar. tims th ar apaity 12 hoolat ram. ovrd Problem of of th smallr on. long. Th surfa ara 2 th smallr Find th on surfa is 50 ara m of . th largr on. 12 cm 12 cm 12 cm a Find its surfa b Find th surfa mathmatially as a ara squar of and ara and similar sid its 9 volum. volum pyramid, of a with m. 9.1 Spacious interiors 319 of Objective: ii. slt In these surface D. appropriat real-life area of Review Th as th pharaohs. select to the answer in ral-lif stratgis strategies the ontxts whn you have solving learned authnti for cultural uilt squar-asd urial Th ar ritual thr for largst loatd Many liv inund y a th pyramids quns and a Find and st i in th town of th that th Goldn of Giza, sids of th as masurs 230.4 th mtrs Find 3 masurs 145.5 mtrs. th ratio of sid lngth to whil How hight th is Th ara c a pyramid layr of of th was whit limston Compare th rlat d ara to of th Calculate Calculate to gam pyramid originally limston. ovrd Calculate was Nar in th as total th th surfa squar ara as. of primtr as th radius Describe of th is th of How dos , hoop Th Srpnt, what on usd with m th to as th you of gan dorat 12.5 a yllow and How you a A allgam, vry larg arhaologial Playrs havy on of ity a of hundrds of sit ould all through nd a ring th wall of th Gnralizing analysis m. and Th matrial ativitis surfa why ara in putting nding tradition of in Grmany in onial thm (No of ourt of th th th all th all (no ring was through gam. dorating th and th vrgrn 9 Space njoy it 16th was ntury . thir wr possil With auty put from to all undrnath th fa.) a of th a aout Determine ara for m whih tr dorations: and a or tr a would on maximum with a hav with a mor hight of irumfrn hight of 180 of m and a th of irumfrn of 210 m? Justify A in Rokfllr your answr. pyramids found ranging sphrs alld tr loatd ritual Cntr in Nw hundrds City is lit vr y yar in arly Dmr. from largst tr masurd 100 ft tall and wr a volum quivalnt to 65 500 ui ft. jarosit. statmnt twn for shap, dorations th ara was discuss rlationships of irumfrn Totihuaan. root xplord th th of inquiry? Giv spi xampls. Statement of Inquiry: 320 sport, th of hight noti Tmpl irumfrns to Reect and th Mxio. If rsultd roughly Find hav in justify thir had in at gtting and trs Th ovrd Itza Christmas Y ork 3.5 ah this pyramid. irumfrn qual Th Msoamrian sphrs for sids b aout tam Msoamria. visil vrtially m m 215 City Arhaologists of ndd Ratio? volum wll a Mxio th lay arlist allowd). 95 2830 rsults. Fathrd in y 200m 2 of 2 th usd. Goldn th with pyramid. ths all. th irular irl th still Chihn sids. e paint: los 4 to to largst Ratio? ntir with ndd th th hands b volum playd mountd Goldn ii Grat th is jarosit all. Potntially of hight of all wr (1.62). of amount smallst nar ourt Pyramid and prsrvd uildrs Ratio th th was Eah volume expression siz Cairo. the situations questions. b pyramids nding ral-lif context and of mathmatial shapes Egyptians part mathmatis situations, 3D in Personal 1 Applying masurmnts and play. nals th onstrution availal for dorations. A parable about parabolas 9.2 Global context: Objectives ● Finding the quadratic ● forms: axis a a symmetry and vertex of ● a F quadratic standard, Finding of function factorized quadratic and function in three vertex given on its What shape How do Finding a function to model a real-life Understanding an object in a how given many unique dimension of points dene the parameters aect How can you in the of of shape express three What are the a a of a quadratic quadratic its graph? quadratic dierent advantages disadvantages space ofa ● D ATL graph ways? parabola ● ● the C graph function ● is distinct ● points innovation questions function three technical function? ● dierent and MROF ● Inquiry function Expressing Scientic quadratic What than makes of the and dierent forms function? one quadratic form better another? Critical-thinking Apply existing knowledge to generate new ideas or processes 8.2 9.2 11.2 Statement of Inquiry: Representing systems, patterns models and with equivalent forms can lead to better methods. 3 21 Y ou ● should interpret already graphs of know linear 1 functions In how the do m to: linear and c function y = mx + represent? c, what y 5 2 From the graph, nd: 4 a the x-intercept 3 b the y-intercept 2 3 a Determine if the gradient 1 is b positive Find the or negative. equation 0 of x 1 1 this ● factorize a quadratic 4 line. Factorize: 2 expression a x b 2x + c x d 3 5x + 6 2 3x 2 2 49 2 Quadratic F You are ● What ● How do of graph? its shape surrounded the by 2x functions: is the graph parameters many of of dierent a a x standard quadratic quadratic shapes form function? function which can aect be the shape classied A according to their mathematical properties. One of the most common shapes trajectory the an arch. Arches can be seen everywhere, from the shape of a banana to ight as the from path Reect The you knew or How the many ball a just 32 2 discuss shows one the or the of ball bridges and buildings, and in trajectories, such 1 trajectory of a basketball. The trajectory is a the ball’s would go positions in the in the basket? air, could What if you you tell knew two of three? positions would question to parabola. not positions, fountains basketball. and called whether its a photograph curve, If water of go in do the you think basket? later. 9 Space you Make would a good need to guess. know You to will be sure return path of mouth moving guards, is is to that this object. a A LG E B R A Exploration 1 Tip 2 Graph the quadratic function y = x . The graph is a parabola. If your graphing program 1.1 has y a or slider function, insert a change in a the GDC bar you slider the can to values functions 2 0 f1(x) = easily. ax 1 10 10 x 0 1 2 1 Graph y = ax non-integer for a few values of a between 10 and +10. Include some values. 2 2 The parabola basketball’s in the graph trajectory is of y = concave x is concave down up . The parabola of the . Tip a Find the values of a for which the parabola is concave up. A b Find the values of a for which the parabola is concave parabola resemble c Find the values of a that make the parabola narrower can down. than the a smile or graph a frown; could this 2 of y = x help you remember 2 d Find the values of a that make the parabola wider than the graph of y = x 2 3 Graph some y = x + c for non-integer dierent values of c between 10 and +10. the for Include values which of the parabolawill values. a be concave down concave up? or 1.1 y c 0 5 5 1 2 f 2(x) = x + c x 0 1 Describe the eect of changing the value of c 2 4 Graph some y = ax + bx non-integer (Leave a = 1 for for dierent values. the values Describe the of b between eect of 10 and changing +10. the Include value of b. moment.) 1.1 y b 0 5 a 5 1 5 5 1 2 f 3(x) = a x + b x x 0 1 Continued on next page 9.2 A parable about parabolas 323 5 Graph the the graph Go back linear function changes for y = bx dierent for dierent values of values of b. Describe how b 2 6 xed to and dierent 7 Use the parabola change values your b. of y = ax Describe + bx. how Give the a any shape of value the except parabola 0. Keep changes a for b ndings to describe the similarities and dierences in the shape Try of the graphs of each pair of quadratic to these 2 a y = 2 2x + x + 1; y = 2 8x + x + answer functions. 1 b y = questions 2 3x 1; y = −3x without 1 graphs. 2 c y = 10x 2 ; d y = x drawing You e y = the use 2 + 3; y = x 1 technology 2 can to check 2 + x x 1; y = x of a x + 1 your answers. 2 The and A standard c are real parameter ● form numbers, of a of quadratic and function a linear a ≠ graph The parameter m function The graph quadratic The parameters denes its is y = ax + bx + c, where a, b 0. denes The function the y = form mx + gradient; of c its is the graph. always a parameter straight c line. denes its y-intercept. 2 ● concave The of up a or parameters a, b and concave a, b and c function c dene down, are y = ax + whether and called its the bx the + c is always parabola is a parabola. slim or wide, y-intercept. coecients of the quadratic function. 2 Parameter is called a, the Quadratic A coecient of x , is called the leading coecient. Parameter linear functions functions. integer These belong are to the functions family where of the functions variable x called has only exponents. polynomial is a mathematical expression involving a sumofpowers 4 one The A or more degree linear function c constant. and polynomial positive the variables of a polynomial function is a multiplied is a by function polynomial polynomial coecients, is the value function function of of degree forexample, of its degree largest 1. A of A constant 2 x 3x + exponent 1. of x. quadratic polynomial degree 0. example, 2. constant y = 2 y = 2x can has For the function be written 0 ATL Reect ● Why is What ● Why ● One for and the type do parameter of you ordered example: line, for How 324 such a function think pair (2, of points as the 2 in the would quadratic result parameter 7). example: many space, discuss c is coordinates Two (1, do 3) points and you graph 9 Space (5, think of a if a called denes dene function = a the a not allowed to equal constant? 0-dimensional 1-dimensional space, space, or or point, straight 2). are required quadratic 0? 0? to dene function? a 2-dimensional , 0 since x = 1. A LG E B R A A straight on the from the line has parabola positive to a has constant its own negative, gradient. gradient. or vice A The versa, is parabola point does where called the not. its In fact, gradient vertex or each point changes turning point of parabola. vertex negative positive negative positive gradient gradient gradient gradient vertex A concave maximum down parabola turning has a A concave minimum point. = ax parabola has a point. 2 2 y up turning + bx + c, a < y 0 = ax + bx + c, a > 0 maximum turning point minimum turning point ATL Exploration 2 2 Here is the graph of y = x 2x 3. y ( (3, 0) 1, 0) 0 x 2 y = x − 2x − 3 (1, 1 Describe the 2 State the equation 3 State the coordinates 4 Describe and the the symmetry of of the of of axis the relationship x-coordinate the parabola. of symmetry. vertex. between the 4) the equation of the axis of symmetry vertex. Continued on next page 9.2 A parable about parabolas 325 5 State the x-intercepts. x-intercepts x and x 1 vertex x . Determine of the the function relationship and the Graph step 5 this relationship y = The the as a formula: x = a ______. the following works for quadratic these functions. Test that your 4x function formula the points the graph All the Now 5 b quadratic test whose your y = functions formula leading 8 y = + 6x 7 c y = −x + 2x + 10 in from coecient a step step ≠ 6 5 have on leading the Copy coecient following a = quadratic 1 or 1. functions ±1. 2 2x + and 4x 1 b complete x-coordinate Quadratic of the this c table vertex function for with all the the parameters quadratic Parameters a 2x and a + 5x 3 and b functions b and in the steps 6 x-coordinate the vertex, and 7 of x v 2 y = x − 2x − 3 a = 1; b = −2 x = 1 v Find a pattern relating x to a and b. Write this relationship as a formula. v 9 10 Create your own quadratic functions, and test your formula in your examples. Explain how to nd the y-coordinate of the vertex, when you know its x-coordinate. 11 Factorize between Explain 12 the the Determine quadratic expressions x-intercepts why this how and the relationship to nd the in step factors of 6. Describe the the quadratic relationship expression. holds. y-intercept of any quadratic equation of the 2 form y = Reect ● What Is it Do do you main + c. discuss think for think would it 3 happens to it’s it still if have possible look characteristics ● x-intercepts ● axis ● vertex of you bx a quadratic function x-intercepts? If so, isn’t how factorizable? would you them? What The + and possible nd ● ax and like? of 32 6 9 Space for a quadratic When the y-intercepts symmetry where crosses the x-axis. are also They 2 x 2 a the of from zeros 7 are of graphs. 2 x x-intercepts x-coordinates v 2 a the of 2 Write v 6 between x-coordinate do graph you of a function think this quadratic to have would no x-intercepts? happen? function are: of called the the function A LG E B R A Properties of quadratic functions 2 For a quadratic function ● the x-coordinate ● the equation ● the coordinates ● the y-intercept For a quadratic of of its of is the f (x) (0, ax vertex axis its = of + bx c, a ≠ 0: is symmetry vertex + is are c) function f (x) with x-intercepts x and x 1 ● the x-coordinate of the vertex is ● the y-coordinate of the vertex is f (x : 2 ) v Practice For each 1 quadratic function in questions 1 to 6: Use i nd the coordinates of the your check ii nd the equation of its axis of only symmetry your after worked iii determine iv nd v if vi draw the the whether function is concave up or is sketch factorizable, of the nd quadratic the y = function using your y = x 5 y = −2x 6 2 y = −x 4x 2 + 4 y = −8x 6 y = 3x 2 20x 51 Write a concave 8 Write a quadratic can the from i to v 2x 4 + 16x 11 use up graphs modelled ball at 6x + 1 solving 7 hits results 2 + Problem be down 2 3 can have out. 2 x x 2 You concave you them x-intercepts 2 1 to results y-intercept function a the GDC vertex a as quadratic function of with quadratic parabolas. height of 1 function axis with of functions For x-intercepts symmetry to example, solve during x = 2 3. 4. real-world a and baseball problems match a that player m. 9.2 A parable about parabolas 327 The height h (meters) of the ball at time t (seconds) can be modelled by the 2 quadratic function maximum ball ● hits height the = the −5t ball + 14t + reaches, 1. You and can how graph many this function seconds it to takes nd the before the ground. Represent Time h time cannot on be a the x-axis, negative since value, so time t ≥ is 0. the At t independent = 0, the variable. height of the ball is 1 m. The time depend ● height, ≥ y height (1.4, 10.8) (m) 2 = − 5x + 14x + 0 x time hits How the the the graph ground could you function give the y two = you can again nd 8. see after the times: 0.65 the 2.87 times Using a 1 (2.87, 0) (0, 1) maximum height of (s) the ball is 10.8 m and it seconds. when GDC, seconds the the and ball’s points 2.2 height of is 8 m? intersection seconds, both Add of to the rounded your two to 1 graph graphs d.p. y height y = (1.4, 10.8) (m) 8 (2.2, 8) (0.65, 8) 2 y = − 5x + 14x 0 1 x time Practice + (s) 2 ATL Graph the functions reasonable Problem The the US to viewing these questions. When using a GDC, rst set window. solving Food number answer of and Drug bacteria Administration B in food uses refrigerated this at mathematical temperature T model for (°C): 2 B The temperature 2°C will and be at 32 8 14°C. a in a = 20T particular Determine minimum. 9 Space the − 20T + refrigerator temperature 120 can be where set the time is independent variable. y From so 0. the 1 not the Represent height on the y-axis, since height is the dependent variable. The ball will always be above the ground, or on the ground, so h a does on anywhere number between of bacteria up A LG E B R A 2 A boy time throws sees it a fall stone into into the the air while water.The standing height h (m) on of a the cli and stone at after any some time t (s) 2 can be modelled a the height b the time above it takes maximum c 3 the A time tennis by = the takes −4.8t sea height it ball h it + 16t + 45. level at which stone to reach Determine: the its stone was maximum thrown height, and the reaches the stone manufacturer to hit the estimates water. its daily costs using the function 2 C (t) of 200 tennis the 4 = 10t balls where 0.114t produced. minimum Sarah’s + C is Determine the the cost in dollars, number of and tennis t is balls the number that produce cost. banker tells her that the value of her investment can be modelled by 2 the function thousands 5 a the b how A v (t) of initial = 45 euros + after amount many company’s 75t it where months. that months weekly t 4t Sarah takes prot P v is the value of her investment in Determine: invested for Sarah’s from investment selling x items to can reach be maximum modelled value. using 2 the function company P (x) needs = to −0.48x sell Algebraic C ● How ● What of a can for 38x forms you are + the 295. maximum express a of a and the number of items the prot. quadratic quadratic advantages quadratic Determine weekly function in disadvantages function three of the dierent dierent ways? forms function? 2 The quadratic either of these function y functions = x x gives the 2 factorizes same to y = (x + 1)(x 2). Graphing parabola: y 6 5 4 3 2 2 y y = (x + 1)(x − = x − x 2 2) 1 0 4 3 2 1 x 1 2 3 4 1 2 3 The factorized form of a quadratic function is y = a(x p)(x q), a ≠ 0. 9.2 A parable about parabolas 32 9 Reect ● The and x-intercepts appropriate ● How do of the of a 4 function are also called its zeros. Why is this an name? you function Most discuss determine when it is quadratics in the coordinates factorized you have of the vertex of a quadratic form? considered so far have had two distinct 2 zeros. Now consider the quadratic function y = x + 2x + 1, which factorizes 2 toy = (x + 1)(x + 1) = (x + 1) and has graph: y 2 y = x + 2x + 1 6 5 4 3 2 1 0 5 4 3 2 x 1 1 2 2 The one function unique quadratic Using y x zero, also the = + x = work formula 2x −1. for + x has Does a only the one the ( −1) + unique formula quadratic nding x 1 function, 1 when x this + you function x-coordinate factor, (x developed has of only the + 1), for one vertex and the only vertex unique using of a factor? the zeros of ( −1) 2 = = = −1 v 2 2 b Using the formula x = 2 − = − = −1 v 2a Both formulae work Exploration 1 Graph these coordinates equal to for this the quadratic the functions vertex. Verify 2 y Write the 3 = (x Based down on of each a y b the = of the ndings function (x + (x + For each, state x-coordinate of the the vertex y between quadratic in below. c steps Verify 1 = −(x the 2 1) d x-coordinate y of b y = and your (x −(x the + 9 Space 1) vertex and function. 2, state answers the by coordinates graphing the 2 2) = 4) of the vertex functions. 2 c y = −(x + 4) Continued 3 3 0 is 2 3) relationship factor your y 2 = the 2 2) unique separately. that x-intercept. 2 a function. 3 quadratic of 2 (1) on next page A LG E B R A 4 In all 1. the quadratics Explore the the x-intercept coecients. in steps 1 relationship in the Write to quadratic down 3 the between your 5 y = The 2(x below with of was the b form of a y = either vertex dierent 1 or and leading ndings. 2 3) general coecient x-coordinate functions 2 a leading the −3(x quadratic + 2 2) c function with y = only −2(x one 2) unique 2 x-intercept and When the a the y at and, = a(x x-intercept quadratic x-axis factor is one h) in therefore, the a Write terms function point, . has of repeated to the y = (x function coordinates of the vertex the zero unique graph. at this solution, The its function graph has a intercepts repeated point. 2 and 2) one of 2 Graphing the h only vertex down y translates = (x the 2) + graph 4 4 on units the in same the axes shows positive y that adding direction. 4 The 2 graph of y = (x 2) + 4 has vertex (2, 4) and no x-intercepts. y 2 y = (x − 2) + 4 (2, 4) 2 y = (x − 2) 0 x (2, 0) 2 Graphing y subtracting = 3 (x 2) from 2 and the y = (x 2) function 3 on translates the the same graph 3 axes shows units in the that negative 2 y direction. The graph of y = (x 2) 3 has vertex (2, 3) and two x-intercepts. y 2 y = (x − 2) 2 y = (x − 2) − 3 (2, 0) 0 x (2, 3) 2 The quadratic vertex functions y = (x 2) 2 + 4 and y = (x 2) 3 are written in form. 2 The (h, vertex k) is the form of a quadratic function is y = a (x h) + k, a ≠ 0, where vertex. 9.2 A parable about parabolas 3 31 Practice For 1 to 6, determine 3 state if the the coordinates quadratic is of the concave vertex up or of each concave quadratic y = (x 3 y = 2(x 5 y = −x 2 3) + 1 2 y = −(x 4) 4 y = −3(x 6 y = 3x 3 2 + 1) + 2 2 1 2 A the Conver ting To 2) + 1 convert 1 solving quadratic Write + 2 Problem 7 and down. 2 1 function function function quadratic from with in leading vertex coecient 2 has a repeated zero at x = form. forms factorized form to standard form, expand the brackets: 2 y If = you form (x can to + 3)(x 2) factorize factorized → a y = x + quadratic x 6 function, you can convert it from standard form: 2 y To = x x convert 2 from → y vertex = (x + form 1)(x to 2) standard form, expand and simplify: 2 y + = (x 1) = (x 1)(x = x = x 2 1) + 2 2 2x + 1 + 2 2 ⇒ y How do 2x you Exploration + 3 convert will Exploration 1 Expand from help these you standard answer form this (x + (x b (x at e your relationships 3 For these into two linear results in between quadratic identical factor. (x step p + c x c x f Write In b, functions, factors (x down + 1) + the (x and + + x + p values p), 2) 2 = between choose p)(x p) (x in bx of other factorization + and for c c, nd the c so that words: each they the factorize square of a one. 2 4x + c b x d x 2 4 (x 2 3) 1. and 2 a next 2 3) 2 1) Look (The 2 2) 2 2 form? expressions: 2 d vertex 4 2 a to question.) + 4x + c 2 + Write x a + c general rule for what x + c you did in step 3. For a quadratic function 2 x + bx linear 3 32 + c, express c in factor. 9 Space terms of b for the quadratic to be the square of a 3. A LG E B R A In steps rst 3 two and 4 terms of of Exploration a quadratic 4 you were expression, completing you found c the so square. that the Given the quadratic 2 factorizes into coecient You can of use standard the the square x Example to a linear factor. For this, c b = , 2 where b is the term. completing form of vertex the square to convert a quadratic function from form. 1 2 Write y = x + 2x 2 in vertex form. 2 y = x + bx + c 2 = = 2 1 = 1 2 x Use to complete the square for the x and x terms. 2 + 2x + 1 = (x + 1) Write the completed square in the right hand 2 y = x + 2x 2 side. As this adds 1, subtract 1 at the end. 2 = (x = (x + 2x + 1) 2 1 2 y + 1) You could check and simplifying. by expanding 3 Example 2 2 Sketch the Vertex is ( graph 1, of y = (x + 1) 3. 3) 2 For Axis of symmetry 2 y = (x + 1) is x = y = h) + k the vertex is (h, k). −1 2 – 3 = = −2 x + 2x 2 In y-intercept a(x standard form, y-intercept = c 2 Graph is concave up. Positive Find 2 When x = 1, y = 3 2 = some other points coecient on the of curve x . by 1 substituting a few values for x 2 When x = −3, y = ( 2) 3 = 1 y Connect 0 x a the smooth points parabolic with curve. 2 ( 1, 3) 9.2 A parable about parabolas 3 3 3 Reect Consider and the discuss two equivalent 5 quadratic functions: 2 y ● = 2 x + 2x Which 2 form information ● In is ● How the use the What many Practice The 2, standard is form quadratic in y = function sketching y-intercept another and its of + gives 1) 3 you in vertex more form. immediate graph? was way (x found by nding expanding the the y-intercept? original Which way easier? function 1 of to Example function. in points or draw are its necessary graph? to determine a unique quadratic Explain. 4 quadratic functions below are given in standard form. Tip i Convert ii Sketch each function into vertex form. Find the graph of the quadratic by using the vertex and two and points on the y = 2 + x 2x + 1 b y = y = −x g y = x + 1 e y = x h y = x 2 2 For the 4x x + 2 quadratics nd the ii nd two iii sketch = vertex other the 1 Match using the points of on the formula y = the y = f y = i y = + 6x + x + −x quadratic 3 1 2x + x value nd third 1 3x a 2 1 x the x-coordinate of the vertex using the points you have found. 2 x b quadratic 1) y = 2 2x 4x + 1 c y = 1 c y = (x 6x 3x function with its graph. 2 3 b y = x 2 + 2 2) 2 + ‘easy’ quadratic 2 d 3 solving each (x + x for 2 a = below: graph 4x Problem 3 y 2 2x 2 y c 2 + i a 2 2 6x 2 e y = x + 1 2 3x 1 f y = 2 x x y y y 3 2 2 1 1 1 x 0 2 1 1 2 3 4 0 5 4 1 3 2 1 3 2 1 x 1 2 3 4 2 1 2 3 2 3 4 3 4 9 Space x 1 1 0 3 34 an of x to 2 x 2 d y-intercept, substitute quadratic. 2 a the other 2 point. A LG E B R A y y 3 1 y 5 5 4 4 3 3 2 0 4 3 2 x 1 1 1 1 2 0 4 3 2 Reect and discuss a quadratic function that ● Find a quadratic function whose ● Find a quadratic function ● 1, Compare 2 0 3 2 x 1 1 2 3 4 5 1 6 Find ( 1 1 ● zeros x 1 3 with goes through zeros vertex are (1, x 2) the point = and 0 and one (0, x = of 1). 4. its 3). your answers with others. Did you all nd the same functions? Explain. Solving To solve from to real-life real-life the use given to a b a have Find = 2(l + the and may then have to decide derive on the the quadratic best form of function the quadratic question. meters plot’s Determine P you 3 100 the problems, information, answer Example You problems w) the = of fencing maximum enclose possible dimensions 100 to a rectangular plot. area. dimensions give the maximum area. [1] Write A = lw From 2(l + and [2] equations area of a for w) + = 100 w = 50 l = 50 = (50 l in terms of w)w = 50w Substitute by the into [2], to get w equation linking A and w 2 Area a is given maximum w w 2 A perimeter [1]: Write l the rectangle. value quadratic at its function 50w w , which has vertex. Continued on next page 9.2 A parable about parabolas 3 3 5 an Method 1–nding the vertex using the factorized form 2 50w w = w 0, = w = w(50 – w) = 0 Find the zeros of the function. 50 A maximum Sketch and the graph identify its of the function maximum point. The maximum area of the 0 w 25 rectangular plot occurs when w = 25. When A = w = 25: 25(50 25) = 625 Calculate the maximum area. 2 Maximum Method area = 625 2–nding m the vertex using the standard form 2 A = w (50 w) = 50w w Find When A = w = the x-coordinate of the vertex. 25: 25(50 25) = 625 area = 625 2 Maximum Method 3–nding 2 m the vertex using vertex form 2 w 50w = (w 25) 2 625 Complete 2 Hence A Vertex = = + −(w (25, 2 50w) = −(w 25) + 625 625) 2 Maximum b When w = maximum Reect When and area 25, l area and sketching = 625 = 50 are standard ● factorized ● vertex 3 3 6 w = width graphs of of: form form form? 9 Space 25. = discuss disadvantages ● m The length dimensions = 25 m (a that produce the square). 7 quadratic functions, what are the advantages the square for w 50w. A LG E B R A Practice In these use the 5 questions, most Problem 1 You side have of a derive ecient the quadratic method for function answering the that best ts the situation and question. solving 300 m river, of as fencing to enclose a rectangular plot along the shown. River Plot Determine of 2 the You the have a rectangular 3 total of plots. enclosed is Xixi wants fence as possible The that use to one exercise and a would these square as side perimeter sides area of 200 m of that you fencing Determine area house 4 maximum can enclose and the dimensions plot. big as o of a the the to make dimensions two of equal, each adjacent, plot, such that the total possible. rectangular area. She exercise has 10 m area of for her fencing. dog, Find using the the maximum area. an athletics semicircle at maximize dimensions the to track each end. area nd of the is 0.4 km. The Determine the rectangular area of the track the exact part entire of track has two values the parallel of track eld to x and eld, the r and nearest meter. X r Form D ● Given a What quadratic y-intercepts quadratic and and makes function one equation, vertex. If quadratic you you can start form sketch with a better its than graph parabola, by another? nding how can its you x- and nd its function? 9.2 A parable about parabolas 3 37 This photograph Consider The the x-intercepts enough of water parabolic and information fountain fountains shape of the y-intercept, to nd the is superimposed 2nd which fountain is quadratic also upon stream the vertex, function coordinate from are modelling axes. left. labelled. the Is this parabolic stream? Tip Some and GDCs graphing software have functionality the of superimposing picture on coordinate 2 The general form Substituting the of a quadratic coordinates 2 y = a(x How the ( + you parabola 4.4, 0) or the vertex with (0, vertex 7) for h is (h, k) is y = a(x and k gives have a negative h) 7 or nd is y = the ax × 4.4 + 7 0). coecient down. You Substituting can the x- a? use and It must one of the y-values at two other point (4.4, value points 0) since given: gives = 0. Solving for a gives: 7 a = = −0.361 (3 d.p.) 2 4.4 2 The You quadratic can function graph 3 3 8 k 7. leading concave (4.4, + 2 a + 2 0) can of function this that models quadratic 9 Space on the the fountain same stream coordinate is axes y = to −0.361x check: + 7. a a pair axes. of A LG E B R A ATL Reect ● and Again, nd stream, but coecient ● Does is ● the this a. your an What a ● it discuss Is minimum When nding standard ii vertex iii factorized and basket? A point in space A line one A curve Can has has you object in two a to models nd the the fountain leading function exactly model the parabolic fountain, or Explain. do you need to determine the equation of equation you of a quadratic function, under what use: form to form? 1 asked: know to answer has no How be is how many sure and many space? that positions the ball do you would think go into the ‘three’. dimension, dimensions three-dimensional an that function? dimension guess quadratic x-intercept function? model? would correct it. same the other information the discuss determine of the form need The the quadratic i would it form use quadratic circumstances you time approximate unique Reect general 8 and needs and four-dimensional two needs points How needs points three determine many one points a to point to determine points to unique would it. determine object you it. in need to uniquely dene universe? You 3D a Exploration 5 2D as can project objects onto space, with such television transmission. The Golden spanning The Gate the diagram Bridge channel shows in San between the Francisco, San central USA Francisco section of the is Bay a suspension and bridge. the The Pacic the same a way, 4D objects Ocean. suspension can be cable projected is In bridge onto a parabola. 3D space. y x Continued on next page 9.2 A parable about parabolas 3 3 9 1 Research 2 Trace the 3 for 4 the axis Use the the Using the heights parabola. of and your y the Draw symmetry dimensions x of of towers a the you pair and of the length coordinate of axes, the central with the y section. axis as parabola. found from step 1 to determine a suitable scale axes. scale, nd the coordinates of the vertex, and the x- and y-intercepts. 5 Using your parameter 6 Compare Practice 1 Trace Find your function and another point on the curve, nd the model with others. Discuss any similarities and dierences. 6 each a quadratic a parabola. quadratic Draw function coordinate to model the axes and decide on a suitable scale. parabola. a b c d Exploration Take photos technology tracing paper Reect Why of to 34 0 parabolic it objects nd the quadratic over the photo. and might 6 be discuss that so encounter that in your denes everyday your life. object, or Use use 9 many 9 Space you function natural and built structures are parabolic? A LG E B R A Objective: v. Justify real-life In this will Applying whether a mathematics solution makes in real-life sense in the contexts context of the authentic situation. activity then your D. you decide will which write one is quadratic better in models that describing the describe given the given scenarios, situation. and You explain choice. Massachusetts Activity physical For a free throw shot in basketball (in US standard teacher ● ● ● education units): James Naismith the the the free throw basket is player line 10 ft is 15 ft above releases the away the ball from the foot of the basketball in the late to keep ground from an approximate height of 8 his ft 1800s class indoors occupied in weather. peach ball 1 Find two Make 2 Decide for 3 life 4 5 the your the ball, of these intercept the the not might can ball that could satises quadratic reasons select the model the your one shot into the basket like a used and soccer that that choice you is most of basket. appropriate form. think best models a take the into account shot goes real- the factors basket. that aect Suggest the what path some be. opposing that jump in some into an to your reaching team could opposing reach a model? the intercept player maximum If so, is of modify 5 the ft 10 ball away ft. your on its from Could the this function way so to free player that it basket. 9.2 A parable about parabolas a a ball. specications. function for the bad He why. the ball the give models, Assume and of whether from basket. thrower function and does factors player models form two or functions each Explain model of the that models, shot. Your A on your From dierent sure invented basket 341 Summary ● The standard form of a quadratic function is ● A concave up parabola has a 2 y = ax + bx + c where a, b and c are real minimum turning point. 2 numbers, and a ≠ 0. y = ax + bx + c, a > 0 minimum turning ● The y ● = factorized a(x The form p)(x vertex q), form a of of ≠ a a quadratic function point is 2 0. ● quadratic function For is a quadratic function the x-coordinate the equation of f (x) the = ax vertex + bx + c, a ≠ 0: is ° 2 y = a(x h) + k, a ≠ 0, where (h, k) is the vertex. of its axis of symmetry ° ● The degree of a polynomial function is the is value of its function A of ● A is largest a quadratic degree turning polynomial function 2. concave exponent A is down x. A function a constant of linear of degree polynomial function parabola has a has 1. the coordinates the y-intercept of its vertex are ° function degree 0. is c ° maximum ● point. For a quadratic function f (x) with x-intercepts 2 y = ax + bx + c, a < x 0 and x 1 : 2 the x-coordinate of the vertex is x ° v maximum turning point the y-coordinate of the vertex is ° Mixed 1 For practice each quadratic function: a Express terms i nd the ii state vertex, x-intercepts and y-intercept and whether b the axis of symmetry, it up or concave sketch a y the total Find x 12 b y = x + 7x + = x 3 d y = 2 x These −6x Soraya 5x 1 f y = 2x 9x each the maximum has 40 functions are in standard one to vertex form, and of the c y = x + 6 b y = x The x 2x Kanye fencing Find to make the a dimensions + has state by P of the the an animal species function 2 = −0.38t time in + 134t months + 1100, since where the t is population 9 d y = x + 6x + 8 2x + 7 observed. was x 5 f y = x x + the 7 at number its of months until the population maximum b the maximum population c the number months solving 600 m of fencing to make of before the species ve pens like this: 6 A 5 ball m the x It is lands 9 Space and the on the this vertex up into ground. reaches thrown. models y thrown above ball was 34 2 rst Determine: disappears. adjacent for area. 2 Problem 3 play population modelled a = of area. 2 + 2 y area. 2 4x 2 e maximize vertex. 2 x will form. the = m play maximum P (t) coordinates y that 5 is a x 2 + quadratic Change of 3x 5 2 value 2 2x 2 y the 12 the e in 2 + x 2 = pens area. rectangular y the graph. 4 c of down 2 = area x Determine c iii of total is the concave the a a 5 2 from seconds, height seconds quadratic situation. form. air, After maximum ground Find the Write it of 9 after it function in m. that standard is A LG E B R A Review in Scientic context and technical innovation d The area of is of , the a region where parabola, distance from b formed is and its the h is vertex by a length its to parabola of the height, the a base i.e., Because truck enough the fully. base. and of 1 This rollercoaster is in Münich, Germany. e and that of the outline of of foreground the parabolic truck section of Draw axes and use the c Find a d Use this 2 At a If the is with center 0.2 m can width in the line. 0.8 open m to of open 2.6 right The below opens door a stuck need door the to top top the fully, of map the function to of of to is the Hill the same in to determine model estimate tunnel maximum as entrance Budapest, side. steps. how close be in passenger to d the be side and of still the be tunnel able its determine maximum a of the that the width, quadratic Describe some architects issues/concerns take into that account you when a a tunnel before its construction. the shape of area under runs through tunnel 9.8 model to is the meters, represent thetunnel. b State a geometric represent c If a a typical determine be put travel on truck truck the show through all of and How you have a that the width if of they tunnel you steps could through limitation trucks that the Reect has height these assumptions model passing in your be the 2.62 that are safely. made and to m, should going State be used tunnel. to any sure to solution. discuss explored the statement of inquiry? Give specic examples. Statement of Inquiry: Representing models and patterns with to door. Hungary. height the showing track. function m lane section. right Castle is meters, would passenger truck m 350 tunnel scale. suitable section the door the could modelling suitable the almost the track. think b the by is section f the your a 3.4 door Determine open Trace tunnel driver’s Show the a of in for Suppose truck, all length room height the the its stopped equivalent forms can lead to better systems, methods. 9.2 A parable about parabolas 34 3 10 Change A variation in size, amount or behavior Changing One strategy problems can’t you is solve can the for to solving change into problem Changing mathematics them equivalent from ones problems you a that fractions, changes the decimals way you solve. example, fractions you with cannot different 3 directly can you calculations add denominators, say: out change to make the numbers them easier in to mentally? 2 7 you can equivalent change form 5 this which 15 Changing A formula calculate speed ● = the a b c distance else = = can calculate the speed 34 4 of a car or 50km, 426 + 99 65% of 20 solve: 50km, s by = substituting d/t time time time when and/or between when: 80km, = = = 2 2 4 hours hours hours. you change time? change distance, and 24 subject speed you to × 35 relationship changes distance How to = distance What ● the distance the the distance/time Calculate possible 0.75 an 29 35 speed into = the shows is 14 + 35 addition time? the formula given quantities. values into You the can formula: 14 ÷ these work + But and express number. How For between percentages 0.07 Evolutionary The theory over time. presented voyage In adapted On the He to now the suited reproduce. to Individuals that a that had are collected these pass genes a in the most their are less likely have of individuals to to but selection. genes likely genes and origins environment, are Darwin ve-year natural in change plants common through any on Charles during differences In species variation have environment then living (1859), studying species. will that Species species there without in he how environments that They of world, claimed within describes Origin evidence know reproduce the different individuals most evolution around animals. We of change survive their survive and offspring. and environment. A girae can with reach giraes a food longer that neck other cannot. A The girae’s girae than inherit the long Climate ice changed periods, in the debate – rate than is Scientists help us of know years, exact all causes that from global that between 10 000 agree atmosphere food other to giraes sur vive is and more reproduce. the ice years of ages and amount burning fossil temperatures at warmer them. interglacial of carbon fuels a climatehas with between glacial the Earth’s – present oil, coal faster before. analyze How to we about increasing ever change. of the almost Earth’s gas data millions periods but and ● sample over Scientists more change core interglacial gets neck. likely From that ospring can make data to observe predicting and change predict also changes? 34 5 A frog into a prince 10.1 Global context: Objectives ● Understanding Orientation Inquiry how various parameters ● aect in space and time questions What transformations can be applied to F the ● shape Applying and position translations, of a graph reections lines and MROF ● What are linear and Describing the transformation of a and Describing combinations of transformations How algebraically and graphically the can If equation of a graph following the graph use of transformations a graph? to nd of a transformed function the same as the graph of the original one function, more you equation D is or for graphs? of ● function Writing transformations graphically the ● three quadratic function ● a the C graphs algebraically ● curves? dilations ● to and has the function been transformations transformed? ● If two graph are ATL dierent of the the transformations same transformed transformations really give the function, dierent? Creative -thinking Generating novel ideas and considering new perspectives 10.1 14.1 Statement of Inquiry: Relationships patterns of that can help and predict frequency 34 6 model change clarify duration, and variability. A LG E B R A Y ou ● should sketch already graphs of linear know and how 1 to: Sketch a graph of : 2 quadratic ● write functions quadratic functions in a f(x) a Write 2 = 2x + the 3 b quadratic f(x) = x function 2 ver tex form y b = x + Write 6x + 8 down in the ver tex form. coordinates of the 2 ver tex Changing F ● What Changing the the the graph of y = x + 6x + 8. graphs transformations parameters coordinate of of a can line or be applied quadratic to lines curve and changes curves? its position on plane. For a straight line For a quadratic y = mx + c, the y = (x parameters are gradient m and y-intercept c. 2 function, Exploration 1 Use your given must be In y = y = and x-values the to to draw the parameters match y of = 3 x to 13x following briey the are h and k x-values 54x of 2 2x 2x pairs how of curves the on the rst curve have used curve. 1. 3 and y-values 72 and y and y-values to words 3 + of 3 + in second 2 x Use k, describe 4 2x 3 b case, 3 x Use software each transformed 4 a + 1 graphing axes. h) 8 = 3 to 5. 2 x 4x + 3x of 4 of 20 of 1 + to 2. 4. 2 c y = x + x 6 Use x-values Use x-values and of y = 3(x + 3)(x 4 to 3 and 4 to 4 and and d 2). y-values y = y-values and x-values of x 0 to 4 f 2 When x-values words terminology Research three of describing everyday 4. and . y-values of 6 to and Use to 2 x Use 6. . of 2 e to the have to 10 the like to . 10 and y-values transformations ‘shift’ make sure meanings of 6. and your the non-mathematical in step ‘stretch’. It meaning words of is is 6 1, 6. you might important fully reection, meanings to to use the correct understood. dilation as well as from step 1 and specic translation. All mathematical meanings. 3 Describe each reection, of the dilation transformations or using one of the terms translation. 10.1 A frog into a prince 34 7 In this the section, reections will A be measured translation amount A in factor. to by Practice curve but or when it or all is same these either three the types x-axis or of the transformation. y-axis. The All dilations y-axis. every point on a graph moves by the same a x-values dilated scale points on compression. the parallel a graph increased to the undergoes by y-axis, the all dilation same the scale y-values are factor. on the If are one other side side of of a mirror the line mirror to points the same line. 1 diagrams describe if x- only in direction. stretch maps away the x-axis, the reection distance These same a encounter reections from Similarly, increased 1 is the will be occurs the dilation parallel A you will the into show single the examples of transformation blue graph that transformations. has taken place to In each case, transform the red curve. y a 4 3 2 1 0 3 2 1 x 1 2 3 4 5 6 1 2 3 4 y b 4 3 2 x 0 9 8 7 6 5 4 2 1 1 2 3 4 5 6 7 8 9 1 2 3 4 c d y y 7 4 6 3 5 2 4 1 3 0 3 2 x 1 2 1 1 2 3 0 5 4 3 2 1 2 34 8 10 Change x 1 1 4 2 3 4 5 A LG E B R A e y 8 6 4 2 0 4 4.5 3.5 3 2.5 2 1.5 1 0.5 x 0.5 1 1.5 2 2.5 3 3.5 4 4.5 2 4 6 8 y f 6 5 4 3 2 1 0 4 3 2 x 1 1 2 3 4 5 1 2 3 2 These case, the diagrams identify blue show the two further examples transformations of graph which transformations. transform the red In curve each into curve. y y 2 4 3 2 0 4 3 2 1 x 1 2 3 4 1 1 2 0 4 3 2 1 x 1 3 1 4 2 5 3 2 3 4 5 4 y y 5 6 4 5 3 4 2 3 1 2 1 0 6 5 4 3 2 1 x 1 2 3 4 5 6 7 1 0 4 2 3 2 x 1 1 2 10.1 A frog into a prince 34 9 Problem solving 2 3 Use your Ronnie Reggie GDC says says Decide what Reect the Using y = + Predict Check Do y will also f (x dierent of How more exploration, aects as sense. If the y k x = are where f (x) of of 2 2) and the the y = (x + 2) other. other. correct. f (x) of y = = 1, f (x 4x predict + calculator. + 4 1) what will What represent the + quadratic transforming as the graph of look do like. you same notice? transformation or are as it does not, Once it equation aect its graph? is a to make you good observed you idea you with observations have Then perhaps consistent should to need ask to try about the how pattern, check a ndings your friend if rule they rephrasing varying you a should by try testing think your a to few rule it. 2 linear on r ules asked possible. Sometimes an transformations patter ns general graph. precisely Graph = (x translation reection Exploration graph y you the Exploration 1 f (x) Investigating examples. makes = like. does patter ns it = and B. describe describe a a y 1 graphical ii. this claims to the Objective: parameter is is of transformations? ● In y and Linear C graphs notice. look your 1) graph discuss what + the graph their answers using = one you graph 4 draw one and your f (x) that that whether Explain Draw to functions your graphing y = x and 1.1 software, y and insert of between k Try a slider dierent 10 to change and values of 10. k the Start to value with explore k y = = x 0. how y = x + k (1, 1) changing y = x to y = x + k values graph. k 2 Repeat step functions: and y = 3x Describe y = f (x) y + + 1 for = 2x k, y more = −x linear + 0 10 changing changes the y = f (x) to graph. Continued 3 5 0 10 k k how k three + 10 Change dierent x 0 the Try changes on next page of k A LG E B R A 3 Graph to Try y 4 the change = dierent 4(x h) Repeat y = y = h values of h changes 3 for + 3, 3(x Describe y of h) = = to the three y y = 4x and between 10 explore y = 4(x and how h). +10. Insert Start changing y a with = 4x slider h = 0. to graph. more (x linear h) functions: 1.1 2 y h) how f (x functions value step 2(x and to linear the h) changing changes y = the f (x) graph. 2 y 2 5 Graph the quadratic functions y = x = x and 2 y = (x − h) + k 2 y = (x h) + k on your graphing software, 0 and insert two sliders of and between to change the values h h k 10 and 10. x Start 0 k 0 with 10 10 10 10 2 h 6 = k = Find 0, the so y = x values . of h and k and write the equation the left of the parabola 2 y = (x + h) k that is: 2 a 4 units higher b 4 units to c both a Explain than y = x 2 the left of y = x 2 7 its b 4 units Vertical how and 4 units to of y = x changing the function y = f (x) to y = f (x changing the function y = f (x) to y = f (x) h) changes graph. Explain its higher how + k changes graph. and horizontal shifts in the graph of a function are called translations ● ● ● y = f (x translates y = f (x) by h units in the When h > 0, the graph moves in the positive When h < 0, the graph moves in the negative y = f (x) + k translates y = f (x) by k units in > 0, the graph moves in the positive When k < 0, the graph moves in the negative = f (x Reect When the h > h) in + the and 0, right k y = f (x) by h units to right. the left. y-direction. y-direction, y-direction, in the the up. down. x-direction and y-direction. discuss why and translates to x-direction, the k y x-direction. x-direction, When kunits to h) does not to y = the 2 f (x h) translate the function y = f (x) by h units left? 10.1 A frog into a prince 3 51 Example The red, The red 1 green and blue lines are y parallel. y Find in line the terms has equation equation of of the y = f (x). other = f(x) 7 lines 6 f (x). 5 3 2 1 0 4 3 2 1 x 1 2 3 4 1 The in blue the line is a translation of the red line by 4 units y-direction. y 7 6 Find that points on the correspond two to graphs each other. 3 2 1 0 4 3 2 1 x 1 2 3 4 1 Hence The the green right by 3 blue line line is a has equation translation of y = the f (x) blue + 4. line to the units. y 7 6 3 2 1 It is easiest between 0 4 3 2 nd blue corresponding and green points lines. x 1 1 to the 2 3 4 1 Horizontal Hence the green line has equation y = f (x − 3) + are 3 5 2 10 Change translations 4. of the form f (x h). A LG E B R A Example The red Find 2 curve the is a equation translation of the red of the curve blue in curve, terms of which has equation y = f (x). f (x). y y = f(x) 4 3 2 1 0 4 3 x 1 1 2 3 4 1 2 3 4 The vertex This 3 is units The a In moved translation of from 2 ( units 1, 1) to the to (1, right 4). Find corresponding points. and Identify the translation. down. blue curve Practice 1 has each graphs has equation y = f (x 2) 3. 2 graph are you are given translations of the that equation function. of one Find of the the functions. equation of y y = The each other function. y −3x 3 A C B 4 2 y = 0.5 x + 2 3 1 2 x 0 7 6 5 4 3 2 1 1 3 5 1 D 2 0 3 2 x 1 1 3 E 2 F 4 3 4 10.1 A frog into a prince 3 53 y y 7 2 2 G y = H x 6 1 2 y = −0.5 x 5 J 0 10 9 8 7 6 5 4 3 2 1 4 x 1 2 3 1 3 2 2 3 1 4 L 5 0 4 3 2 x 1 1 2 3 4 5 6 7 8 9 10 1 6 K M 2 7 3 4 Problem 2 Without solving using coordinates Label any of graphing points, intercepts software sketch with the the or a calculator graphs of or these nding any specic functions. axes. Start with y = x or 2 a y = x + 5 b y = 2x 3 c y = −2x y 3 = the 2 d y = 2 x + 5 e Exploration 1 Use graphing y = (x + 2 2) f y = (x 1) 1 3 software to graph the linear function f (x) = mx + c and 1 insert with a f slider (x) = x, to change with m = the 1 values and c = of m and c between 10 and 10. Start 0. 1 2 Add the graphs of y = (x) −f and y = 1 3 Change using the the values slider. relationship of m and the ( x). 1 Describe between f c 1.1 y the graphs f (x) = m x + c 1 y = f (x) and y = −f 1 y = Identify the 1 transformation of (x). f (x) to y that = −f 1 takes the graph (x). 1 f 4 Continue of m and to c vary using the the values slider. (x) 3 your graphs, of y = f (x) to that the takes graph of 1 ( x ) 1 0 describe the y = 0 c 10 −10 10 graph f ( x). 1 f (x) 2 = −f (x 10 Change ) 1 Continued 3 5 4 x 0 the 10 transformation f By m examining = on next page x and graph. translate 4 A LG E B R A 2 5 On a clear screen, graph the quadratic function y = f (x) = (x h) + k. 1 Insert 6 Add sliders the to graphs change y = −f the (x) values and y = f 1 in steps 3 and 4, nd of ( h and x). By k between changing 10 the and sliders 10. as you did 1 the relationship between the graph of y = f (x) and 1 the graphs of y = − f (x) and y = f 1 7 Explain for whether quadratic ( x). 1 the generalizations you made in steps 3 and 4 hold true functions. The graph of y = −f (x) is a reection of the graph of y = f (x) in the x-axis. The graph of y = f ( is a reection of the graph of y = f (x) in the y-axis. Example 3 Here is the graph x) of y 2 y = (x 2) + 3. 8 A Find of the 6 equations graphs A and B 4 2 y = (x − 2) + 3 2 0 6 5 4 3 2 1 x 1 2 3 4 5 6 2 4 6 B 8 2 Graph A is a reection of y = (x 2) + 3 in the y-axis. 2 Equation of A = f ( x) = ( x 2) + = ( x 2)( = (x = (x Reection of f(x) in the y-axis is f( 3 x 2) + 3 Substitute x). x into f(x). 2 + 4x + 4) + 3 2 + + 2) 3 Expand, then write in vertex form. 2 Graph B is a reection of y = (x 2) + 3 in the x-axis. Reection of f(x) in the x-axis is 2 Equation of Practice B = −f (x) = −(x 2) 3 3 y 1 Copy this Sketch sketch and label graph the of f (x) graph of = f ( 3x x) + 2. on the 3 same 2 axes. f (x) = 3x + 2 1 Sketch and label the graph of f (x) on the same axes. x 0 Label any intercepts with the y-axis. —2 —1 1 3 10.1 A frog into a prince 3 5 5 f(x). 2 2 Copy this sketch graph of f (x) = x 6x + 10. y 2 f (x) Sketch the and same label the graph of f ( x) = x − 6x + 10 10 on 8 axes. 6 Sketch and label the graph of f (x) 4 on the same axes. 2 0 x 1 3 In each other graph graphs below are you are reections given of that the equation function. y a of Find one the of 2 the 4 5 functions. equation b 3 of each 6 The function. y 4 4 L 3 L 3 1 3 L 2 2 1 1 0 x 3 2 1 2 1 3 4 4 2 x 1 5 1 1 L y = − x − 4 1 2 2 y = − 4 x − 4 3 3 y 3 3 2 2 L 7 L 5 1 1 2 y = (x 3) + 1 0 5 4 3 2 x 1 1 2 3 4 x 0 5 6 5 4 3 2 1 1 1 2 2 2 L L 6 y = −(x 3) + 2 8 3 4 The the graph of y y-direction y-axis Find to the give 3 = x + and line 1 is then translated reected y in in the 4 y L equation of line = x + 1 L 1 0 x L 2 5 The graph x-axis to of give y = x curve is translated C. Find the in the x-direction equation of curve and then reected in the C y 2 y = x 0 x 2 C 3 5 6 10 Change A LG E B R A Exploration 1 Draw Plot (1, a coordinate these 1), This A points: (4, set smooth 2 4 1) of ( and eight plane 4, (5, with 5), axes ( 3, from 2), ( 10 2, to 0), +10. ( 1, 1), (0, 0), 3). points denes the function f (x). Join the points with a curve. change is applied to f (x) to give a new function g (x). This change is 1 dened as g (x) = 2f (x). 1 a Write down the coordinates of the eight points of g (x). 1 b Draw and label the graph of g (x) on the same coordinate plane as f (x). 1 c Describe the change between f (x) and g (x). 1 3 Repeat step 2 for a new change g (x) = f (x). 2 4 Make a generalization changes a 5 when Draw is to g(x) 0 the < a = af (x): < 1 graph applied to of f (x) for what happens b f (x) to again give a on new a when when new a > the h (x). f (x) 1. coordinate function function plane. This A change change is 1 dened as h (x) = f (2x). 1 a Write down the coordinates of the eight points of h (x), for example 1 the b point Draw ( and 4, 5) label will the become graph of h ( 2, (x) 5). on the same coordinate plane as f (x). 1 c Describe the change between f (x) and h (x). 1 6 Repeat step 5 for a new change h (x) = f 2 7 Make a changes a 8 generalization to when Use 0 < graphing quadratic a h(x) Graph a = < for what happens 1 b software to see if when a = the insert 1 the function f (x) your a > 1. generalizations apply to linear and functions. linear functions f (x) = 1 and when f (ax): and a slider then to change explore what x, f (x) = a × 2 the happens f (x) and 1 value of a when 0 < f (x) = 3 between a < = x 0 1 and f (a × x) 1 and 3. Start when a with > 1. 2 b Repeat step 8a for the quadratic function f (x) . 1 10.1 A frog into a prince 3 57 The mathematical y = a f y = f term for (x) is a vertical (ax) is a horizontal stretch dilation of or f dilation compression (x), of f scale (x), is factor scale dilation. a, parallel factor , to the parallel to y-axis. the x-axis. af (x) f (ax) y y C C C 2 C 2 1 1 2 C f (x) = x f (x) = (4x) 1 2 a > 1 C f (x) = x f (x) = 4x a 1 > 2 1 C 2 2 C 2 0 0 x x 1 vertical dilation scale factor 4 horizontal dilation scale factor 4 y y C C 1 1 2 C f (x) = x 1 2 C f (x) = x 2 1 1 C C f (x) 2 2 4 0 < a < 1 C 2 1 C 0 < a < f (x) = 2 x 2 1 4 0 0 x x 1 vertical dilation scale factor horizontal 4 3 5 8 10 Change dilation scale factor 4 A LG E B R A Example 4 2 Here is the Describe graph the eect transformation, of how of of = and y x the giving individual transformed, y examples points sketch are the graphs of 2 a b 2f f y (x) = x (2x). 0 a The (0, graph 0) → of (0, 2f (x) is a dilation, scale factor 2, x parallel to the y-axis. 0) y-coordinates of points on the ( 2, 4) → ( 2, 8) graph increase by scale factor 2. (1, 1) → (1, 2) y y = y 2f(x) ( = f(x) 2, 8) Sketch the graph. Label some points. ( 2, 4) (1, 2) (1, 1) x 0 1 b Graph of f (2x) is a dilation, scale factor , parallel to the x-axis. 2 (0, 0) → (0, 0) (2, 4) → (1, 4) x-coordinates of points on the 1 graph increase by scale factor . 2 ( 2.5, 6.25) → ( 1.25, 6.25) y ( 1.25, 6.25) y ( = f(2x) y = f(x) 2.5, 6.25) (1, 4) (2, 4) 0 x 10.1 A frog into a prince 3 5 9 y Practice 4 2 1 Copy this Sketch same sketch the of graph f of (x) = g (x) (x = 1) 2f (x) . on the axes. 1 2 f (x) = 0 (x 1) x 1 y 2 2 Copy this sketch of f (x) = −x + 4. 2 f (x) Sketch same the graph of h (x) = f (2x) on the = −x + axes. 0 x 2 2 y 2 3 4 4 Copy this sketch of f (x) = x + 2x 3. 2 Sketch Sketch the the graph graph of of g (x) = h (x) = f (3x) −f on (3x) the on same the axes. same f (x) = x + 2x 3 axes. 0 3 1 3 2 4 Draw the graph of Draw the graphs f (x) = x 1 of g (x) = f x 2 on the same and h (x) = f (2x) axes. 2 5 Describe the transformation that maps the graph of y = x to: 2 1 2 a y = 2 3x b y = 2 x c y = (4x) d y = 2 1 x 3 2 6 Write is down the transformed equation by a of the graph which results when y = x dilation: a scale factor 5 parallel to the y-axis b scale factor 4 parallel to the x-axis parallel to the y-axis. 1 c scale factor 3 7 Describe the transformation that takes the blue graph y a 2 y = red x y 3x the 2 b y to 7 + 2 2 x 2 y = x x 2 y 3 6 0 10 Change = −(x 7) + 2 graph: x A LG E B R A You need to quadratic be familiar functions Combinations ● Any linear applied ● Any – of with types of transformation reection and for linear and dilation. transformations: function one three translation, after quadratic can the be other function dened to can the be by one function dened or y by more = transformations x. one or more transformations 2 applied Example one after the other to the function y = x 5 2 List the transformations applied to the function 2 a y = x 6x the + 4 b transformed 2 a x = x to give: 2 + Sketch y y = −3x 12x 11 graphs. 2 + 6x + 4 = (x + 6x) + 4 Write the function in vertex form. 2 = [(x = (x + 3) 9] + 4 2 + 3) 5 2 Start with the original function y = x 2 Start with f (x) = and x apply one transformation at a time. y f (x + 3) is a 8 horizontal 2 y translation of = (x + 2 3) y = x 3. 4 f (x + 3) 5 translation is a vertical of 5 on f (x + 2 3). 0 6 5 4 3 x 1 2 4 2 y = (x + 3) 5 6 2 b 2 3x 12x 11 = −3(x + 4x) 11 2 = −3[(x = −3(x + 2) 4] 11 y 2 + 2) + 1 3 2 y 2 Start with f (x) = = 3x 2 2 y = x 3x = parallel 3f to (x) the is a dilation y-axis, 2 scale 2 y = −3(x + 2) + y 1 = x 1 factor 3. 2 y = −3x = −3f (x) is the x reection in the 2 x-axis. 1 2 y is = a −3(x + 2) = horizontal −3f (x + 2) translation of 2. 2 y = −3x 2 2 y = −3(x + 2) + 1 = − 3f (x + 2) + 1 2 is a vertical translation of 1. y = −3(x + 2) 3 10.1 A frog into a prince 3 61 Reect ● Why and is the Example ● In 5 discuss quadratic in Example order 5b, 3 changed to does show it from the matter standard form transformations in which order to ver tex that you have apply form been in applied? the transformations? ● Why is Practice 1 List a y the = it best to do the translations last? 5 transformations −4x b y = applied 2x to the 9 c linear y = function 0.5x + y = 4 x d to y give: = −1.2x 2.5 2 2 List the transformations function. Sketch the applied graphs of to the the y = 3 y = x Express y = + 8x g (x) a f (x) = x c f (x) = −2x + 16 in 5, e f (x) = 2x g f (x) = x 3(x e terms g (x) 5, = of y f (x) 4x g (x) = h f (x) = 4x = and + + 3x, g (x) = a to f (x) = + 6, y = −x + 4 3x state + the 5 9 f y = −0.5x transformation b f (x) = 2x + d f (x) = −2x 5, 4x applied g (x) 5, + 3x 12 f f (x) = −3x = g (x) 6x = + to + 1 f (x) to get g (x): 5 2x 5 2 + = (x 2) 5(x 2) + 6x 7, g (x) = −3x 6x 7 6 2 8x in + 12, terms g (x) of = f (x) x 2x and + state 3 the combination 8, g (x) = −3x + 3 b f (x) = 2x 2 f (x) = x e f (x) = 4x of transformations + g f (x) = x 4x, g (x) = x 4x + + 7, g (x) = −4x 2 Problem 4 d f (x) = 2x f f (x) = x 2 5x 3, g (x) 6, g (x) = x applied to 3 = x 2 2x 3, g (x) = 2 + 5x + 2 2 2x + 2 2 each 12x g (x): c For each 2 2x g (x) 2 5 give 2 5x g (x) get to 2 2 2 Express c 20 2x x 2 9) 2x 2 f (x) = 2 2 4 y 2 b 25x 2 d function transformations. 2 a quadratic −x 6x + 4 h f (x) = (x) is x x + 1.5 2 + 4x + 4, g (x) = x 2 + + 6x + 9 2 + x + 1, g (x) = 9x 3x + 1 solving pair of graphs, the orange function f obtained by applying one 2 transformation to the blue function f (x). Express 1 f (x) in terms 2 of f (x), and state the 1 transformation. a b y f c y y (x) 1 f (x) 2 f (x) 1 0 x 0 x f (x) 2 f (x) 1 0 f (x) 2 3 6 2 10 Change x A LG E B R A d e y y f y f (x) 1 (x) f 1 0 x f (x) 2 f f (x) (x) f 2 2 (x) 1 0 0 6 For each pair of graphs, the orange function f (x) is x x obtained by applying 2 two or more transformations to the blue function f (x). Express f 1 of f (x), and state the (x) in terms 2 transformations. 1 y a f y b f (x) (x) 1 1 x 0 f y c (x) 2 x 0 f 0 (x) x 1 f (x) 2 f (x) 2 Translation, of any reection and dilation transformations can be used on the graph function. Example Here is the 6 graph of function f (x) and y the 1 transformed function f 3 (x). 2 f f (x) (x) 1 2 2 Identify take f the (x) to transformations f 1 that 1 (x). 2 Hence write the function f (x) 0 as 8 2 7 6 5 4 3 2 1 x 1 1 a transformation of f (x). 1 2 3 4 There has been a translation There has been a dilation 3 units to the left. The minimum points at y = parallel to y-axis scale factor 1 have been 3. transformed to minimum points at y = f (x) → f (x + → 3f (x 3) translation 3 units left 1 Therefore, f + 3) (x) dilation = 3f (x + scale factor 3 parallel to y-axis 3) 2 10.1 A frog into a prince 3 63 3. Example Given the 7 graph of f (x), draw the graph y 1 of f (x) = 5f 2 ( x). 1 f (x) 1 x f ( x): reection in the y-axis. Identify the transformations. 1 5f ( x): vertical dilation of scale factor 5 Multiply the y–value of all points by 5. 1 y y f ( x) f 1 (x) 1 5f ( x) 1 x Draw the graph of each transformation. x f ( x) 1 Practice 1 For each 6 pair of graphs, nd the transformations applied to f (x) to get 1 Hence write the function f (x) as a transformation of 2 f f (x). 2 (x). 1 y a y b 6 6 f f (x) (x) 1 1 5 5 4 4 3 3 2 2 1 1 (x) f 2 0 9 8 7 6 5 4 3 2 1 0 x 1 2 3 4 5 7 6 5 4 3 2 1 1 2 2 3 3 4 4 5 5 f (x) 2 6 3 6 4 10 Change x 1 1 6 2 A LG E B R A c y y d 5 5 f f (x) f 2 (x) 1 (x) 1 4 4 3 3 2 2 f (x) 2 1 1 0 4 3 2 0 x 1 1 2 3 4 5 4 6 3 2 6 graph of f (x), draw the graph of f 1 (x) = 2f 2 (x 5 5 6 f 4 4 5 a 3 3 4 the 2 2 3 Given 1 1 2 2 x 1 1 (x). 2 3) b 1 f (x) = 2 f ( x + 5) c 1 f (x) = 0.5f 2 ( x) 1 5 5 5 f (x) 1 f 4 4 (x) 4 1 f (x) 1 3 3 3 2 2 2 1 1 1 0 x d f (x) 0 x 2 2 3 4 2 3 5 4 3 1 1 2 2 2 3 3 3 4 4 4 5 5 = 2 3f (x 5) e 1 f (x) = −2f 2 (x) f 1 y f (x) = f 2 y ( x 2 1 x) + 3 1 y 7 5 4 4 3 3 2 2 1 f 6 (x) 1 f 5 (x) 1 4 3 f (x) 1 2 1 1 0 1 x 1 2 3 4 5 0 1 0 4 3 2 1 x x 1 1 2 3 4 5 6 7 8 1 1 1 2 2 3 2 3 4 3 5 4 10.1 A frog into a prince 3 6 5 Transformations D ● If the the ● If graph of original two dierent Exploration Use f 2 (x) Find is mx c value these to and functions the In + of has the function is function been transformations function, are the give the the same as the graph of transformed? graph transformations of the really same dierent? 5 technology = not? transformed function, transformed 1 a or graph their where c in graphs, the these are dierent reections the graphs linear in of the f (x) functions y-axis and and f ( of the the x) form x-axis, are the f ( same. x). What graphs? original function and the transformed function identical? 3 For one of your graphs transformation the y-axis. original 4 What f Does point? single ( x) the How in to step that resulting does pick point this transformation 2, point point on reecting have aect is a by the your same answer equivalent to the it the line. in the Apply x-axis coordinates to step two the and as then the 2? combined reections? Example 8 2 Consider and h (x) the = f function (2x) both f (x) = 2x generate . Show the that same the transformations g (x) = 4f (x) graph. Find the function generated by g (x) = 4 f (x) = 4(2x = 8x = f = 2(2x) = 8x = h (x) the rst transformation. 2 ) 2 Find the function generated by h (x) (2x) the second transformation. 2 2 Both the functions generated by the g (x) two dierent transformations are equal. The two transformations Reect ● In and Example generate discuss 8 the the same graph. 4 function g (x) is a vertical dilation by scale factor 4 of the 1 function f (x). The function h (x) is a horizontal dilation by scale factor . 2 Do g (x) and h (x) transformations represent the same of the function on the parabola f transformation or dierent (x)? 2 ● Choose to that other? 3 6 6 a point point. How Do does the two this new aect 10 Change f (x) = points your 2x . have answer Apply the each same above? of the transformations coordinates as each A LG E B R A Summary Translations ● y = f (x Reections h) translates y = f (x) by h units in the ● x-direction. ● y = f (x) + y = the f (x graph graph k translates y = f (x) by k units in the ● y-direction. ● The The of graph graph h) + k x-direction translates and k y = units f in (x) by the h units y of y of = f of = f y = (x) y −f = (x) (x) in f is the ( x) in a reection of the of the x-axis. is the a reection y-axis. in y-direction. Dilations ● y = a f factor ● y = f (x) a, (ax) factor , is a vertical parallel is a to dilation the horizontal parallel to the of f (x), scale y-axis. dilation of f (x), scale x-axis. af (x) f (ax) y y C C C 2 C 2 1 1 2 C f (x) = x f (x) = (4x) 1 2 a > 1 C f (x) = x f (x) = 4x a 1 > 2 1 C 2 2 C 2 0 0 x x 1 vertical dilation scale factor 4 horizontal dilation scale factor 4 y y C C 1 1 2 C f (x) = f (x) = x 1 2 C x 1 2 1 C 2 C f (x) 2 4 0 < a < 1 C 2 1 C 0 < a < f (x) 2 = x 2 1 4 0 vertical Combinations ● Any linear more of 0 x dilation scale factor horizontal dilation x scale factor 4 transformations function can transformations be dened applied one by one after or the ● Any or quadratic more function can transformations be dened applied one by after one the 2 other to the function y = x. other to the function y = x 10.1 A frog into a prince 3 67 Mixed practice 2 1 Here is the graph of f (x) = x 2x 1. b 6 5 7 f (x) 2 4 6 5 2 4 2 f(x) = x 2 x 1 1 3 2 0 4 3 x 2 1 1 f (x) 1 2 x 4 3 2 1 c 2 6 Use this graph to help you sketch the graph f of (x) 2 5 each function and write down the coordinates 4 of the new vertex. 3 a f (x + 2) b f (x) 4 2 f (x) 1 c f (x) d f ( x) e 2f (x) f f ( 3x) g f 1 0 7 (x + 1) 3 h 3 f j 5f 6 5 4 3 x 2 1 (x) 2 i 2f (x) 1 ( 0.5x) + 4 3 2 State which combination of transformations has 4 been applied to f (x) to get g (x): d a f (x) = x, g(x) b f (x) = −3x c f (x) = 12x = 2x 8 8 6, g(x) = x + 5, g(x) = 6x 2 6 f (x) 1 + + 6 4 2 d f (x) = 2 x + 4x + 4, g(x) = x 5 2 2 e f (x) = (x 2) 2 + 1, g(x) = (x + 1) 2 0 x 2 2 f 3 f For (x) = each 2x + pair 8x of transformation + 4, g(x) graphs, applied = x nd to f + 4x the down the function f (x) to + 4 2 4 single get 1 Write 2 2 f f (x) 2 6 (x). 2 (x) as a 8 2 transformation of f (x). 1 e a 4 f 4 (x) 1 3 3 2 f (x) f 2 (x) f 1 (x) 2 2 1 1 0 4 0 4 3 2 x 2 3 1 4 1 2 3 3 5 5 3 6 8 10 Change x A LG E B R A c f 6 f 4 (x) f 2 (x) 1 5 3 4 2 3 1 2 0 f (x) 5 1 4 x 2 3 2 1 1 2 0 4 x 3 1 3 f (x) 2 4 d 6 5 4 4 For each pair of graphs, nd the transformations f (x) 2 applied to f (x) to get 1 function f (x) f (x). Write down 3 the 2 as a transformation of f 2 (x). 2 1 1 a 0 8 7 6 5 3 x 2 2 1 5 f (x) 1 2 4 3 3 f (x) 1 4 2 5 1 0 3 x 2 2 e 1 6 2 f (x) 2 5 f (x) 2 4 b 3 6 2 f 5 (x) 1 1 4 f (x) 1 3 x 4 3 1 5 1 2 1 3 0 4 3 x 2 2 4 1 5 2 3 f (x) 2 4 5 10.1 A frog into a prince 3 6 9 5 f Given the graph of f (x), draw the graph of f 1 (x). 2 6 5 4 f (x) f 2 (x) 1 4 3 2 1 1 0 x 2 0 6 5 4 1 3 1 x 1 1 2 2 3 f (x) 1 3 4 a f (x) = 2f 2 (x + 4) b f 1 (x) = f 2 (2x) + 4 1 5 c f (x) = −f 2 Review in ies an freely d f (x) = 2f 2 ( x) 1 context Orientation Whenever (2x) 1 in object through space such the as air, and a ball, its time arrow, motion is or dart aected 2 by A student throws a ball from a window in a tall building. 2 gravity. Any object which isn’t self-propelled x (like Its a bird by a or its rocket parabola. directly The a This downward path that trajectory. gives would the an and takes in of terms a path gravity exerts equation (y) follows because object The height is be) a in a ight is the acts (0, known u as travelled h) is a usually A frog leaps its is on unit a lily pad. Viewed from position horizontal represents trajectory 1 of is and given by (0, 0). on eect graph the y-axis is the where , of which velocity of the it is in thrown and m/s. increasing the value of the value of trajectory. the eect of increasing A of the trajectory. baseball player is practicing her batting on an range. Let (0, 0) be the point at which vertical; ight is given by y = f hits the ball. The indoor range is about than the point at which she hits the 5 m ball. (x) a ( x ) = graph The Her rst hit follows a trajectory given by 1 2 f h − 5 meter. its 3 where = the higher The the from horizontal the Describe she 1 position initial indoor x-axis y (x). from initial the Describe h 3 side, is its u 1 by horizontal b distance given u force. trajectory of is given always constant trajectory x − y 4 2 1 x = − ( 4 x − 10 + 5. ) 20 a Draw a graph of its trajectory. i Describe the transformations that map a 2 b Find the distance it travels before returning curve to with equation y = x onto starting curve 2 1 its a height. with equation y = − x ( − 10 ) + 5. 20 c The frog can change its jump by modifying ii the angle and speed with which it Show point o. Describe clearly how its jump would its new trajectory were given (0, y = f (2x) ii y = 1.2 f Use (0.7x) iii y = f ( the graph curve hitting Explain model 37 0 a clearly why trajectory y for = −0.8 f the 10 Change curve passes through the described. transformations (x) frog’s does jump. not whether the to maximum height of x) this d as by determine i this 0) vary iii if that launches is point more and than hence 4 meters would above hit the her roof. A LG E B R A b Her second shot follows y a trajectory given by b Draw c Find a graph of this relationship, b(t). 2 1 = − ( x − 10 − 100 ) 40 . b(50). State what this amount represents. By considering the graph coordinates of transformations, the maximum nd point of the d curve. Hence determine whether or not Find the ball will hit the Car loans month, (the use the loan simple amount balance) interest you owe decreases so that, on by the the every (House loans or Suggest this way.) car Suppose loansand $150per do Write you have $12 you are making payments to represent as months that a function of the Reect and How you have gone by change(s) produce the what a same State o a parallel to the graph scenario with a higher change(s) graph with a to the lower scenario could y-intercept how the increase graph your will be original transformed payment to the number month. Write down an equation for of scenario. (t). statement of inquiry? Give specic examples. Statement of Inquiry: Relationships predict model duration, patterns frequency of and if $250 discuss explored but x-intercept. loan new have what Suggest per (b) pay of g equation balance to 000 month. an you not you a take same mortgages the in will y-intercept. produce work it loan. could loan f amount. long ceiling. e 4 how the change that can help clarify and variability. 10.1 A frog into a prince 3 71 this A 10.2 thin Global line context: Objectives ● Changing the divides Scientic Inquiry subject of a formula and us technical innovation questions ● What ● How is the subject of a formula? F ● ● Simplifying rational algebraic expressions can you change the you simplify subject of a formula? Performing algebraic mathematical operations on rational ● expressions How can a rational MROF expression? ● How do operations on rational algebraic C expressions rational ● Does compare numerical technology to operations on expressions? help or hinder D understanding? ATL Use Organization appropriate skills strategies for organizing complex information 10.2 Statement of Inquiry: Representing helped change humans apply and equivalence their in a understanding variety of of forms scientic has principles. 11.3 E10.2 372 A LG E B R A Y ou ● should simplify already know how fractions 1 to: Simplify each fraction. 4 14 a b 16 35 2 2 20 x x c d 2 3 ( 20 x ) x ● factorize quadratic expressions 2 Factorize. 2 a x + 5x + 6 2 b x 3x 10 2 c ● solve a linear equation algebraically 3 x Solve. a 2x 1 = b 5x 7 = c Rearranging F You What ● How can you change ● How can you simplify already solution x equation = to equations 2 c 2 = know 3. solve + b = 8 for show when a = = a 2 7 A or 2 2 By + an the is b is innite In by an You 3 and b a = 8 4x + 17 formula? the a subject of rational linear a like ‘isolating know how between formula? expression? equations called also = to the use 5x x’ 7 or = 8, for which has ‘rearranging substitution variables, to the solve example, solving 4. 2 + b 2 are equation sets of both that values. on for values words, the equations, describes Each values an variable of the but c 2 = + algebraic in a other 2 a b is also a relationship formula can take formula. between dierent variables. = 3, of for b = other a and values you can 4, c = formula: b you for solve b can and for is also of nd c a you any of valid for values a, a = b, 5, and corresponding can the nd a b = 12, c = c value for c. corresponding variables, 13 given the value values of 1 between F = C + degrees Celsius the temperature in °F 2 Find the temperature in Celsius °C, you used need to to solve solve the and degrees Fahrenheit is given 32. Find have It combinations 1 in 5. two. relationship the a number Exploration by x’. substituting other other The solve sometimes 2 valid substituting a. of relationships depending Similarly , for to 1 2 a and c more values, = and formula two c is + 2 a 5x subject how This that the 8x 5 formulas ● is 9 an when it is 35°C. when equation. it is 77°F. Carefully To nd write a temperature down the steps you equation. Continued on next page 10.2 A thin line divides us 373 3 Using the nding same F and steps nish as you with a used in formula step for 2, C. begin C is with now the the formula ‘subject’ of for The the formula. a Use your new formula from step 3 to nd the temperature in it is 77°F. Compare your answer to that in step Write down formula’, what and the you think necessary it means steps to to do ‘change the 0°F. subject of the formula is a subject of the and this. way of In boils The variable in Reect ● In When the and are formula ● discuss Exploration What When 1, does between the rearranging the solving it be theorem the side other and and an based 2 2 c 2 c = a = a 2 2 you solve a = a = c and 100°C. dierent the subject of the formula change the C? dierences between changing the subject of a to change the subject of a formula? states that a is c in a right-angled 2 = a triangle, the relationship 2 + b , where c is the hypotenuse and a and b 2 + b to make a the subject of the formula. + b + b 2 2 2 b Subtract Rearrange 2 2 b from both sides. Take the soyou square can root ignore the variable factorize 3 74 you so are that trying the to isolate variable 10 Change appears appears only more once. than once in the of the Now formula, the terms so that the 2 b variable When at 2 b a 0°C algebraic 2 2 b at scale water sides. 2 = c 2 c formula, on equation? useful lengths two 2 Rearrange a 212°F. 1 2 are of at 32°F 1 Pythagoras’ between subject changing F similarities and could Example change scale, at formula. relationship ● you this Celsius boiling relationships. salt freezing freezes freezing the on 2 is Changing of water water 5 based Celsius at when was mixture and 4 Fahrenheit scale a is a is on both the sides. negative the left a is square subject of hand a side. length, root. the formula. A LG E B R A Example 2 ATL Rearrange to make m the subject. Multiply Ft = mv Ft = m Practice 1 both sides by the denominator mu (v of the Factor u) Divide right out both m hand to side. isolate sides by v it. u. 1 Rearrange each formula to make the variable in brackets the subject. 1 2 a y = 5x 4 [x] b y = x + 3 [x] 3 2 c p e V = m + 2 2 [m] d V [V ] f V = (2w 5) [w] You may seen some have 2 = V f + 2ad i i = V f + at [a] of these i in science. 2 V g I mV = [R] R h F = [r] + r r 2 1 mV 2 i F = [V] j F = mV + mgh [m] 2 r 3 RT 2 k μ = [M] l c = (3a + 2b) – 1 [a] M 2 Write down subject 3 The of the the formula formula for the area A of a circle with radius r. Make r the formula. for the volume V of a cone with height h and base 1 2 of radius r is V πr = h. Make r the subject of the formula. 3 4 When driving a car, if you accelerate from rest at a constant rate a for an 1 2 amount of time t, the distance d travelled is given by the formula d = at . L 2 Rearrange 5 The time the formula taken (T ) for to a make t the pendulum subject. to swing once each way and back L to its starting position is given by the formula T , = 2π where L is the g length of the Rearrange the Problem 6 Between pendulum. formula to make L the subject. solving any two charged particles with charge q and q 1 , there kq force. You can calculate this force using the formula is an electric 2 q 1 F = 2 , where r is the 2 r r q 1 distance between the particles. Rearrange the formula to make r the q 2 subject. 10.2 A thin line divides us 3 75 A rational algebraic expression is a fraction that contains The variables. Ancient Egyptians images Factorizing the can numerator simplify the change and the fraction, rational as you would 12 For algebraic denominator fractions have a a to common numerical a simpler factor, form. you can When divide to fraction. fractions same to 20 in way the they represent did words. Horus was a sky 5 god (x used represent 3 = example x to 2) whose shattered x eye into was six = (x − 2) ( x + 5) x pieces. + 5 of his eye Each shattered represented dierent Exploration fraction. Interestingly Simplify these fractions completely. Justify each add step. the six together a b Some d e you 3 h a For the one fraction. each simplify of it a 4 For each 5 Based x ● The on before ● To Why and/or the or a of in step to discuss a variable you need rational = 3, state steps to have in the denominator explain the steps needed to that on nd the 10 Change 3 any and c value 3, that write x = cannot down the x take. steps for expression. are not allowed variable. Justify you Do your restrictions expression, rst. 1 x 2 simplify? to allowed expressions, algebraic restrictions you not is. expression. answers after are that b denominator 37 6 rational given rational and do simplify a you why 3 your values called + the i that expression simplifying Reect these to = value Explain 1. consider demonstrate possible. of get than perfection State you this f to g if fractions c rather 2 a 2 ATL 1 part on may in you the nd denominator these are restrictions answer. the need variable? to What factorize the are they for? numerator is that not A LG E B R A Example Simplify 3 completely and state any restrictions on x Factorize The the x ATL ∉{0, 2, are denominator 0, numerator any values including and that any denominator make the cancelled completely. expressions when in simplifying. 7} Practice Write restrictions the these 2 expressions in their simplest form. State any restriction(s) on the variable. In 3 5 10 a 4 5x 1 6 + 3x 42 x 2 the 4 2a simplest 3 2x 35 x numerator 7 y and (x − 7 )( x + 8) (a − b )( a + 2b ) x 5 + 6x + 7 )( x + 8) (a 2 x x − 12 − a) + 7x − 3x x − 10 2 − 12 x x − + 32 x 9 2 2 − + 10 3 x common factors. x 8 2 x 2b )( b 2 + 7 − no + 8 6 2 (x denominator have 2 4 form 5 y 3 6 x + 2x x − 35 − 7x + 12 2 x + 4 x − 21 10 2 x − 3x − 18 Problem 11 Write an solving unsimplied expression in the rational numerator expression and the in x that restriction on x 12 Write a rational expression in x which simplies Operations on rational x a that quadratic x ∉{ 2, 5}. + 3 to , x C has and where x ∉{6, 10}. 10 algebraic expressions ● How do operations operations You can multiply and on on rational divide rational algebraic numerical algebraic expressions compare to expressions? fractions in the same way as numeric fractions. Exploration 3 1 fractions Multiply these i simplifying ii multiplying rst, rst, by: and and then then multiplying, simplifying. Continued on next page 10.2 A thin line divides us 377 Explain which method a 2 Use you found b your easier. c preferred method from step 1 to multiply these algebraic fractions. a , x ≠ −3, x ≠ b −5 , x c 3 , Divide your these fractions, Use x 3, 1, ∉{2, leaving your ±2} 3, ±4} answers in simplest form. Explain method. a 4 ∉{ b your your method in c step 3 to divide these algebraic fractions. Explain method. a , x ≠ −3, x ≠ −5 b , c , x x ∉{±3, ∉{2, 0, 3, 5} ±4} The Reect and discuss reciprocal 3 of ● Write down two equivalent fractions. Take the reciprocal of . It is the each. multiplicative inverse. Are ● the What new are fractions Example Simplify fractions the and also dierences equivalent? between multiplying and multiplying dividing and numeric dividing algebraic fractions? 4 completely and state the restrictions on the variable. Factorize To divide by a the fraction, quadratic multiply by expressions. its reciprocal. Simplify. Include , x ∉{± 3, values of x that original expressions 378 make the 4} 10 Change equal to 0. denominators of the A LG E B R A Practice Simplify 3 each rational expression. State any restrictions 3 25 p 66 p 3 p × 1 4 5x 5k + 10 24 p 6x 10 c 6x 18 12 y 4 x x + 8 2 + 3 y 3 x − x − 2 x 1 a × 5 2 + 2x x + 1 − 10 2a + 2x − 3 − 6 2b ) 2 x + 5x − 24 x 2 x + x − + 2x − 48 ÷ 2 x (a 8 2 + 2 b 2 x × x + b 2 a 2 − 3x 2 a ÷ + 1 2 x 7 + 9y 2 ab 3 − 2x 6 2 x 3 ÷ 4 9 c 3 5c × 3x variables. ÷ 5 3 the 5 c 2 55 k on 2 x 2 − 9x + 18 x 2 + 3x − 18 2 2 2 x 9 2x 4 x + 3 Reect ● before ● In a + 5x and Should you or nd nding are series two or resistance in (R 6 the + − 10 2x 2 x 6x 4 + 12 2x 1 Find a R the = on the Explain when would variable your the the ways For you Explain of nd your connecting components circuit R ohms, R in a multiplication the restrictions = R 2 ohms, R = 3 ohms, or electrical connected is: components in parallel, (where together: the R , total R , ... are 2 in a circuit = 8 ohms = 6 ohms = 5 ohms with: R 2 When two combined 3 before 2 1 2 – reasoning. 2 1 c 4 components). resistance 1 b + reasoning. 1 of + 5 6x 4 of total 4 + 4 reciprocal? possible resistances 6x 2 x tot the − ÷ 2 4 x restrictions question, the parallel. ) 2x multiplying? Exploration There + discuss after division after 10 2 x − 3x ÷ 2 − x 6x ÷ 2 x in 2 × 9 Write resistances resistance down a are is connected greater necessary step or less before in parallel, than the adding determine individual fractions if the resistances. together, and explain. 4 Find twice 5 Find an expression the an resistance expression resistance 2 ohms for of for the the the more total resistance when one component has when one component has other. total than resistance the a other. 10.2 A thin line divides us 379 Example Find each 5 rational a expression in simplest form. b If a × × there is between the LCM no the is common factor denominators simply the then product of the denominators. Simplify x ∉{ 5, your nal answer completely. 3} There is a common factor between b the two denominators: (x 2). × With now x Practice In C. organize Practice any 3 4, show each on the the using steps in a 3} logical your str ucture. working expression. 4 x the in a logical order. Remember to include variables. rational + 1 add Communicating information restrictions Simplify common 4 Objective: v. ∉{2, a State restrictions 1 3 1 2x 4 x 2 y any on variables. 1 2 + 3 the 3 + 4 2 3x ab 6x 5 − ac bc 2 1 1 x + 2 x − 1 2 x + 5 x 3 8 0 + 4 − 10 4 8 10 Change x + 4 − 5x − 24 x + 3 − 1 2x + 1 x x 2 6 + x − 8 x 7 11 2 x x + x − 3 + 10 + 3x x 5x 2x 2 2 7 6 9 x x 5 x + 5 3 5 x − − x 3 5 + 12 x + 1 x + 3 4 x − 5 denominator, terms. you can A LG E B R A You have fractions. ● seen Simplify dividing ● To that algebraic Simplifying, rational by multiply multiplying ● To divide ● To add rational It is behave and by in rst the expressions, ecient in much dividing factorizing numerator multiply to the involve the simplify the and same very as numerical processes: expression, and then denominator. numerator the way similar rational and multiply expressions the before them. expressions, subtract rational multiply by expressions, the rst reciprocal rewrite the of the divisor. fractions with a denominator. Finding D factors more rational and common expressions common denominator. fractions multiplying, restrictions on variables using technology ● Does technology Exploration 1 Exploration or graphing Describe 3 State 4 Explain 5 Repeat 6 Explain you saw to hinder or not that draw similarities whether expressions 2 software any or understanding? 5 In 2 help the or simplies the graphs dierences GDC or of to both between graphing x 3. Use your GDC expressions. the graphs. software has graphed both correctly. whether steps 2 or to whether 4 not you think for you both which should expressions simplies always trust to results x are + you equal. 3. obtain using technology. Summary ● A formula algebraic is an equation relationship that describes between two or an Rational ● sets of values. Each variable in a expressions: more formula must exclude denominator take of ● dierent the other Changing way of the A It or on in the algebraic contains of the the formula rearranging usually variable rational that subject changing, dierent depending involves is the values of x that make a in the expression equal to 0 values variables. relationships. ● values, all can a algebraic isolating a ● can be simplied ● can be multiplied, subtracted using by dividing divided, similar common added, rules as factors or for numerical fractions. formula. expression is a fraction variables. 10.2 A thin line divides us 3 81 Mixed practice 3 2 Rearrange the formulae to make the variable in y 16 x + 11 2 y 15 z × 12 3 x brackets the 500T 3 3 V πr = [r] 2 P = x [T] 3 2 v 2 y + m 3 y 3 x − 3 y 4 y x 4 y 1 m 1 F x ÷ 13 x 3 8 xy 5z subject. 4 1 5 2 2 [r] = G W 4 = CU [C] 2 2 r Simplify 2 5 E = mc [c] v 6 c v c + v the = v these expressions. State the restrictions on variable. [c] 0 x − 2 y 1 + 2 xy 7 14 4 Simplify each restrictions rational on the expression. State x x − 7 x x + 1 x x 1 x + 5 any variables. 3 2 + 16 7 4 12 x 5 + 15 5 5x y 7 x 4 17 x + 9 8 + 4 6x 8 3 36 xy 4 x 9 9x 18 2 x − 4 x − 21 x 9 + 4 3 1 x 1 a + b − a b 4 4 10 2 x 2 − 8x − 33 x 16 x + 1 2 + 20 6 Review in Scientic x − x x 2 context and technical innovation h Find the time described 1 5 + 19 2 x An important relationship in the study of i , = where V is the velocity of an is Find or distance and t is the time taken. has exercise, speed a cruising consider for the speed this entire of speed 870 to An the In On a ight ying with from j average ight. a headwind to of Montreal, 40 wind speed km/h. if the and ight speed of the it the wind tailwind) minutes if speed the and 30 and ight direction took Find the 2 When resistors are connected in the A333. return ight, it is ying with a km/h. Find the actual speed of the Write down of the A333 an expression with a for headwind the of x is R given + R Write down of the A333 an expression with a for headwind the of y actual speed distance resistors actual Write 5560 between Brussels and e Make Find connected an of one a of smallest . R 3 the sum in series, of the the total expression for individual circuit them is resistor with 3 the total resistors, 4ohms and the larger largest than resistor Montreal 2 ohms t the the subject time it of the larger than twice the smallest takes to travel Simplify Find the without b any Write down resistance time it took on the ight the described an expression when one in a a is in a. Then a a 10 Change into a single resistor for the connected the total same in as series the to the in circuit 3 8 2 expression fraction. formula. largest part = R 2 km. wind. g are simply down where one. f is resistance speed km/h. is is + R total 1 resistances. the The the 1 + by parallel, km/h. a d (headwind hours A333. resistance c and tailwind When 30 6 1 1 of (headwind hours seconds. tot On 6 is resistance b ight direction took 1 actual return minutes. Find or Brussels the this 2 a on b Airbus km/h. be the tailwind) 57 A333 took object, t d it part motion d is V in single fraction. simplify the expression into A LG E B R A 3 Ohm’s an Law states electrical that circuit the with voltage current (V ), (I ) in and Problem 4 resistors, R and r connected in series, is given Scientists = IR + calculate the gravitational force by between V solving two any two masses (m and m 1 Ir. Gm formula F using 2 m 1 the ) 2 = , where r is the distance 2 a Make I b Circuit the subject of the formula. r between A has a resistor (R) of 6 ohms and a smaller resistor with resistance r, series. Circuit B has a resistor Determine (R) of and smaller a smaller resistor in resistor Circuit three A. times Circuit A a B are voltage the total of connected 12 volts. current in parallel, Find owing an in of the gravitational constant. many times larger the force gravity is when masses is the distance between the halved. the and One mass is doubled and the distance have expression both how circuits between the masses is factor Determine increased by scale for 4. the eect on the in gravitational terms is and b circuit G 5 two ohms and connected of in them a force between them. r c One the mass is distance scale factor doubled, between 4. the other them Determine is is tripled reduced the eect and by on the Tip gravitational The total current is divided between if they are connected in One mass force minimum a gravitational equation speed rocket) for eld the required to break is called escape for free an of halved to the larger. and change Find the other to keep how the the is made distance gravitational same. object Earth’s ‘escape velocity is times needs (usually them. parallel. eight The between the d circuits force v velocity’. of an The object is e 2G m E given by: v e = where G is the gravitational r constant, m is Earth’s mass, and r is the distance E between The is Earth’s escape center velocity approximately Now, fuel rockets to This break fuel more lighter objects 000 a mass miles you need and How you object. the Earth hour. amount of gravitational weight more the leaving per Earth’s discovering Reect and tremendous from considerable vehicles, have for require away adds thrust, 25 of fuel. to It’s more the a pull. rocket, vicious ecient and circle fuels and thus that new it takes more scientists methods thrust hope of to to lift it. overcome But by to create building propulsion. discuss explored the statement of inquiry? Give specic examples. Statement of Inquiry: Representing helped change humans apply and equivalence their in a understanding variety of of forms scientic has principles. 10.2 A thin line divides us 3 83 r Getting more done 10.3 in less Global time context: Objectives ● Finding a Globalization Inquiry constant of ● proportionality and sustainability questions How do you nd a constant of F ● proportionality? Setting up equations direct to and model indirect a proportion ● situation What MROF look ● Graphing ● Recognizing direct and direct indirect and does a proportional relationship like? relationships inverse proportion ● What ● How does it mean to be proportional? C from ● graphs Identifying tables of direct and inverse proportion does changing proportional from one variable relationship aect in the a other? values ● Can situations seem proportional when D they ● ATL Is are not? simpler better? Transfer Combine knowledge, understanding and skills to create products or solutions 5.1 Statement of Inquiry: Changing and always to simplied forms can help analyze the eects of consumption conservation. 10.3 E5.1 3 8 4 N U M B E R Y ou ● should express a already ratio as a know how fraction 1 Express in its a 5 c ● write linear real-life functions to model to: 2 : a : earns function b A graphs of linear functions 3 fraction 2 d 0.2 : per the 4 : 1.2 hour. Write amount he a earns in hours. taxi any draw a b £10 for ride costs mile. Write ● as form. 13.3 John h ratio 3 4.5 situations each simplest Draw a $2 plus function $4.50 for the per cost of journey. graphs of the two functions above. 2 ● draw graphs of quadratic 4 Draw functions If you the ● How ● What sell make much is a of you does as We variables constant ∝ x do means say the two to sell. If of in of you you directly as x’ the sell sell direct each of from y 3 = to x for integer +3. proportionality? mats, If x relationship quantities be values varies mouse you of graph variation constant money. said all a proportional much are ‘y a mats say for inverse nd items, mouse twice money. Two and identical number will y values Direct F the money twice half are look as like? you as many, directly proportion make many varies mouse you make with mats, half you as proportional. if, and only if, their ratio variable. or ‘y is directly proportional to x’. ATL Exploration A store 1 sells Write regular down regular Determine 3 Draw to 4 10 From a To by meet LED 2 Euros represent your variable the variables is representing per bulb. store’s and dependent, the by 4 growing for determine number b the bulbs to for income justify your from selling choice of letters to variable. graph, the 2 bulbs amount and of which money one made is independent. from selling up bulbs. your multiply Identify which graph light light function each 2 a a bulbs. represent 1 7 of c light by demand Euros per what bulbs 5 for happens to the income when you sold: d more by 12 ecient e by bulbs, 14 the station also sells bulb. Continued on next page 10.3 Getting more done in less time 3 8 5 5 Using the represent your 6 same the graph Determine to the Justify ● Describe a increases, ∝ x k is In x means called The and y a ● In ° ● a kx y is shop is a 1, money Justify if in one made your new function bulbs. Draw a to line on is in direct proportion answer. Exploration quantity constant called the a LED 1 go through increases, the the origin. other proportion. a linear form k, where constant, proportional of of sold. drew direct for down y to = or then ≠ 0. constant variation x, k the of variation. function relationship between kx. 2 identify the proportionality constant for the bulbs bulbs. the of constant the form ratio of x y = kx, and y. the proportionality Explain why you constant think this k is. 1 down number kx write selling 1 you relationships charges Write amount discuss light called Example A if light linear also = 1, from relationship. where, in step for: regular For is = Exploration LED this proportionality and function ° y in bulbs graphs not function Reect the light situation y words, is the that the of as income discuss but function other whether why of represent and ● y to number Reect variables amount of €1.50 a for a function liters of liter to of mineral represent mineral water water. the and relationship the total price between of the mineral water purchased. b Hence, c Show a determine that the number of proportionality liters and price constant. are in direct proportion by drawing graph. Continued 3 8 6 10 Change on next page N U M B E R a P l = = price number P (l ) b k = = so of liters 1.50l For every extra liter the price increases by 1.50 The c Dene the variables. P graph and l is a are straight in direct line that passes through the €1.50. origin, proportion. P 6 5 soruE 4 ni 3 The total price depends on the number of liters, so P is the ecirP dependent variable and N is the 2 independent variable. 1 0 l 1 2 Number If the graph graph can is be Reect ● How is linear ● a 4 liters straight written and the as line y = passing kx, discuss and through x is the directly origin then the proportional to equation of the y 3 proportionality constant represented on the graph of a direct proportion? Explain why represent Example The 3 of a a linear graph proportional that does not go through the origin does not relationship. 2 variable y varies as x. When x = 4, y = 10. ‘y Find the value of y when x = varies means 7. as ‘y is x’ directly proportional y ∝ x 10 = means k × that y = to x’. kx 4 ⇒ When x = 7, y = 2.5 × 7 = 17.5 Use the proportionality constant to nd 10.3 Getting more done in less time y when x = 3 87 7. Practice 1 The 1 variable represent a c if b c this is is directly proportional relationship. State to what doubled the variable happens b b d c if b. Write an equation to to: c is tripled 4 is added 2 c c if b is multiplied by if to b 3 2 3 4 The variable a Write b Find the c Find v P is the v is function value when directly t V Two variables Find the when P x the represents constant to V. to waste a Q are in direct from 4.7 reduce Mass of Verify When of t = 5, v = 40. proportionality. V = 3.2, P = 8.64. this proportion. table: 6.1 13.72 trash in Composting science dumped Number relationship t. solving waste. In variable proportionality. When 6.58 order of the the 5.4. values 0 farms. a that to 25. and missing Problem food = = Q In of proportional proportional Find x 5 directly of in landlls, produces experiment, a composter containers soil that (kg) the number many rich Kent at one people soil that records time the and are can beginning then be number the mass of 2 3 7 9 1.6 2.4 5.6 7.2 of containers and mass of of soil to used compost in gardens containers soil are or offood produced. in direct proportion. b Find the constant c Calculate the of proportionality. amount of soil produced from y 5 containers of food waste. 6 6 Determine which of these functions represent 5 d direct proportion, and nd the constant of 4 proportionality for those that a do. 3 2 e c 1 x 0 6 5 4 3 2 1 1 2 1 2 3 4 b f 5 6 3 8 8 10 Change 3 4 5 6 N U M B E R Objective: B. ii. patter ns describe In this Investigating Exploration, models the as you relationship patter ns general will r ules nd between a consistent general the time rule in needed with terms to plant ndings of a specic trees and function hourly that income. ATL Exploration In an eort products, they 1 the One total Hence, Copy hour and Time a can from it needed been summer take table to of harvested that trees 2400 income groups job 300 planting would the dierent have plant student’s complete 2400 that take long this the (t) plant can student how nd for trees income Determine 2 replace students plant. Find to 2 pays one 8 consumer cents per tree that hour. trees. one per in for student to plant 2400 trees. hour. show the time taken and income per students. 1 student 2 students 8 4 4 students 8 students to trees (h) Income (I) per 24 hour ($/h) 3 Predict the time calculations your 4 down a a the to of students trees is them halves by a same If and y ∝ are Write taken ● Does in x’ and Reect ● per hour Add for the 16 students. values for 16 Do some students to time and the income between the taken y Generalize this relationship the per pattern, between and the write number of hour. number of students and the time to are is directly income to plant the results proportional: hour. 2400 number inversely number per But trees. of The students proportional in the other doubling doubling time taken doing if the the to plant of the planting. multiplying variable the number being one of divided by number. an or the trees. proportional x table. relationship non-zero as and doubles non-zero y inversely this trees 2400 one the variables the x 2, students inversely Two income predictions. represent relationship plant Exploration number and your from to planting Describe needed pattern function students In needed check table. Identify 5 to ‘y inverse is linear inversely proportion, proportional you to can x’, say and ‘y you varies can write . and the to relationship plant the discuss 2400 function 4 between trees have a (t) the from number of Exploration constant of students 2 as a (s) and time function. proportionality? Explain. 10.3 Getting more done in less time 3 8 9 Graphs If y is inversely proportional to x, then y is directly proportional to of . are An equation or represents a relationship of called inverse reciprocal proportion Example It takes there the b Determine c Write Draw a 2 × time if down the the 16 = 2 hectares Find prepare inverse person 16 a d an graphs. relationship 3 one are or for this a to be one prepare relationship and of to the this one hectare of eld for planting and prepared. person function eld graph 32 days to to prepare represents represent number of the the 16 direct hectares or inverse relationship for planting. proportion. between the time to workers. function. days One person, two days’ prep time per person, total time = 32 days. b w: t: number time The prep This c t to of workers prepare time describes 16 halves an hectares as the inverse 1 2 4 8 32 16 8 4 number of workers doubles. proportion. ⇒ ∝ k Substitute = values for t and w, and solve for k 32 t d 35 30 Plot the points from the table of values. emit Even 25 noitaraperP own though right a the function smooth is curve, in its only the 20 points with integer values on the n 15 axis are meaningful since there can’t 10 be 5 0 w 0 1 2 3 4 Number 3 9 0 10 Change 5 of 6 workers 7 8 9 10 a non-integer number of workers. N U M B E R Practice 1 For i 2 each part a to e: Determine whether proportion or ii If there is a a The b The number that 3 there neither. proportional perimeter p of of an liters is a Justify relationship your relationship, equilateral n of paint of direct proportion, inverse answer. nd triangle needed k with to side paint an length area l. A, given 2 liters will paint a 15 m area. 3 c y = 4x x y = d e y = x 2 3 The variable a Write b Find the c Find f y is in Find 4 5 T is the when inverse y when x when Two variables to their d Write b Mark a of t to are values each of When v = 6, f = 4. proportion. proportionality. x. When x = 5.2, y = 2. to m. When m = 1.8, T = 4. in in inverse this proportion. s 4 t 0.8 table: 4.8 2 Archimedes’ person from the Law of pivot the must Lever be says that inversely the proportional w a function 20 when kg to and Emilie represent is 1.5 sits m 1.25 the from m Law the from of the pivot. the Lever. The pivot. seesaw Use this is information k nd Emilie’s has Sumatran Tiger’ endangered of decided animals. people of Cost person per weight. to which Number Verify relationship v. 3.1. seesaw, Milijenko a variable 2. and weighs Hence, number of the the 1.6. = s down nd constant to solving balanced c m weight a to = missing balance distance = the represents proportional T To v of proportional that proportion Find the inversely value Problem 7 is function inversely Find 6 f 5 encourage funds The cost that the of participating people number her research class and adoption as shown to participate conservation per in person the table in of ‘Adopt these depends a critically on the below: 1 4 8 10 20 $300 $75 $37.50 $30 $15 of people and the cost per person are inversely proportional. b Find the constant c Calculate the cost of proportionality. per person when 25 people participate. 10.3 Getting more done in less time 3 91 8 Conservation number related table of tigers tothe Increase of in US on the wild. in the adoption The program, amount number of spent wild are on tigers trying to double conservation as shown in the is the conservation population Determine whether the proportion. type of Write c Determine goal down of their an how adding 2.4 4.9 8.3 390 624 1274 2158 or not equation much 3 200 this Justify relation your relating will tigers need to the to the is in a proportion, and if so, state answer. two be wild variables. spent to be on conservation met. (This will for the double population.) Determine whether relationships. i 1.5 $) tiger b a the increase spent (millions 9 in like below: Amount a eorts, The the Justify relationship following your relationships are proportional answer. between the distance and the time to see the between the distance and the time to hear lightning ii The relationship the thunder iii The relationship hear b the Lightning i ii iii strikes time km long it takes to see Find how long it takes to hear verify ● What ● How You have ● = seen is a to see the lightning and the time to away. how Hence, kx the Find your does does aect y 5 Dierent C between thunder the answer types it mean to changing to of be one the a lightning. the thunder. iii variation proportional? variable in a proportional relationship other? examples of relationship these of proportional direct proportion relationships: between x and y k ● = is a relationship of inverse proportion between x and y x In the higher next Exploration, powers 3 9 2 of x as you will well. 10 Change see that y can vary, directly or inversely, with N U M B E R ATL Exploration This circle has 3 radius down 1 Write 2 a Find the new area if you double b Find the new area if you triple c Find the new area if you halve d Multiply the e Suggest of 3 new the Justify Write Find 5 This a radius general is or down not of of side the rule and constant what by a the few for area A of the the the circle, in terms of r radius. radius. the more what multiplied area has for radius. r factors, and nd eachtime. statement cube Find a circle the the Write the formula area whether between 4 the r. the the a happens constant formula radius to c, represents of the proportionality the area where a c when ≠ the radius 0. proportional relationship circle. linking area A and radius r. proportionality. length formula happens by to x for the the volume volume if V you the cube. double, of halve x or triple what the side happens multiplied by length. to a the Suggest volume constant c, a general when where c the ≠ rule side for length is 0. x x 6 Justify whether between 7 Write Find Two to a a the or not volume statement the variables power of constant of x x, of and y the and formula the side represents length proportionality of a the linking proportional relationship cube. volume V and side length x. proportionality. are in direct or non-linear proportion if y is proportional . n The variation function is y = kx , k ≠ 0 and n > 0. n y varies directly as Exploration Diego 1 plans Write to down x n or y is in direct proportion to x 4 tile a the wall with formula for square the tiles area A of side of a length square l. tile. t 2 Let A represent the area of the wall. w Let a the number Write down of an tiles = n. expression for n in terms of A and A and l w b Write down an expression for n in terms of A t w Continued on next page 10.3 Getting more done in less time 3 9 3 3 Determine whether proportional 4 State side the 5 Write the the of number area proportional length length to each of the of tiles relationship tile. Find is directly or inversely tile. the between constant the of number of tiles and the proportionality. l down the formula for the area A of this smaller tile. s 6 Find the number m of new tiles he needs to cover Write A down an w expression a in for terms of m: A and A w b in terms of s A and l w 7 Compare n. number b the proportionality you length Does Two and this The that height aect variables proportional tiles x to variation does the and a are function with the to be a whole number of tiles in of of an , tiles you inverse need cover non-linear or . is to and n You > the In varies inversely Exploration 4 as you the smaller ● the number ● the proportionality the problem of tile, tiles Explain what variation = the wall also entirely? if y write is this as 0. y is inversely have more tiles inversely constant found k proportional to x that: you need for proportional changes only to the the when given side the area length initial of each tile conditions of 5 happens to y when x is multiplied by a constant c in these functions: 2 y along change. Exploration ● the is aect: n or should ● the x length proportion can n y side wall? number y tiles 5 has the power to constant? there of changing needed discuss think and of How the Do ● and a Reect ● m kx y = 3 kx y = kx n ● Generalize 3 9 4 your results rst 10 Change for y = kx , n > 0, and then for , n > 0. N U M B E R n ● y = kx is a relationship of direct variation. When x is multiplied by a n constant ● is c, a then y is multiplied relationship of by inverse c variation. When x is multiplied by a n constant Example The light distance a b c the The light Draw a is divided a movie screen is 3 m intensity what distance the on the screen projector Find d intensity the y by c 4 Describe the then between When Find c, the on to to the the the the when varies screen light is represent is the 6 light m intensity and intensity the with the square of on the the variation a intensity is 24 units. away. when the distance between screen is increased by 25%. screen. function. Choose sensible variable names Substitute k = 24 × 9 = the halved. projector light inversely projector. projector, the the screen between eect graph from happens and screen and and the write the known variation values and function. solve for k 216 Find I when d = 6. ⇒ The light intensity at 6 m is 6 units of illumination. b Replace this When the distance is halved, the light intensity is 4 times as d = 1.25d with the d and variation substitute function. great. Increasing 5 c into d d by 25% gives d = n o 1.25d 4 = . 0.64 When 64% or the of distance the is increased by 25% the light intensity is reduced to original. Continued on next page 10.3 Getting more done in less time 3 9 5 d d is the independent illumination variable, I depends as the on the distance. on the curve I 35 ytisnetni 30 25 All 20 thgiL 15 points have meaning, have any as you can 10 distance d on 5 the 0 horizontal axis. d 0 1 2 3 4 5 6 Distance Example The table each a shows of a of Determine cable the is 9 10 11 (m) 1 of four (mm) m if one resistances 1 m cables of the same material, but radius. cable Resistance 8 5 dierent Radius 7 of this of cable (ohms) relationship direct 1 2 5 10 1.5 0.375 0.06 0.015 between variation, the inverse radius variation and or the resistance neither. Justify of the your answer. b Hence, of a the Let R r = As if the relationship = radius variation function, write down the equation increases, R decreases. variation, If , = then Dene k = or r × no pair 2nd k is of pair not values of variables. There is either Compare the constant, k gives so in the variables. R gives values changes variation. For 1st the (ohms) inverse R a (mm) resistance r is function. R = k 1 = × 2 1.5 × = R = , k must be constant. 1.5 0.375 = 0.75 Test with pairs of values from the table. ≠ 2 If R = then k = r × R Try 2 1st pair of values gives k = 1 × 1.5 = 1.5 2 2nd pair of values gives k = 2 × 0.375 = 1.5 Test with pairs of values from the table. 2 3rd pair of values gives k = 5 4th pair of values gives k = 10 × 0.06 = 1.5 2 Therefore, R = , k is which × 0.015 = 1.5 constant. is an inverse b variation relationship, because k is constant. Use 3 9 6 10 Change the value of k from part a N U M B E R Reect discuss ● What conditions ● What do Practice 1 and i For you If each it is think it always means be to met be for direct or variation? ‘proportional’? table a an of values, inverse variation determine variation function, whether function write or down the functions neither. the Justify equation a are a your of the direct variation answer. function. b x 1 2 3 4 x 1 2 3 4 y 1 8 27 64 y 24 12 8 6 d c x 2 0 3 4 y 20 0 45 80 e 2 inverse 3 function, ii must 6 x 2 4 6 12 y 30 15 10 5 f When x 2 0 2 5 x 1 2 4 9 y 0.5 undened 0.5 0.032 y 40 22 13 8 x = 2, y = 12. Find the value of y when x = 4 if: 2 a y varies directly as c y varies inversely 3 x b y varies directly as d y varies inversely x 2 3 y = 24 when x = 5. as x Find the value of x when y = 2 as x if: 3 a y varies directly as c y varies inversely x b y varies directly as d y varies inversely x 2 4 as 3 x The surface area of a sphere varies The surface area of a sphere with directly as the as x square of its radius. 2 a Find b From the c the surface the what enlarged d weight distance the of in Earth. of a factor a sphere above, or 5 with cm is radius otherwise, 100π 2 cm cm. write down the formula for sphere. to the of eect surface area of a sphere when the radius is 5. on the radius of halving the surface area of a sphere. solving an km object from 3670 Find International surface a the approximately of of happens Determine The its area by Problem 5 of information surface State area radius the the km. the Space in A Newtons center of certain weight Station, of varies the Earth. astronaut the which (N) same orbits inversely The weighs astronaut at an with radius 850 when average of N of at the square of the Earth the surface she’s 400 on km is the from the Earth. 10.3 Getting more done in less time 3 97 6 The rings sizes. of of the particle. abundance 7 Under shape with the of its The of If a a a use 2-meter perfect of a low-ow consumption. while low-ow water shower should is be the If a If your the graph Direct an in ounce of 8 a low-ow this an 30 of per shower form per of the size the to per per ounce. volume pipe of 5 our minute This the radius the directly reduce water of in ounce, $40 minute. a of determine varies costs radius with will $24 of variety percent. way liters a cube 10%, a pyrite that the pipe of of the gold) easy liters to of costs pyrite square has tenth cm use only the particles fool’s of 5 become head a of heads use to called piece of abundance nearest length a up proportional an the has may pipe in cm the what head? 6 calculator/software change the a of shower made has to shower proportional of of heads heads be (often side side Regular radius Exploration cost with the regular to inversely particle pyrite shower shower directly head. of is particle, The cube length found size size cube. If water of been abundance conditions, volume. the have the 3-meter right determine 8 Saturn Amazingly, parameters of has the a slider variation bar or similar function and function see how you the can shape of changes. variation functions n Graph the change 1 and graph direct the 3. If and variation value your table of k between calculator of function values 10 has a y = and kx . 10, Insert and split-screen, a the you slider value will be so of that n able you can between to see the simultaneously. 1.1 f1(x): y k*x^n 10 n 1 0. 1. 1. 2. 2. 3. 3. 4. 4. 5. 5. 6. 6. 7. 7. 8. 8. 8 1 k 0. 10 6 1 4 n 10 10 y = kx 2 0 10 8 6 4 2 x 2 4 6 8 10 2 4 9. 9. 10. 10. 6 8 n 10 f1(x): 1 Start with slider, in the the and graph 2 State what 3 Repeat values describe k steps as you k = and and the change represents 1 1 how 2 on for n n the the = = graph 2 1. k x Change changes. value of the value State what of k using does not k graph. and n = 3. Continued 3 9 8 10 Change the change on next page N U M B E R Inverse variation functions This reciprocal includes Graph the inverse variation function graph negative . values of x 1.1 f1(x): k /x^n 10 0. n 1 #U… 8 1. 1 3 k 1. 6 2. 0.5 3. 0.333333 4. 0.25 1 4 k y = 10 10 n 2 x 0 10 8 6 5. 0.2 6. 0.166667 7. 0.142857 x 4 2 4 6 8 10 4 6 8. 0.125 9. 0.111111 8 k f1(x): 10 n x 4 Start with slider, 5 the and values describe k = how 1 and the n = 1. graph Change State what happens as x gets closer to +10 State what happens as x gets closer to 0 the negative 6 Explain 7 Repeat value of k using the and (from 10. the positive side and from side). how steps Reect the changes. the 4 and to proportionality 6 for n = discuss 2 and constant n = aects the graph. 3. 7 n ● Consider ° ° ° ° the variation function y = kx Describe how n aects the shape of the graph. Describe how k aects the shape of the graph. Justify what happens when Justify what happens as positive ● Repeat ● Describe from ● direct a these a the four how negative steps for = 0. becomes extremely large in both the directions. the inverse you can recognize a you can recognize an variation direct function variation . function graph. Describe from and x x how inverse variation function graph. 10.3 Getting more done in less time 3 9 9 Practice 1 Write 4 down the variation a y varies directly as b y varies inversely c y varies directly d y varies inversely e y varies directly x, as as as and x, the as function and y when square the the when and of square cube of = y x, of x, sketch 30, = x 2, x and x, graph. 5. = 6. when and and = its x when when x = x = 4, = 2, y 4, y = y = 120. = 5. 62.5. 1 f y varies inversely as the cube of x, and when x = , y = 4. 2 Problem 2 Determine an inverse solving whether variation a the following function, or graphs neither. show y 3 2 1 variation 3 2 2 1 1 x 0 3 2 1 1 2 2 3 3 3 2 2 1 1 x 1 1 2 3 3 2 0 1 1 1 2 2 3 3 3 3 2 2 1 1 x 1 1 2 the 2 1 1 2 2 3 3 graph of the variation function y . = 2 x a Determine Justify whether your or not y can have a negative value. answer. b Explain what happens to y as x gets extremely c Explain what happens to y as x gets closer d Hence, 4 0 0 3 1 2 3 1 2 3 explain why x x 0 3 3 1 2 Sketch 2 y f 0 3 1 d 3 e 2 x 0 1 1 0 3 function, answer. b y 2 direct your 3 c 3 a Justify this 10 Change is an inverse large. and variation closer to 0. function. N U M B E R Modelling D Until ● Can ● Is now variation situations simpler you or have inverse one change in inverse variation? you favourite each 1 rell Write go will 3 a Suggest a dealing the an coee you a variation there similar shop, can you they are not? functions situations change in in that which, another, are even there either direct though is no a direct or buy equation total cost for as option for you a cup can for either €5 pay and €4.50 rell it for every your time, though €3.50. variation. rule with Are causes which direct when 7 or the Determine not been proportional relationships better? variation. cost down represents 2 to drink, seem always variable Exploration When propor tional it each option relates represents Justify your determining to a and the sketch number direct a of graph drinks variation, and that bought. which one is answers. whether or not a function is a variation function: a b 4 In from its from its Describe but that not a most equation graph. a is situation not an variation of the denitions of technically, it could Exploration 1 Sketch a y = the Explain 3 For and be b why each k practice has been inverse of y they are increases function. problems positive. proportion, k can these the other how you decreases, know it is have be seen so far, according any number to the the except 0, so = are functions: −3x all c variation function, true or functions. determine whether increases, b As x decreases, c As x increases, d As x decreases, e Explain what happens as x gets closer f Explain what happens as x gets farther y y y the following false: x positive y d As the you However, a in as Explain negative. variation statements quantity 8 graphs 3x 2 and constant direct one variation function. examples proportionality where inverse increases decreases decreases increases and negative and closer and to farther 0. away from 0, directions. 10.3 Getting more done in less time 4 01 Reect ● and Summarize discuss your proportionality ● Describe between a ndings. and real-life two 8 What inverse is the dierence between negative proportionality? situation in which there is a negative variation variables. Summary Propor tional ● Two variables are said to relationships be in General direct proportion for values if, and k > shape of the 0 graph k y only if, their ratio is a constant all of < 0 y each variable. 0 k y = x ● y ∝ x means ‘y proportional ● y ∝ x k is means called varies to as x’ or ‘y is 0 x directly x x’. that the directly y = kx for a constant proportionality k, where constant, or k ≠ direct 0. constant linear propor tion of variation. ● The ● Two function y variables = x kx is and called y are a linear inversely variation function proportional k if > 0 k < 0 y multiplying one in variable the other of them by being a non-zero divided by number the same results non-zero 0 k y number. ● If x ‘y and y varies are in an inversely inverse as x’ or linear ‘y is proportion, inversely you can proportional ● If and y is you can inversely proportional ● An of ● write y proportional to Two to say or proportion variables linear propor tion . x, then y is directly x and or y represents a are reciprocal in direct a relationship relationship non-linear proportion k > 0 k y if y is x 0 . equation inverse and ∝ x to inverse x’, = x proportional to a power of x, or < 0 y . n ● The variation function is y = kx , k ≠ 0 and n > 0. 0 n y n ● y varies ● y = directly as x n or y is in direct proportion to = kx 0 x direct non-linear propor tion, n kx is a relationship of direct variation. When x is when n is even n multiplied by a constant c, then y is multiplied by c k > 0 k y < 0 y n y 0 direct = 10 Change 0 non-linear when 4 0 2 kx x n is propor tion, odd x N U M B E R ● Two variables x and y are in an inverse k non-linear > 0 k proportion if y or is . proportional Y ou can also to a write power this of as . variation function is and n > varies inversely as x = n x n or y is inversely proportional to x indirect non-linear when ● is a relationship x x 0. n y 0 k y The 0 , 0 ● < y y of inverse variation. When x n is propor tion, even is k > 0 k < 0 n multiplied by a constant c, then y is divided by c y y k y = n x 0 indirect non-linear when Mixed 1 is propor tion, odd practice Sketch and n x 0 x the graph determine of each whether variation it is a 5 function direct or p is inversely Find inverse the proportional missing values to in the this square of q. table: relationship. p 100 1 x a y = 5x b y = q 3 2 c y = 0.4 2 2 1.4x d y = 6 Write down the function connecting x and y for 2 x each f y = y = values: a 3x x 2 x 1 3 5 8 2.25 6.25 3 3x g of 1 7 e table y = h y = y 0.25 x 2 y 2.5 16 2 5x 5 2 The variable variable a Find t. x is directly When the t value = of 4.6, the proportional x = to the b constant 7 A supermarket £1.30 Write c Find down the function relating t and when t = a P y is = inversely 0.2. Find when y = M varies When M directly = 12.6, as c 1.25 sells 300ml bottles of ketchup for Explain why to y. When P = 15, the = 3. to total the cost of number ketchup of is bottles in of direct ketchup bought. 1.5 b 4 10 8.2 proportional P 5 bottle. proportion 3 4 x a x 0.5 of proportionality. b 1 3.45 square Find c of c. when In a get M = special one oer, if you buy two bottles you free. 17.15 Is the the total cost number of still in bottles direct proportion bought? Justify to your answer. 10.3 Getting more done in less time 4 0 3 Problem 12 solving The with 8 The force needed to break a board varies the length of the board. It takes a force Newtons to break a board 60 cm long. aperture force needed to break a board 20 cm The number of tennis balls you can 125. varies inversely Write down the the relationship can t in a box with the pack variation between and the volume function the radius of of in the A girae’s weight The volume the animal’s varies m tall and weight of height. directly weighs a 2m 1.1 tall An metric baby V base and balls that a the If the the girae During freefall, the an is spent Find proportional falling. how Review An far in it to the of a πr = h is Find object object falls in falls 1 40.8 of m speed cylinder h, the where height cylinder variation b the If the is r When speed when given is of has falls the in a the the xed function write down in this cylinder down square shutter the 4. by the radius of the cylinder. height, between the V write down and r. proportionality case. the andh. has a xed variation Hence, radius, function write write between down the is proportionality directly the 5 girae. distance 8, cube is V 11 is balls. balls. tonnes. inversely setting. expresses of with adult varies 2 constant of camera aperture shutter setting Hence, 10 the a the that number setting Find formula box a the long. 13 9 of of Find aperture the speed square of is 120 the inversely the with shutter constant in this case. time 20 s. minute. context Globalization and sustainability Problem c solving Draw a graph represents 1 In order to reduce overcrowding in their and Alphatown have begun real estate in a way that they hope developers to construct the city Now Boomcity, the with use price of a building plot the distance of the plot from Use the the square of price the of a plot distance varies from both Alphatown the center Find the each city. cost and costs Boomcity, $250 is of of directly diameter a plot 5 the a plot 10 km from the center of be 25 to estimate served by a the number water pipe cm. of the of water that serve ows proportional the 50 pipe. A Make a variation function number water 30 cm, pipe to through the of a square diameter water of 10 the of pipes 40 for of houses cm the of number diameter and 4 0 4 table that diameter with o your number world, so is yet many of trade-os diameter conserve houses that diameter 25 can be cm. estimations of were houses. a priority of humans in many our activities. might pipes want be and and between our using need to water. average of 10 houses cm, 20 50 varies water consumption 25 to can between the per northern served southern hemispheres. But there is cm, great variation between European cm. estimate be widely served cm. 10 Change the by a number water of pipe 80cubic with 5 times 400 Luxembourg’s meters less cubic per than meters average person per Germany’s per person. of year need Discuss cm countries. your far actual the the larger also Use pipe houses. table by water conservation of water and b graph can actual a how the Water head a of km The can number 000. what amount pipe that equation by Discuss parts The the center. g 2 and inversely the from from pipe the f In water center. Alphatown, with your diameter the served In the varies tond city’s of center. e inversely that the served. houses with In function between buildings of outside variation will d encourage the relationship pricing houses oce of cities, diameter Boomcity the is average of N U M B E R Problem Suppose solving with 3 Generating electricity, whether nuclearenergy, on to the fossil can have environment. decrease something the that fuels, We amount will wind serious should of also the construction heating engineer of tries an to negative where it will be with a at X is oce inversely we part a the Find of the distance consume; building, a heater ecient. The If a A, engineer however, position plans the the to put the company’s directly trees 1.5 meters planted. produce change of an 0.3°C. tree change with a that would diameter of 2 be meters. heat heater change what size of 1°C trees was should desired, be used. the Companies use to to a variety buy their of ways to products. try One to of entice those is the setting a price that will encourage people to source. at manager their goods. A clothing company makes position jeans in jeans sell a variety of price ranges. The Bootcut prefers for $25 while the Classic jeans sell for B. Determine how reduce answer varies the heat $160. will a temperature purchase The for determine a in proportional from of temperature expected by square diameter temperature consumers received of money. place most change diameter eects doour 5 spot the average b In of or all energy save temperature cube through Trees hydroelectricity, the the as the a much heat moving received the at X. heater Give to The inversely B your a If percentage. 50 demand proportional 000 bought, were for pairs nd of this to the how company’s the square Bootcut many of jeans of jeans the the is price. were Classic jeans bought. heater b position If the company wanted to double the number B of pairs what of Classic price should be they to jeans should the bought, be nearest sold. determine Your at answer dollar. heater 4 2.5 3 m 6 position A Since the volume of a sphere is by V given πr = , 3 you would should 2 the m of 3 The ‘urban buildings heat and island parking eect’ lots occurs grass and dirt are with normal, in these leading areas to that this, require shade and some tend health the and How you now planting decrease Reect have cities of these the Dave’s and = 5 the cm) the of of a cream of the one Cream price is ice cube price Ice of Shop large radius small (radius scoop of to be issues. have Show that this does not represent a direct trees to variation. higher If this were a direct cube variation, determine To price of one large scoop. ordinances c provide temperature the Suggest to changes. vary reasons based on why the the price volume of does the not ice seem cream. statement of inquiry? Give specic examples. Statement of Inquiry: Changing and to simplied = ice $5.00. discuss explored of scoop constructed, the combat with price concrete. b than at $2.50 (radius cube Temperatures directly the when a covering is that However, cream cm) cream 4 vary scoop. ice think forms can help analyze the eects of consumption conservation. 10.3 Getting more done in less time 4 0 5 11 Equivalence The state of being identically equal to or interchangeable, applied to statements, quantities or expressions 0.999... Did you know that 0.999... = is meaning 0.999… is You prove can not almost this 1, but result is actually using the identical to 1. Read the that following understand each you and will make study sure n Then = in this that = = forever after keeps the step. the show same that decimal rst line from the second way, any is you can innite the same as equivalent . procedure as also repeating its Use gives same 9n numb er chapter. 9.999… the the point. fractional Subtracting decimal, you 0.999… 10n that repeating In Let recurring equivalence decimal transformations a 1? the above to 9 prove 1 that 0.333… is equal to , 3 Dividing both sides by 9 gives or that 0.2424…. is equal to 8 n = 1 (Hint: when two places 33 repeating, the In 1847, Byrne of Englishman published Euclid’s used Elements color theorems, an in Oliver edition where diagrams instead of to text he prove and labels. ● Do of you a think theorem equivalent 4 0 6 to a visual can a ‘proof’ be written one? multiply equation by both 100 are sides instead of of 10). Logical In equivalence mathematics, (or not The ● to Ellie then If Ellie she has has can’t from have are be logically Madagascar crossed not can proved to be equivalent. statements travels she statements logically following If ● be) two the crossed to Iceland equator. the travelled equivalent: equator, from then Madagascar to Iceland. The of second the For rst each statement of the contrapositive logically ● If a ● Ellie on ● If Ellie to ● If passes state whether with its or write not it the is partner. then she speaks will hard then she will do well test. her algebra take her test brother zoo. Ellie’s she contrapositive language. algebra she the the statements, Portuguese studies her then and speaks romance If called following equivalent Ellie is statement. will bus is arrive on at time then school on time. 4 07 A 11.1 model Global of context: Objectives ● Solving linear equations ● Using linear equality Identities Inquiry equations algebraically equivalence equations and and systems linear systems of to MROF Creating a mathematical questions ● What ● How solve using is an equivalence transformation? can you solve equivalence linear equations transformations? equations ● ● relationships F graphically transformations and of and model to solve C real-life Are all solution equations methods for systems of equivalent? problems ● ● Determining if a model solution is equivalent How do the equations the real-life Evaluating and light real-life interpreting your solutions the to of systems the types of of may solutions have? in ● of relate solution they ● graphs to Can good decisions be calculated? problems D ATL Transfer Apply skills and knowledge in unfamiliar situations 11.1 Statement of Inquiry: Modelling with equivalent forms of representation can improve decision making. 14.3 E14.1 4 0 8 A LG E B R A Y ou ● should expand already and factorize expressions to know how algebraic obtain 1 to: Expand: equivalent a 4(x + 3) b 5(2x 1) d 4x(7 + 15 expressions 2 c 2 ● solve linear equations 3 3(8 6x) x x ) Factorize: a 3x + 6 b 5x c 14 + 35x d 34 Solve these 85x equations. x a = 3 b 4x = 52 5 x c 5x 7 = 8 d + 4 = 32 2 ● nd the equation of a line by nding 4 Find the equations of these two lines. its gradient and y-intercept y 4 3 2 1 0 3 2 x 1 2 1 2 3 Linear F You ● What ● How an you solve linear equations using equivalene transformations? know priniples how that is to The examples equations. an use elow Deide priniple’ a 5 = 2 3x = 7 d 6 2x 2x = 11 = 5 linear to do show or ‘the b e h 2 + Lael or 1 = the ‘the – 6x steps you ut 6x = 12 x = 2 4n + 16x 4x stages in the multipliation are the do you know solution = 9n 2 = 5n + + that is 4 1 example the mathematial used 4x = x it’s eing as to solve linear demonstrates ‘the priniple’. f = elow If typially c 2 priniple’. property that think multipliation 6 mathematial 2(3x equations, this? whether g 4x transformation? 1 addition 3x equivalene solve you Exploration 1 equations i either neither = 3 x = 12 7x 1 = 2x 5x = 9 5x = 2x 3x = 9 ‘the of x + then 8 9 addition these, + priniple’ state the used. 4) = 3x + 7 8 = 3x + 7 3x = 15 _________________ x = 5 _________________ _________________ 11.1 A model of equality 4 0 9 Reect ● These an ● priniples don’t solving language formal to terms solve we need linear for an are the 1 alled ‘equivalene transformations’. Why is this name? desrie Equivalence To discuss appropriate Why When and a sutration equations your in the working mathematial priniple past, steps. you In a may this priniples or division have setion, used in priniple? used you solving very will informal learn linear the equations. transformations equation you an use these Principle mathematial priniples: Example An Addition value or Principle: variable Add to the both same sides of Add an get equation. 2x Multiplication Principle: Multiply by 3 to the = both sides equivalent of 2x 3 = 5 to equation uses 8. Multiply both sides of 11 = same non-zero value or variable by both sides of an priniples to transform an equation to get the into an equivalent 5 on mathematial 5x 1 the equivalence transformation equivalent equation. equation. 11 equation = x. 5 Example Solve used the at 1 equation eah step. . Rememer to hek Show your the equivalene transformation solution. Multiply x 2 = 2(3x + x 2 = 6x + 8 2 8 = 6x + 8 x 10 = 6x x 10 = −x + 6x 10 = 5x x − x + both sides by 4. 4) 8 Add Add 8 to both sides (or subtract 8 from both sides). x to both sides (or subtract x from both sides). Multiply both sides by 5. 2 Chek: = x LHS: RHS: LHS 4 10 = RHS ✓ 11 Equivalence A LG E B R A Practice 1 Solve eah a 1 these step. 2x + 3 equations. Rememer = x Show to the hek equivalene your transformation that you use at solutions. − 7 b x 2x 6 1 c −(x + 2) − 3 x = 2( x + 1) d 1 − 3( x + 2) = (2 x − 8) + 3 2 x x 1 e + 2 = x − 4 3 the equals x = equation what Reect and Can you Explain oth think why ● Are ● How system Solving a of an all of and transformations the variale x on to write oth an sides of the the equations every seen how of of an may of two an method you 5( x think + 4) − 8 + this x = 6( x + 2) means. y zero’ is not an equivalene in are do not not equivalene result in transformations? equivalent equations. equations for systems systems of of equations equations relate equivalent? to the types of have? or equations you that methods equation what equation linear is equation why. graphs they the 2 operations of to explain operations solution do algerai and sides these system satisfy have using rakets Explain solutions Y ou with equivalene transformations Systems that use discuss transformation. A 3, happens, ‘Multiplying C (9 − 8 x ) solving equivalene Desrie ● = sign. Apply ● 2x 5 equation equivalent 3 1 h (8 − 4 x ) 4 Problem 4 2 1 (6 x − 3) = 3 For 2x = 5 1 g 2 + 2 f 2 more means the solve equations nding with values the for same eah unknowns. unknown system. an equation (equivalene like 3(x + 2) transformations), 6 ut = 4(2x did you 3) + 1 y know 8 y that you an also solve it using a graphial method? = 3(x + 6 2) 7 (2.2, 6.6) 6 You an onsider the two sides of the equation as two separate linear 5 equations, eah equal to the variale y. You an then graph eah equation 4 onthe same set of axes. 3 Here is a graph of y = 3(x + 2) 2 6 y = 4(2x 3) 1 and y = 4(2x 3) + 1 0 3 2 1 11.1 A model of equality x 1 2 3 411 + 1 The to graph the shows same that value, simultaneouslyis Reect ● Why y x and is the = = value 6.6. So of the x = 2.2 makes solution that oth equations satises oth equal equations 2.2. discuss drawing a graph 3 y hand not the best method to solve this equation? ● When is using solution using You an of an tehnology equation? not an (Hint: appropriate Can you method always nd to nding exat the solutions tehnology?) solve the two equations y = 3(x + 2) 6 and y = 4(2x 3) + 1 algeraially. Expanding y = 3(x y = 4(2x So, we + and 2) have = 3x [2] y = 8x a an ⇒ 1 y ⇒ = y 3x = 8x equations 11 in two unknowns, third equivalene Principle: equation by an transformation Replace par t y = [4] = 8x 11 = 5x [5] x = a Chek [1] the y one value of (x, an use example, value to x into oth here: for the y = 8x of give equations in equations two y 3x RHS: 3 = × pair 2.2 RHS substitution gives unknowns satises oth original [2] 6.6 4 12 two of 3x LHS: single solve. from = equations 11, substitute [1] 8x into equation 11. y = the 6.6. solution is an y). solution LHS The this pair = to − 11 system ordered y, 2.2 Sustituting For and 3x and the [2] 3x you For equivalent expression. [3] x − 11 Substitution of + two y is 6 3) [1] There simplifying: = ✓ method equation 6.6 in equations: x = x − 11 LHS: 3 × 2.2 RHS: 8 × 2.2 LHS redues one two separate unknown. 11 Equivalence = RHS equations in = 6.6 11 = 17.6 11 = 6.6 ✓ two unknowns into A LG E B R A Example Use 7x the + 2y x 2 method = y 19 = of and 4 ⇒ sustitution x y y = = x 4, and to solve hek the your system = x The 4 ⇒ y solution = is 3 4 (3, equations 4 Choose Substitute y of solution. = − the expression for y one into the 2y ⇒ 7(3) + 2( 1) = 21 2 = 19 y ⇒ 3 (− and solve for y. equation, and solve for x the 1) = 4 solution as algebraically an by ordered pair substituting (x, the y). x ✓ and x other equations 1). Check + the Substitute the value for x into one of the equations to nd the value of y 1 Write 7x of y values into both original equations. ✓ y 19 y 7x = 2 3 2 1 y = x 4 Check 0 graphically equations and by graphing nding their the two intersection. x 2 3 4 5 1 (3, 1) 2 3 Practice Solve 1 3x 3 x 5 2x these − 2y = 2 systems = 0 25 + 9 y + 3y = Rupa and and −6 Problem 6 and of y = 6x and equations using the sustitution 7 − 2x − 5y 3x 2 = + 2y 3 = 4 y = 3x 9 − 2x 3x and − 4 y x = + 4y 8 = 11 25 solving George [1] 5x + y [2] x + 3y x + 3(8 and and = 12 − 5y solve this system of equations: 5x Rupa Copy method. = 8 = ⇒ y = omplete = y = 8 and x + 3y = 10 George 8 5x 10 5x) + [1] 5x + y [2] x + 3y 10 their working 5(10 to nd their = 8 = 10 3y) ⇒ + y x = = 10 3y 8 solutions. 11.1 A model of equality 4 13 Reect ● ● Does and your nal variale you Pratie 2, When is discuss solution hoose to question it easier Exploration to 4 for the solve system for and of equations sustitute? depend Hint: look on whih ak at 6 sustitute i for x ii for y? 2 Tip 1 Find a solution for the following system of equations: If x + y = the question 4 doesn’t 2x y = 5 whih to 2 Write the equations one aove the other (as aove) and then add one term at a you Explain 4 Find 5 Starting x + what the value with y = 4 y = 5 2x multiply 6 Rewrite this Add the 8 as the time. new the the to either system in the this original the in y’s in new the equation. algerai graphial or method. equation. system, rst equation did step equations value Sometimes another to from term you two x either equation and the y seond 2. equation diretly aove one 2 together term y term. Explain what happens to x’s. Find solve of the eah another, 7 happens an them the 3 you method use, hoose together, tell for x or that equations [1] 3y x = −3 [2] y x = 1 Sutrating [2] y from sustitution method of of from y, or uses 3y [1] this method eause the x new = ideas −3 an e a it equations from and eliminates equation. y the x triky, with Exploration = eause frations 2. it is result. Let’s use it diult There to is solve the 1: variale x Tip 3y x = −3 x = 1 Reall y that sutration 2y = −4 y = −2 Sustituting system of y = addition −2 into equations 414 of opposite. is ( either 3, [1] or 2). 11 Equivalence [2] gives x = −3. The solution to this is the the A LG E B R A Cheking the (1) = y x 2 This Can see solve sutrat touse 1 3 is 1 original equations: an x 3( alled the elimination method = 2) for −3 ( 3) solving = −6 + 3 systems = of −3 ✓ equations. why? of equations equations equivalene to using eliminate the one transformation elimination of on the one method, variales. or oth You add may equations or need rst. 3 system your 3y ✓ systems eah Chek = the Practice Solve oth (2) 3) method To in 1: ( you solution of equations solutions [1] 5x + y = 27 [2] 2x + y = 12 [1] 2x [2] 2x 3y + y Reect = = using algeraially or the elimination 2 −16 4 0 and discuss How do you deide whih ● How do you deide what a Exploration [1] 2y [2] 4y [1] 3x [2] 5x x = 7 + x = 11 + 2y = 11 2y = 13 5 ● toeliminate method. graphially. variale to to multiply eliminate? one of the equations y in order variale? As 3 early the In Pratie 2, you solved the following system of equations y as 3x + + 3y 2y = = −6 solving of two the if it is equations Determine system possile y an to eliminate integer and a then variale adding. y multiplying just one Explain. unknowns. method in the if it is possile to eliminate x y multiplying eah equation is in dierent integer and then adding. Jiuzhang (Nine y in the Explain. Mathematial 3 Solve the system y eliminating 4 Solve the system y using 5 Chek 6 Explain your answer how you y similar sustituting would deide Art), x written a The desried ook Chapters a a equations suanshu 2 method 25 Determine of a of two 1 bc had sustitution: invented 2x 200 Chinese method it into whih to eliminate oth variale of to the y instead. original eliminate Han during the Dynasty. equations. rst. 11.1 A model of equality 4 15 Example Solve the 3 system elimination of equations method. [1] 5x 7y = 27 [2] 3x 4y = 16 Chek 5x your 7y = 27 result and 3x 16 algeraially = or 4y, using the graphially. Rearrange the equations Choose Multiply oth sides of [1] y 4, and oth sides of [2] y 7. that to line equivalence give the same up like terms. transformations coecient for one variable. [3] 20x [4] 21x 5(4) 7y + = 28y = 108 28y = −112 x = −4 ⇒ x = 4 Add Substitute into to value one [3] of and the [4] to eliminate original y equations 27 nd 20 7y = 27 7y = 7 y = −1 is (4, Solution nd the Write 1) the of the 2 solution variable. as an ordered pair. Check algebraically by substituting the 5(4) 7( 1) = 20 + 7 = 27 ✓ solution into both original equations. 3(4) 4( 1) = 12 + 4 = 16 ✓ y 2 3x y 1 16 = 4 0 Check x 2 5 6 graphically to nd 7 1 (4, point 1) 2 5x 3 y 27 = 7 4 Practice Solve eah Chek 1 2x 3 x + system your + 5y 3y 4 of answers = 24 7 = and 0 equations either 4x and 2y x 5 3x = 17 + y and 3y x the = = 20 3 elimination or method. graphially. 2 2a 4 5r 6 4x + = 3b = 23 −9 3s and and 4a 4s + = b = 12 13 2r y + 5 4 16 + using algeraially = 0 2 11 Equivalence 0.5y = 12.5 and 3x = 8.2 0.8y of intersection. the A LG E B R A Reect ● and Would it systems ● When a Practice Use the 1 3x 3 3y 5 4x + + system y 9 and 2x = 11 3y = −2 Draw the a + x 4x 2 of eient you 5x and and of linear use the 4? linear sustitution If so, explain equations, Write yourself equations algerai + y 4y + how a set method on any of the why. do of you selet guidelines the on most how to eiently. your method hosen for solving method eah eah system time. of Chek equations. your graphially. = 2x 4x 22 = y = 9 6 2 y = 2x + 4 and 3x + y 4 3x + 2y = 16 and 7x 6 3x + 2y = 19 and x = + + 9 y y = = 19 8 4 2y = 16 8y = −64 the or systems Generalize down to Pratie method? seleted Exploration 1 system algeraially = in 5 why solutions a 6 eient algerai most Explain more equations solving eient solve e of discuss of equations on separate b your x graphs: + 4x results onditions from your neessary work for a so 2y = 16 8y = 24 far, system of and two from step linear 1. Write equations to have: 3 ● a ● no ● a unique non-unique Desrie Without reasons, a 2x x c + how 6 5 2y = 0 + in or 5 2y = −10 it is not unique why any of not (an of innite systems Inlude these the a numer of sketh has of a for for a relate eah 2x + system of state, and 3y = 12 3y = 6 two the numer of ase. equations, solution, to giving explain linear why. equations to solutions. you the possile solutions). equations systems system of 2x = two Explain not pair) b y why have. solving whether = graphs may atually y Explain have ordered solution the they 2x 4x 5 (an solution solutions 4 solution should test equivalent your solution equations you in the get original from equations, using and equivalene transformations. 11.1 A model of equality 4 17 Applications D ● You are Can going 80questions. ● eah good to take The orret of deisions a written soring answer is e 1 of equations alulated? driver’s suh sores systems liense exam that ontains that: point 1 ● eah inorret answer is a point dedution. 4 If you order Step answer to 1: earn all 70 of the points Identify the questions, (the how minimum x represent the numer of orret Let y represent the numer of inorret 2: Identify do you need to get orret in pass)? variables: Let Step many to the answers. answers. constraints: Conditions Both x and negative y must numer e of positive numers or zero, sine you annot answer a the questions. values variales on of are the alled onstraints. There are 80 Expressed Step 3: Write The questions, the mathematially: Create the equations 80 so to questions numer of 0 maximum ≤ x ≤ 80; 0 for ≤ y x ≤ or for y is 80. 80 model: represent are orret orret the or answers situation. inorret, + numer so: of inorret answers = 80 ⇒ x + y = 80 1 Total sore = (numer of orret × answers) (numer of inorret answers) = 70 4 1 ⇒ x y = 70 4 The model [1] x [2] x + is y = a system of two equations: 80 1 y = 70 4 Solve your model: Finish Use an eient method to solve the system of out Check your working equations. and solution: the prolem then answers Chek your solution algeraially, or y using a GDC or graphing in software. sentene. Interpret To earn answer your 70 solution points, you questions 4 18 in the need to context answer inorretly. 11 Equivalence of the problem: questions orretly, and you an ll in the the last A LG E B R A Example From an the in 1996 e 4 to 2012, modelled total exports years. The or year y = 1310x Imports: y = 725x analyzing imports 0 and x = x (from y represents the the imports + + 1996 in and system millions represented exports of of y from equations, dollars, x = and a partiular where x y ompany represents represents the time 0. 7430 of equations, etween year 2012) the is system the to imports 5165 exports represents total following 2000 Exports: By the y total 1996 2000, is 4 ≤ exports so x ≤ or desrie and the the ompany’s pattern of 2012. range of Identify the variables and constraints. 12. imports, thus y > 0. 16000 14000 12000 Graph Imports: the system of equations. 10000 (3.87, 10 237) y = 725x + 7430 The 8000 intersection which 6000 is around is at the x = year 3.87 ≈ 4, 2004. Exports: 4000 y = 1310x + 5165 2000 0 3 4 The it ompany spent the more had on ompany’s Practice 2 1 no 1 exports imports export 2 in than inome it 3 4 1996. made 5 6 Then, on exeeded 7 8 until exports. its 9 aout After import 10 11 Interpret 2004, the 2004 in expenses. the graph the in information your context of own the from words, and problem. 6 ATL Problem In the following answer of 1 the You your prolems, question. equations, open running and a for your Between x Coal = and Petroleum Calulate the y oal e the = in the given eient how the and year y whih initial $7800. mathematial method = investment The long amount y the weekly will you petroleum modeled 93.2x prodution: year an are mathes an represents use Determine 2010, prodution: with usiness prot or most for model solving the to system solution. usiness the ountries 0 the your $8800. total 2000 produing where is reate Choose hek small osts usiness (when 2 solving it of $90 000. revenue e have efore weekly you reak from even invested). prodution following The (inome) from system the of fuel- equations, 2005: + 3100 −29.1x + prodution 2942 from oth forms of fuel was equal. 11.1 A model of equality 4 19 3 A phone ompany operating fee of $5.20, whih 4 You fee plan gave fund muh of Why interest 5 to est an 15.5 per for interest the year discuss of minute. you, hoose explain roker, and the rest how in a into Plan B you A harges harges would an an operating deide on reasoning. put $210 plaed Plan your who reeive was from. minute. part fund in of the paying interest. eah money 5% in a annual Determine how fund. 7 want oers to per Determine and you investment them plans ents investment annual of weekly plus someone of kind two ents e end and one What 37 initial would when ● 2% the your Reect ● plus $4500 At has $31.45, would paying interest. of a advantages to plae lower might their return the money than ank the oer in two other in the dierent funds, one? fund with the lower rate? Your unle week (2 kg Karl wants to lose some weight y urning extra alories eah iyle, whih During = approx. 3000 alories). He will do it y riding a de urns 350 alories an hour, and y walking, whih urns 200 hour. If unle Karl has 10 hours per week to devote to exerise, ylist of walking and yling will allow him to ahieve his goal exatly 3000 etween of 4000 urning will what urn omination Tour rae, alories a an the Frane and 5000 alories? alories That 123 for is per 900 the stage. around alories entire ATL Reect and discuss 8 rae, to ● Is it possile to reate more than one orret mathematial model equivalent 252 doule to heeseurgers. solve a partiular ● Are ● Explain all methods in onepts your of prolem? for solving own equality the words and model the equal similarities or and equivalent? dierenes etween the equivalene. Summary 1 An equivalence appliation priniples of in transformation one or solving more an of is the equation the 2 following so that Methods of solution equations are Priniple: values oth to sides Multipliation same an non-zero Adding of an Priniple: value or the same value or equation. Multiplying values on one y oth the sides of Elimination: of to Priniple: 4 20 an Replaing equivalent part expression. of 11 Equivalence the in of the By one equation this and other one two linear equations in redue one value sustitute equation, this resulting unknown. applying transformation(s), equivalene the two unknown, into one of equations and the solve. original an equations y one variales, into equation Sustitute equation Solve the expression one equation. Sustitution of equivalent: for Addition systems all Sustitution: resulting for equations: to solve for the other variale. in A LG E B R A Graphial: enter the software. solution Solve oth equations The of point the equations into of a GDC for or y and the graphing intersetion is the lines Solution are of equations.The are oinident, atually the graphs whih same of the means the two line. system. 4 3 system equations senarios for a system of two linear Creating of a mathematial model using systems equations: equations: One solution: system graphs No of of the oth equations Innitely numer Mixed 1 Solve There an is no parallel to pair. interset ordered The Identify ● Translate the system equations pairs these at one 3x b 4 − 3x of that equations the ● Solve two ● Chek that is will an ● innite system the of prolem into a equations solution the real-world satisfy y identifying you the use 2 at + 4 Use = 19 = a 5x either eah of − 1) = in the solution original in the ontext of the prolem 4 (2 x − 3) elimination system method. y = x b − 3 x + 2 = 4 − 4 x of Chek + 3 − 7y and = 19 or sustitution equations. your y and = solutions − x 5x Justify to your solve hoie graphially. − 2 − 8 y = −13 1 x c + y = 1 and x − y = 3 6 1 x d 3 1 x + 1 y = − 1 and 5 x − 11 y = 2 3 e Objective: solve the ecient A. solution in for that a variety describes of each systems of real-world problem, instead of A taking you y vitamin An and of will get drinking your milk and the this oune of milk ontains 56 μg (mirograms) of orange juie ontains 5 60 μg of vitamin A. μg a of many ounes need A realisti hemist −33 to of drink milk daily and in requirement of amount Deide for whether you to or not drink. has een asked to make a solution of liters mg has ontaining only two 20% aidi aid. The solutions, prolem one is that ontaining of aid and the other ontaining 32% aid. Determine orange order 550 A. vitaminA; to juie meet mg of how many liters of eah he should you in order to reate the solution he has een your asked minimum = 38mg use would − 7.5 y most vitamin Determine how − 1.5 x and 12% alium select 1200 he oune and 16 equations. 8 ofalium = 17 6 relationships vitamin juie. + 2.5 y 6 ontexts 2 orange 3.5 x 4 understanding in solving supplements and 2 context that mineral alium model method and deide and orretly mathematical Identities You Knowing prolems Review an real-life 1 d and the Interpret 4 1 of equations There transformations 2 For onstraints will 1 iii. and point. step: 3(3 x variales practice a c the The pair graphs ● the lines. solutions: ordered solution ordered will equations. many of is equations are equivalene eah algerai equations solution: satisfy The alium to make. and 11.1 A model of equality 4 21 3 A oee The distriutor premium kilogram, $8.25 these and 20 kilograms lends Determine should e is in the ommodity, Sine Brazil oee, oee In the 1991, pot, they a a the it is Before of you have oee. 4 per sells most y for wishes to in has lend on live in of the fator 1.5 printer, an is (e.g. the with world’s in University on world sientists the we or not. oee so that This weam. US in the Amerians 1700s, was the eer. discuss explored the statement equivalent forms making. 4 2 2 the etter of inquiry? Give spei examples. Statement of Inquiry: Modelling ost 11 Equivalence of representation an improve deision a printer two ut whih average onditions uy to ents. traded department’s empty the of valuale $150 Brazil. their was drink just inkjet 40 % footage rst page is to down osts ontaining eah it printer kilogram. of deided narrowed petroleum. inuential on You’ve printer only pot aught How per kilograms around live reakfast and $9 Camridge the Reect lend mixture at weather world’s oee preferred of $10.50 distriutor seond most the if types for mixture. amera tell a many the group the of sell produes streaming made The surpassed xed ould to world’s single pries aimed how two sells standard kilogram. two Coee the per reate has lend laser average ost of The osts 6 other $30, ents. numer uy. have The the of and hoies. of option ut is eah eah an page Determine pages) the where eah More than one way to 11.2 solve Global a problem context: Objectives ● Solving Scientic and Inquiry quadratic equations algebraically technical innovation questions ● What ● How is the null factor law? F and ● graphically Solving using problems quadratic by creating in do you factorized solve a quadratic equation form? models ● How can you use MROF and real-life equivalence C transformations to solve quadratic equations? ● How are the quadratic ● How do three methods equations you for solving equivalent? determine a ‘best method’ D among ● Do equivalent systems, problems ATL or methods? models create and methods solve them? Critical-thinking Propose and evaluate a variety of solutions 8.2 9.2 Statement of Inquiry: Representing patterns with equivalent forms 11.2 can lead to better systems, models and methods. 4 23 Y ou ● should conver t into already quadratic standard know how 1 expressions to: Rearrange a form (x + into 2)(3x standard form: 1) 2 b ● conver t quadratic expressions into 2 (x 1) 16 Factorize: 2 factorized form a x + x 6 2 b 2x + 5x 3 2 c 4x 81 2 ● conver t ver tex quadratic functions into 3 Write form in where the (h, k) form is y the = a(x h) + k, ver tex. 2 a y = x 6x + 14 2 b ● use in equivalence solving linear transformations 4 y = 3x 6x + Solve 3(x + 2) equations 7 6 = 4(2x 3) + 1. State the equivalence transformation you use in each step. Quadratic F Th ● What ● How graph is do shows th null you th and fator solv two linear a linar equations law? quadrati funtions quation f (x) = x in + 1 fatorizd and 1 and th f = (x) funtion (x + 1)(2 whih is th produt of f (x) = form? 2 x, 2 ths two linar funtions, x). 3 y 7 6 f 5 (x) = x + 1 1 4 3 2 f (x) = 3 f (x)· f 1 (x) 2 0 7 6 5 4 3 2 1 x 3 1 2 f (x) = 2 x 2 3 4 5 Expanding 6 (x 7 + 1)(2 givs Th graph baus f of (x) th = (x produt of th two + x) is quadrati 1)(2 a 3 4 24 11 Equivalence linar funtions funtion. is a parabola, a x) quadrati xprssion. A LG E B R A Exploration 1 Writ ths a = 1 quadrati funtions as th produt 2 f (x) f (x) = 2 Graph 3 Writ two linar funtions: 2 + x 3x + 2 b f (x) = −x x d f (x) = −3x 2 c of + 2 2 2x 5x ah 3 quadrati funtion with its + two 4x 1 rlatd linar funtions. 2 th Graph th Reect ● What funtion ● is Whih bing Th zros rosss th a th nd funtion of up So, th Exploration 4x or th btwn of linar th nd 1 as its a produt two rlatd of two linar linar fators. funtions. 1 onav ar to + and x-intrpts funtion x-axis. to 2x rlationship and paramtr of = discuss onav th yound quadrati and funtions f (x) x-intrpts of th original linar parabola? funtions is rsponsibl for th parabola down? x-oordinats th x-valu(s) th th x-intrpts suh that f (x) of th of any = points whr funtion th graph algbraially, 0. 2 2 1 a Plot th graph b Fatoriz of f (x) = x + 2x 3, and nd th zros of this funtion. 2 produt c Solv d Chk x is g (x) + = your vrifying 2x 3 to nd two linar funtions g and h whos f (x). 0 and h (x) solutions that thy = 0. algbraially satisfy f (x) = by substituting thm into f (x) and 0. 2 2 Plot 3 Explain th You For th two = of th at of th f (x) or = 3x 4 law last g (x) h (x) fator = a × 0, of and or 0 and if th to that th b, h (x), and law stats on = btwn funtion null numbrs 0 x rlationship factor thn Whn g (x) us null zro, graph zros an Th th th th whr = g 0 produt must thn and of quadrati numbrs ab parts solutions solutions solv if rpat h a = ar of b 0 a of th to d th in stp linar quadrati 1 quations, quation. quations. two or mor numbrs is zro. or b = 0, funtions, or if both. f (x) = 0 thn both. 11.2 More than one way to solve a problem 4 25 Example 1 2 Solv 2x 6x = 0. 2 6x 2x 2x = x 0 3 = x = ⇒ = 0; 0 x ⇒ = ⇒ x 1 0 = 2x (x 3) = 0 Factorize 0 x Use = the the quadratic. null factor law. 3 3 2 x = 0: 2(0) = 3: 2(3) 6(0) = 0, LHS = RHS ✓ Check both solutions in the original equation. 1 2 x 6(3) = 0, LHS = RHS ✓ 2 Example 2 2 Solv (2x 2x + + 2x 5x 1)(x 1 = 3) 0; x 3 = 0 3 = = 0. Factorize the quadratic. 0 Set x = both Check ✓ linear the functions solutions in equal the to 0 original and solve. quadratic. 1 2 x = 3: 2(3) 5(3) 3 = 0 ✓ 2 Practice 1 Solv 1 ah quation, laving your answrs xat. Tip 2 a 2 x 8x = 0 b 2 x 5x + 6 = 0 c 6x + 4x 16 = 0 To 2 d 2 x 9x = 0 e 4x = 1 2 g 10 3x = f 3x 2 x h x = us fator 2 48 = 2 i 9x = 10x 2 4 = Problem 2 Writ a 23 k 13 2x 2 = 5 l 18 quation in standard form that has 2 and 4 6 c a quadrati quation with roots and 4 a whos b with 4 2 6 lading only oint intgr and 5 3 Find + 2 and b 2 3 9x solutions: 1 a = solving quadrati is 1 oints. 11 Equivalence rst rarrang th quadrati so 2 6x 2 3x null 0 qual j th law, 5: 3 2x to it zro. is A LG E B R A You hav now Howmany sn quadrati solutions Reect and an quations quadrati discuss Graph ● Explain ● Can a f (x) = two uniqu solutions. hav? 2 2x why hav 2 2 ● that quations 6x thy quadrati and hav a g (x) = 4x dirnt quation hav 4x + 1. numbr of mor than uniqu two solutions. uniqu solutions? Explain. Practice 1 Solv 2 ah quation, if possibl, 2 a + 2x + 1 = 0 answrs xat, x 6x e 4x + 9 = 0 c x 2 9x 6x + Problem Writ a 1 = 0 10x x = 3 s.f. = −25 9 = 12x f 9x = −4 12x solving quadrati quation −2 in x b standard form whos only solution is 3 = c x = 5 Example to 2 + 1 a or 2 b 2 2 your 2 x d laving 4 3 2 Th lngth a Writ b Solv c a Writ Lt A x = of an a rtangl quation th th width. x(x + that 4 m mor rprsnts than th its ara width. A of Its th ara is 21 m . rtangl. quation. down = is 4) = dimnsions Thn lngth of = th x + rtangl. 4. State your variables and write the equation. 21 2 b + 4x x + 4x (x + 7)(x x = Rearrange, 21 factorize, and solve. 2 x + 7 = 21 = 3) 0 ⇒ 0 = x 0 = −7 = 3 1 x 3 = 0 ⇒ x 2 x c width = 3 m, lngth = width + 4 m = 7 is a length and cannot be negative m hence x is not a solution. 1 Practice 1 Th 3 width of a rtangl is 3 m lss than its lngth. Th ara of th 2 rtangl 2 Th is lngth 18 of m a . Find rtangl th is 1 lngth m and lss width than 2 of th tims its rtangl. width. Its ara is 2 45m . Find its dimnsions. 11.2 More than one way to solve a problem 4 27 3 A rtangular shapd gardn’s lngth is 2 m lss than twi its width. 2 If th ara of th gardn is 420 m , nd th dimnsions of th gardn. 2 4 Th th bas bas of a and hight Problem 5 A 5 squar m th xds of th its hight by 17 m. If its ara is 55 m , nd triangl. solving and mor rtangl of triangl a rtangl than is 6 twi m lss hav th th lngth than th sam of sid th of ara. sid th Th of th squar. lngth of squar. Find th th Th rtangl width lngth of of th is th sid squar. 4x x 6 Find 7 A th pol hight th lngths lans of wall. 15 of th against m. Find Th th ● How of vrtial lngth of distan Solving C a sids this wall. th from triangl. Th pol th you us is 1 wall quadratic an top of m to th pol mor th touhs than bottom twi of th th its wall at distan a from pol. 3x equations quivaln transformations to solv quadrati quations? ● How ar th thr mthods for solving quadrati quations quivalnt? ATL Reect You Do hav you What and sn think would discuss that it its is quadrati possibl graph Exploration 3 quations for look a an quadrati hav on quation or to two hav solutions. no solutions? lik? 3 2 1 Using a GDC a Find th b Construt or graphing points lins whr softwar, th through graph parabola th th funtion intrsts intrstion points th f (x) = x 2x 3. x-axis. that ar paralll to th y-axis. c Grab what its d th parabola happns vrtx Th vrtx happns th is of to x-axis, to to th th th and and th mov two lft and original vrtial whn it th around lins right parabola lins is it vrtial as you xatly of is th as th th mov plan. th urv Dsrib so that y-axis. blow mov on oordinat you th th x-axis. vrtx so Dsrib that it is what abov x-axis. 2 2 Graph th funtion f (x) = 3 + 2x x . Rpat parts a to d in stp Continued 4 2 8 11 Equivalence 1 on next page + 3 3 A LG E B R A 3 Basd a on your whthr linar b or abov th not a to stps 1 and 2, dtrmin: quadrati funtion is always quadrati funtion has th produt of two funtions. whthr c answrs or or not a blow numbr of th zros if th funtion is always x-axis. zros of th quadrati, if its vrtx lis on th x-axis. ATL Reect and discuss 4 2 f (x) = x 2 annot b fatorizd using only intgrs. 2 ● Solv th quadrati dirn of two quation x 2 = 0 by fatorizing 2 = 0 by rst using th squars. 2 ● Solv th quadrati quation x using th addition prinipl. ● Do your two mthods giv th sam solution? 2 Whn a quadrati is of th form ax c = 0, c > 0, you an us th addition 2 prinipl . Taking to Th th rarrang solution squar to ax = c, is root and th multipliation sids is quation. of lavs not an 1, and Disuss x = both sids = th 2x xampl whih quivaln Reect ● 1 For to gt . of an quation 2 quivalnt prinipl is ( 1) obviously dos not always giv an 2 = 1 , fals. but taking Thrfor th squar ‘taking root th of squar both root’ transformation. discuss rasons for 5 ah stp in solving this quation. + 3 2 [1] x = 2x + 3 2 [2] x 2x [3] (x 3)(x [4] x [5] x 3 = 3 = 3, 0 x 1 ● Is Whn a intgr fators. quadrati th + 0 1 = 0 −1 of sids’ funtion oints, omplting = x both quation Instad 1) or = 0 2 ‘squaring quadrati + = has it an an quivaln b solutions. may b writtn Whn diult fatorizing, to anothr as transformation? th produt quadratis xprss mthod do thm for of not as linar hav th solving Explain. fators, fators produt quadrati of th with linar quations is squar. 11.2 More than one way to solve a problem 4 2 9 Example 4 2 Solv x 2x 4 = 0. 2 x 2x 4 is 2x 4 = not fatorizabl. 2 x 0 ‘Complete the square’ to write 2 x 2x = 4 x 2x + 1 (x 1) the quadratic in vertex form. 2 = 4 + 1 Take the square root of both sides. Don’t 2 = 5 forget the positive and negative Check the both original square roots. solutions in equation. ✓ ✓ Example 5 2 Solv th quadrati quation 2x 4x 3. Rationaliz th dnominator in your answr. 2 4x 2x Rearrange 3 the equation and factorize 2 so that x has coecient 1. 2 2(x 2x) 3 Complete the square. Solve 4 3 0 11 Equivalence for x. A LG E B R A Practice Solv, if 4 possibl, by omplting 2 1 x 4 x 7 x = −1 Lav your answrs 2x + 2 x + 5 x 8 2x 2x = 1 4x + 6 3 x 6 x 9 3x 2 = 0 2x 20x + 40 = 0 2 0 Whn a 20x + 3 = 0 quadrati ‘omplting ‘quadrati qual th 11 quation squar’ formula’. to zro to Just bfor 4x + = 4x annot using 0 + 6x + 1 = 0 1 + 6x = + 12x 2 2 4x solv lik = 2 + 2 + 2x 2 2 = 2 + xat. 2 2 2 st squar. 2 4x 2 10 th it. with th = b 3 12 fatorizd, You an also fatorizd you us form, 2x an a th us = th mthod −9 mthod that quation of involvs should th rst b formula. 2 Th quadrati Example formula to solv ax + bx + c = 0, a ≠ 0, is . 6 2 Solv x + 3x 1 = 0, giving your solutions to 1 d.p. Write a = 1, b = 3, c = the quadratic formula and the values the values into the formula Separate 1 Solv for answrs 4p th variabl, xat. if possibl, Rmmbr to st 8p 1 = 0 b q g 9x 2q = − 5 e + if Chk 11 = 6x h possibl, your th solutions x d 5a 3a = 4b qual formula, to 0, using a x 3 = 0 b 2 + 1 = 0 c − 6c + 3 f 4b 8 = 1 quations GDC or i giving graphing two solutions. 3a + 1 = 0 e your nssary. r + 3r 6 = 0 2m + 23 + 8 = 14m your 4t = answrs −t to 1 d.p. softwar. 2 x 2x 4 = 0 c 2 + laving whn 2 + c simplify. 2 + quadrati 2 a quadrati 2 Solv, the and 2 3c 2 2 th quation 2 + and 2 5a 2 d using th 2 + b 5 2 a a, −1 Substitute Practice of r 4p + 8p 1 = 0 2 + 3r 6 = 0 f x + 4x + 7 = 0 11.2 More than one way to solve a problem 4 31 3 Solv ths quadrati quations 2 a giving your answrs in radial 2 = x x + 5 b form. Tip 2 x + 5x = + 6z 1 c 2x x = 1 For 2 d 7x = 3 e 2z = Solv, giving your 0.6x 2.6 answr to 3 x 2 + = 0 b 3.2 + x 1 Crat rst a = tabl two quation, (if if 0 e as th 3x 2.2x sam shown possibl, possibl), th sid is right so hand + 0.3 = 0 c 4 2x 3x = qual to 0. 0 = 3x + 1.1 4 with rows that 2 1.2x Exploration rarrang 2 0.2x 2 d 3, s.f. 2 a quations −95 in 4 th 2 x olumn hr, using omplting thn on th hadings ntr mthod squar, or th from th as six th on blow, quations th thr quadrati blow and in quivalnt formula. In giv th it rst solution th 8 rows. Copy olumn. Solv mthods: fourth olumn, th ah fatorization substitut th 2 paramtrs a, b and c of th quadrati 2 into b 4ac 2 2x + 5x 3 = 0 2 x 2 + 4x 4 = 0 2x 2 x + 2x 2 = 0 + x + 1 = 0 2 3x + 4x + 1 = 0 2x 6x + 5 = 0 Sketch Can of the Number graphical quadratic 2 Equation Solutions of distinct b 4ac solution be solutions (include x-axis, factorized? but 2 + 2x + 1 = 0 x = −1; x 1 = −1 1 2 4(2)(1) = 1 Yes 2 2 x Us y-axis) 2 x 2 not 2 + th 1 = 0 answrs No in solutions your tabl to 0 omplt 0 ths 4(1)(1) = − 4 No sntns. 2 a Whn b b Whn b c Whn b 4ac = 0, th quadrati quation has _____ distint solution(s). 4ac > 0, th quadrati quation has _____ distint solution(s). 4ac < 0, th quadrati quation has _____ distint solution(s). 2 2 3 Stat at how many points th quadrati xprssion intrsts th x-axiswhn: b 2 4ac = may look bak nd at quadratis 2 a You 0 b ar 2 b 4ac > 0 c b 4ac < to othr that fatorizabl 0 in Prati 1 and 2 4 Explain a how quadrati 4 32 th xprssion xprssion an b b 11 Equivalence 4ac hlps fatorizd. you dtrmin whthr or not 2 valuat b 4ac A LG E B R A 2 Th part and th of th quadrati symbol w us formula, for it is b th 4ac, Grk is alld lttr th dlta Δ. discriminant, W writ 2 Δ = In b 4ac 820 th ce, mathmatiian quadrati Europ around by today By for Mohammad positiv mathmatiian In 1545 quations. Practice 1 th 1100. quadrati know formula in Rn onsidring th ii whthr th numbr or of disriminant distint not th quadrati 3x + 2 = 0 b + 7 = rst Géométrie in of ah x is of th th you 4 e valus of k suh + 16 + 8x + = 0 (1 form on w stat: quation fatorizabl. 7x + 6 = 4x 28x + 0 40 that th c = quadrati solution) 3x + 17x 2 = 3 0 has th givn numbr of solutions. b 3x ● How ● Do solving did or + kx + 12 = 0 (1 solution) 2 k = 0 (2 Solutions squar, th solving kx 4x Whn in Spain work 2 + D in 1637. quadrati 2 c livd xisting appard quadrati, 2 a th to 2 −5x Problem Find who drivd brought 2 x 2 2 Hiyya, was 2 2x 3x Al-Khwarismi mthod ompild formula solutions 2 d La His bar Cardano quadrati Dsarts’ Musa 6 i a Abraham Girolamo Th bin solutions. do systms, quadrati whih th you of th quadrati solutions) of d kx quadratic dtrmin modls and quations, thr a ‘bst formula) is th solv for solution bst + 5 = 0 (no solutions) equations partiularly of 3x mthod’ mthods mthods + among quivalnt problms ral-lif or mthods? rat problms, (fatorizing, thm? how omplting do th mthod? ATL Reect and discuss ● of thr Whih If this ● How ● Whih your th mthod ould did you mthod solutions mthods not nd 2 work, out would to 6 if you would whih th try dimal you quation rst if plas? try rst? mthod is th Explain would you why. try nxt? fatorizabl? qustion Explain askd you to giv why. 11.2 More than one way to solve a problem 4 3 3 Example 7 2 A gardnr has 16 m of fning to stion o a rtangular ara of 15 m . Tip Dtrmin th dimnsions of onstraints th on th dimnsions of th rtangl, and nd th rtangl. ‘Dtrmin onstraints’ Primtr = 2(lngth + width) = lngth Lt + width width = x. = 8 Thn for lngth = 8 1: x > ⇒ 0 < Ara x = < 2: th inquality valus’. and width can be only positive values. 0 Write Constraint an x. Length Constraint mans 16 ‘writ ⇒ th 8 x > 0, so x < inequality statements to reect this. 8 8 x(8 x) = 15 2 x = 15 8x + 15 8x Calculate the discriminant to see 2 x = 0 if Hr, a = 1, b = −8 2 ⇒ and c = 4ac = ( The 8) − (4 × 1 equation is factorizable. discriminant is positive, 15 2 b the × 15) = so 4 there will be two unique solutions. 2 x 8x x = 3; + 15 x 1 = = (x 3)(x 5) 5 Both values 3 and 5 satisfy Whn x = 3: width = 3, lngth = 8 3 = 5 Whn x = 5: width = 5, lngth = 8 5 = 3 Th dimnsions Practice of th rtangl ar 3 m by 5 ths Slt x < 8. 7 problms, th most rat int a mathmatial mthod to solv modl th to solv quadrati th problm. A quation. skth solving gardnr has 40 m of gomtri modls, you Problem 1 < m. With In 0 2 draw to a hlp visualiz th problm. fning to mak thr qual rtangular plots. 2 Th total ara dimnsions 2 50 m an xisting of of of th th fning thr plots rtangls, is usd to is and mak 30 m nd thr . Dtrmin th th dimnsions sids of a onstraints of ah rtangular on th rtangl. ara, using 2 Dtrmin 3 A wall th rtangular as th fourth dimnsions gardn sid. of th masurs Th ara of rtangular 24 m by 32 th rtangl is 150 m . ara. m. A path of uniform width x is 10 built all around th outsid of th gardn. Th total ara of th path and 2 gardn is 1540 m . Find th width of th path. 6 4 A rtangular sids of th swimming pool has pool width x masurs mtrs. 10 Th 4 ara is of th pool ara on its 3 4 34 11 Equivalence own. m total Find x by 6 ara m. A pavd inluding ara th on pavd two x m m A LG E B R A 5 Th of 6 primtr th A studnt th sam from of a rtangl is 42 m. Its diagonal is 15 m. Find th width rtangl. yls hom north from distan and to hom plus shool an is to shool, additional 17 km, nd 7 du km th north du for ast. distans a If that distan th th x dirt km, thn distan studnt yls ast. 3 7 A box Find 8 A has a squar bas of sid x m, hight 4 m, and volum 289 m . x box with utting an opn squars of top qual is mad siz from from a ah rtangular ornr. Th pi of ardboard ardboard by masurs 2 50 9 m by 40 m. a Dtrmin b Find Two th Th th sid volum numbrs ara hav th lngth of a of th of bas th is 875 squars m ut from ah ornr. box. dirn of 3 and a produt of 88. Find th numbrs. 10 11 12 Th produt Th sum Find th Whn of th onsutiv numbrs is 9 odd and numbrs th sum of is 143. thir Find th squars is numbrs. 153. numbrs. squar numbr. Example Whn two two two th original of of a numbr Find th is drasd by 1, th rsult is 4 tims th numbr. 8 braks ar applid in a rtain mak of ar, th lngth L of th skid 2 in mtrs in km/h aidnt tim of is at givn th by tim lavs L = 0.168s whn skid th marks 0.8s braks + 0.3, wr masuring 50 whr rst m. s is applid. Dtrmin th A spd ar th of th involvd ar’s spd ar in an at th braking. 2 0.8s 0.168s + 0.3 = 50 Write the equation. 2 0.168s 0.8s 49.7 = 0 a, Using th quadrati b and c quadratic a = 0.168, b = −0.8, c = = −15.0; 1 s = be so the factorized. the positive value makes sense 19.7 2 in Th ar Th of decimals, cannot −49.7 Only s are formula: was travlling distan th ar distans a and to ar at skids wathr alulat approximatly dpnds on onditions. travlling 20 svral Car spds, fators, aidnt to the context of the question. km/h. hlp inluding invstigators disovr th th us spd skid aus of an aidnt. 11.2 More than one way to solve a problem 4 3 5 Practice 8 Problem 1 Th solving amount of mony in bank aount A is givn by th formula t A = P(1 + r) whr ompoundd invst you $5000 with P is annually and your th and would rst initial yar t lik of is it invstmnt, th to tim b in is yars. worth univrsity r intrst Your $6500 osts. th aftr two Dtrmin rat mothr th wants yars, to intrst to hlp rat shnds. 2 An intr nt months tr ms ompany bfor of th going was listd bankr upt. numbr of on a Th months x small pri that th stok P of xhang th stok for ompany’s tradd on svral stok th in xhang 2 isgivn by months it whn 3 A = sold tikts Price −2.25x for th organizs From 9500 sold Copy = + 40.5x ompany + to 42.75. go Dtr min bankr upt, in th othr numbr of words 0. stadium. thy a took P (x) harity th P(x) a past tikts. inrass and sor omplt Decrease vry rais thy $1 mony. know dras that in ticket Increase price 15 15 15 = 0 14 15 14 = 1 ar whn tikt th pri, 15 000 tikts th sats ost in $15, numbr of tabl. in Total ($) Thr 1000. th in to xprin For by gam attendance Total sales 0 1000 × 1 9500 = 1000 9500 + 1000 15 = 10 500 14 × × 9500 10 = 500 142 = 12 b From of c 15 th tikt Writ an nobody d p last row pri quation would Dtrmin th would sll you e Dtrmin f Considr unsold 4 3 6 in th your sats if th tabl, nd a funtion for sals gnratd in trms p to buy a tikt at nd pri that tikt tikt Solv that it pri that using would th would most maximiz b so xpnsiv int sals. How that mthod. many tikts pri? pri answrs you th tikt. sold for ndd d and tikts 11 Equivalence at to e. ll all Did th pri 15 000 what that sats. you givs ould do with maximum th sals. 500 147 13 p ($) attendance 000 A LG E B R A 4 A swimming tam intrnational shown in this Price in a Find and of slls t-shirts omptition. A with thir survy into to rais and mony for prditd an sals is tabl. t-shir t Euros Predicted (p) number t-shir ts sold 5 165 10 150 15 130 20 118 25 97 30 85 35 65 40 56 45 42 50 28 th logo pris lin numbr of of bst t t-shirts that bst sold. of (s) dsribs This is th th rlationship dmand btwn pri Lins funtion. of ovrd 5 b Dtrmin th rvnu c Dtrmin th t-shirt pri that would maximiz rvnus. d Dtrmin th t-shirt pri that would guarant that A 36 ski rntal rntals rntal pr pri, day, th and hargs day. A ski avrag vi a rntal journal ski f of artil rntal $50 pr stats businss pair that an of for no skis t-shirts and vry xpt to $5 los two b Dtrmin th ski rntal pri that would maximiz rvnus. c Dtrmin th ski rntal pri that would guarant th to hav xris to follow numbr a Your bik a of will linar biks a nw ost how ii $120 and many to mak. is th c Writ a funtion for th total d Writ a funtion for th prot e Calulat what th maximum th biks, to pri and by s = of ould bik osts Sals pri you Us on shop ould not of will suh 80 in th want $800 to 000. whr sll Eah (dmand) 180p, bik at you b biks 000 th sll whih s tnd is th dollars. pri of $500. b prot xris start-up modld p iii funtion of and biks $300 linar kind funtion sold i th in rntals funtion. advrtising Dtrmin $100 sold. skis. dsignd rtailrs. 4.3. vrsa. rvnu You ar avrags th any ar inras Dtrmin out t topi funtion. a rnt 6 shop pr bst in writ of us th osts you th this of funtion produing would bik to rvnu mak would b alulat if th th on for th sal biks. biks. produing you of wr pri that to th biks. mak would no nsur a prot. 11.2 More than one way to solve a problem 4 37 Objective: ii. slt D. Applying appropriat mathmatis mathmatial in ral-lif stratgis ontxts whn solving authnti ral-lifsituations Draw and method label to suitable solve diagrams, create equations and select the most ecient them. Activity Do 1 th opn Suitass ar Eah sht sht is problm mad is opnd Draw a b Exprss all c Exprss th d Dn e Us up th your and Dtrmin in Prati 7 qustion rtangular half, squars shts ar 8, of ut bfor lathr from th this 60 ativity. m by ornrs 92 and m. th again. diagram th in from foldd a as 2 box and labl th dimnsions volum of th variabl in trms as for of using th sid your ths of ah squar utout. variabl. dimnsions. onstraints. GDC or th siz th siz 350 m softwar of th of to dtrmin ut-out th squars squars to th that ut out maximum giv to this giv volum maximum a as of th volum. with 3 volum 3 Crat of th Us 18 a mathmatial squars suitabl maximum 4 Rsarh to b suitabl th maximum modl ut softwar volum alulat giv to to for siz siz out of xplor svral ass th volum whih from th siz siz dirnt for a your st of st and of you to did on th sizs rtangl. th starting travl rtangl for nabls any of th 3 squar giving th rtangls. ass. siz of Us your squars to modl ut out to ass. Summary 2 Th two null or factor mor law stats numbrs is that zro, if th thn produt at last of on Th fators must b formula to solv ax + bx + c = 0, of a th quadrati ≠ 0, is . zro. 2 Th For two fators a and b, if ab = 0 thn a = 0 par t alld b = 0, or if f (x) f (x) = th quadrati formula, b 4ac, th discriminant, and th symbol 0 = us × g (x) h(x), = 0 whr or h(x) g = and 0, or h ar is th Grk lttr dlta Δ. W writ Δ = b 4ac funtions, ● If Δ < 0, th quadrati has no ● If Δ = 0, th quadrati has on ral root has two ral roots. ral roots. both. 2 Whn a quadrati is of th form ax c = 0, c > 0, (a you an us th addition prinipl to ● ax c, and th multipliation rpatd prinipl to If Δ Th solution is > 0, th th disriminant is a prft squar (.g. . 1, 4, 9, 16, ...), fatorizabl. 4 3 8 quadrati gt Whn . root). rarrang 2 to for 2 g (x) thn is w both. it Whn of or 11 Equivalence thn th quadrati xprssion is A LG E B R A Mixed 1 Solve your practice ah quadrati answrs by fatorizing, graphially. Lav and your hk 8 answrs A is xat. rtangular lawn surroundd Th by ombind a masurs bordr ara of of th 8 m by 4 uniform lawn and m and width. bordr 2 2 a is 2 x − 2x − 24 = 0 b x − 6x = 2 c = 5x + 4 d 17 x 2 2 Solve, hk + 7x if = 2 by answrs omplting graphially. = th 8x − 59 = 0 b x = bordr. 21 8 squar, and 4 m m your + 12 x 2 = −23 2 − 10 x e 2x + 26 = 8 3x d + 6x = 7 9 2 Th hight Solve, giving 8x − 3 f a right-angld triangl is 5 m lss 2 2x − 5x − 3 = than 0 if possibl, answrs using to 2 th d.p., quadrati and hk its answrs 10 2 + 13 = 0 b x − 5x = 1 + 3x x d = − 11 x 2 of th triangl is 42 m . hight. On sid of a Find th Find two triangl and sid 7 m lngths is 2 m longr of th shortr than than th th third sid. triangl. produt onsutiv is odd intgrs whos 99. 2 + 8x = 1 f −3 x + 2x = 12 12 Solve, and ara = 2 3 4 x Th 7 1 2 2 3x itsbas hypotnus 2 + 10 x bas. formula, your graphially. x of 2 = Find 4 th xat. + 6x x e of 2 x c c width − 6 Lav 2 a th 27 − 2x 2x f possibl, your answrs 3 Find 2 −5 x a . m 2 6x e 165 if mthod. possibl, Lav using your th most answr appropriat xat and Chk your answrs squar itslf by Find two of 72. a numbr Find th xds th numbr numbr. ompltly 13 simplid. Th onsutiv positiv intgrs suh that graphially. th squar of th sond. th rst lss 17 quals 4 tims 2 x 2 a (x 5 2 + 3) + x − 9x = + b 8 2 = −x 2 2 c (x 2 − 2) − 11 = 0 d 2x (x − 1) − 5 = 14 Th hight into th h in mtrs of a football kikd − x air an b modld by th funtion 2 2 e (2 x − 6) h (t ) = 12 a f (2 x + 5)( x − 1) = (x − 3)( x = −4.9t Find ths nxt problms using th most Round your answrs to 5 Th solving lngth of a rtangl whr aftr bing t is in sonds. kikd it taks th c is 3 hit th ground. Determine how long it taks th objt to appropriatly. rah Problem long + int b mthod. how t + 8) ball Solve + 24. m gratr than its 15 For Th a hight how long prots of of 20 was an mtrs. it abov this intrnational hight? tikt 2 width. Its ara is 108 m . Find th agny dimnsions an b modld by th funtion 2 of th P (t ) rtangl. = −37t numbr 6 Th lngth of a rtangl is 2 m mor of + 1258t tikts − 7700, sold and whr P is in t is th dollars. than Determine th tikt pri that would lav th 2 3 tims its width. Its ara is 85 m . Find th agny dimnsions of th Th lngth of a rtangl is 1 m mor than If th lngth of th rtangl is ara of th loss. A squar rtangl inrass by a pi box. of Aftr ardboard 5 m is squars to b ar formd ut from ah doubld, 2 th or its into width. prot rtangl. 16 7 no 30 m ornr and th hav volum sids ar foldd up, th box will . 3 Find th dimnsions of th original a of 400 m . Find th lngth rtangl. sid of th original pi of ardboard. 11.2 More than one way to solve a problem 4 3 9 of a Objective: ii. slt ral-lif In the and D. Applying appropriat mathmatis mathmatial in ral-lif stratgis ontxts whn solving authnti situations Review select the Review in context most in section, eective draw method to and label solve suitable diagrams, create equations, them. context Scientic and technical innovation Quadrati projtil ground that is quations through at dirnt proplld kiking a sor launhing an spa, modl and tims. with ball, A for th its path hight projtil through doing th is th high of a abov any air, jump a Writ th quadrati b Determine: suh or as i th ii how modls of projtil motion tak maximum iii how thr initial th hight initial th o vloity alration th A long with whih th objt = objt taks to rah this hight th objt taks to strik th again. du to is launhd gravity that upward at 39.2 from m/s. ground lvl Determine how movs ats th projtil’s altitud is 34.3 m or abov. all for alulating th hight abov Suppos NASA sixth of 2 (−9.8)t +V t of th gravitational is: 1 h (t ) rahs wants to launh a prob on th objts. formula ground th long projtil surfa Th objt ground 4 falling th fators: long ● hight into dirtly ● objt. vn 3 th this objt ground ● for rworks. Quadrati aount modl th th th moon, pull of whih th alration launhr is 0.5 has Earth du to on (and sixth th thrfor gravity). Th on hight m. + h i i 2 a whr th alration du to gravity (on Earth) On th moon, how long would it tak th is prob to rah a hight of 60 m if its initial 2 9.8 m/s , V is th initial vloity, and h i initial is th i vloity is b If th initial longr Problem will A m/s? modl th rokt ground is with launhd initial from vloity 1 quadrati vloity it b in is th 24.5 air m/s, on th how muh moon solving ompard 1 15 hight. modl h (t ) m abov (It Use bothplas.) m/s. th is a launhd similar from launh th on surfa Earth? in 2 ( −9.8)t = 2.5 49 to + 49t + 2.5 to c Explain how you think sintists tst thir 2 determine how long it taks for it to hypothss land. th 2 An objt is launhd dirtly upward moon m/s from a platform Reect and How you hav 30 m (or is so dirnt high. th statmnt of inquiry? Giv spi xampls. Statement of Inquiry: Rprsnting modls and 4 4 0 Mars) discuss xplord pattrns with quivalnt mthods. 11 Equivalence th bhavior whn th of objts for at thr 24 about forms an lad to bttr systms, than on Earth. of on gravity Seems rational to me 11.3 Global context: Objectives ● Solving linear Scientic Inquiry and quadratic rational equations and technical innovation questions ● What ● How ● How is a rational algebraic equation? F algebraically ● Using and graphically equivalence to do equations Using and rational solve solve equations with fractions? are the dierent methods of solving C rational ● you solve equations to model algebraic equations related? situations ● What ● Is makes dierent methods equivalent? problems there a ‘best method’ for solving D rational ● Does equations? science solve problems or create them? ATL Transfer Apply skills and knowledge in unfamiliar situations 10.2 Statement of Inquiry: Representing helped change humans apply and equivalence their in a understanding variety of of forms scientic has principles. 11.3 E10.2 4 41 MROF rational transformations Y ou ● should apply already know equivalence transformations linear 1 to how Solve solve a 2x to: using + 3 = equivalence 5x 9 b transformations: 4(x 1) = 2x + 7 3x equations c = 10 2 ● carr y out the operations four on arithmetic 2 Simplify : x rational 5 b 3 algebraic 7 3x + a x + 2 4 x expressions 2 2 2 x 6 c x 2 16 x + 4 x + 3 x d × 14 x ÷ 2 2 x ● factorize quadratic 3 9 4 x 5x + 5 12 2 a 2 x 16 b 3x 2 c solve quadratic equations 4 5x 6 d 3x b x c What ● How is a do 2x algebraic rational you 18 = 0 + 2x = 3 2 + 7x + 3 = 0 d 3x 4x 1 = 0 equations algebraic solve 12 2 2x 2 ● 5x Solve: 2 Rational 6x 2 x a F 49 Factorize: expressions ● x equation? equations with fractions? p A rational number is of the form where p and q are integers, and q ≠ 0. q P (x ) Similarly , a rational algebraic expression is of the form where Q (x ) Q(x) ≠ 0. A algebraic The rules algebraic rational algebraic equation is an equation containing rational expressions. and procedures expressions Example and you use with rational numbers also apply to rational equations. 1 There is no standard The total electrical current (16 amps) used by two appliances is given by voltage x = 16 , where x volts is the voltage used by each 10 countries. voltage used by each most appliance. countries 200 it is and x + = 16 240 10 volts x 30 and in × + 30 × = 30 the × 16 Americas 127 x = 480 4x = 480 x = 120 Use the each Each 120 of it is 30 between + most x 10 3x while 30 Japan appliance uses 120 multiplication term by 30 to 100 and volts. principle. Multiply simplify. volts. 120 + 10 In 30 between x by appliance. all the used x + equation Find mains the = 12 + 4 = 16 ✓ 30 4 4 2 11 Equivalence Check by substitution. A LG E B R A Multiplying eliminates each one Practice Solve these x rational 5x + 3 − 3 3x 2x 4 x + 7 = by is the no lowest longer 2x your a answers − 4 common rational −1 x 1 − 3 7 + 4 − denominator equation. or 3x − 5 + f. 2x 4 x 4 −1 − x + 2 = 3 2 = 5 5x 8 s. x 2 8 3 2 + 1 6 6 to = 3 4 x 5x = 3 1 − 5x 6 exact, 2x =1 + 4 Problem x +1 − 8 6 12 solving 1 − = x 4 3 Reect ● leaving 4 −1 + 3x it 7 5 2 2 so + 5x = 5 2 − 9 2 2x + 9 equation 6 6 7 the equations, 5 4 x in denominators 1 = 2 4 x the 3x + 1 fraction of How and is discuss question 9 in 1 Practice 1 similar to and dierent from the other questions? ● How did that When C ● How aect are What process dierent the equations ● the dierent you is used the methods to solve the equation? same of solving rational algebraic related? makes dierent methods equivalent? Tip Multiplying solving by simple denominators or equations the lowest rational are have common algebraic rational denominator equations. numbers. variables in the What The is a useful LCM happens is method easy when to for nd rational when the expressions denominator? Finding lowest denominator same as lowest Exploration 1 at these pairs of rational expressions and their lowest two is the nding the common multiple, of Look the common or LCM, more common numbers or two denominators. or Rational 2 expressions Lowest common more algebraic expressions. denominator 3 x(x , x x x +1 + 2) + 2 1 7 (x , x 5 + 1)(x 3) − 3 1 x(x , 7) 2 x x 7x Continued on next page 11.3 Seems rational to me 4 4 3 10 6 , (x + 2)(x 2) (x + 1)(x 5)(x 1) (x + 2)(x 1)(x 1) 2 x 4 x 2 8 3 , (x + 1)( x 2x − 5) 5 (x − 1)( x + 1) 3x , 2 + x x − 2 x + 2 −1 3x 1 x(2x , 2 + 1)(x 1) 2 2x + x x 2x 1 − x −1 4 2 (x , 2 x + 2 x 3)(x + 3) 2 − 9 1 x + 6x + 9 Determine the rst step in nding the LCM of two algebraic rational expressions. 2 After that rational rst step, algebraic explain how you would nd 7 3 Find the LCM of the LCM these three x 3 , expressions: 1 The +1 2 x 6x x − 7x + 6 2 denominators lowest two and 2 x Practice of expressions. common of two or more denominator of algebraic the given fractions are given. 2 a x, x d x, x 2 g x, x 2, j x b 2x, e x, 3x 2, + + 1 2 h x, k x x x, x , 3x f x 2, x i x 1, x 1 l x 1, x 1, n x, + 2 2 x + 1 + 4, 1, 2x + 2, x 2 2 x, x 2 m x a, x 2 p 3x Do + 1, x 8, x 2x and you see + use Find solve the + x 1 x x 6 o 2x, 2x 3, x + 1 any 4 4 4 2 potential issues with having variables in the Explain. value(s) rational same 2 discuss any Exploration To 8 2 1 denominator? ● + 2 , Reect ● the 4 c 2 x Find denominators. of x that are not allowed in each expression in 1. algebraic procedure as equations for with rational 11 Equivalence variables equations in with the denominator numerical you denominators. A LG E B R A Example 2 3 Solve the equation 8 and = x LCM(x, x 2) = x x(x − 2) × x (x − 2) = x 2 ) ( x 2 ) = 8x 6 = 8x 2) algebraic each x This only 3 x 2 x 2 = 1 for x ≠ 2 solution is excluded valid Check − −1.2 − RHS Why are these check your you ✓ discuss allowed numerator are to and you 3 put lines through the factors that are common denominator? really multiplying by when you do this? 3 rational your equations answers using appropriate algebraically. Make equivalence sure you check transformations, for extraneous solutions. 4 9 1 10 = x 4 4 2 5 + 3x 3 4(x 10 5 4 − 2) 5 = x 5 + 3x = 2 − x x 8 x + 1 = − 2 10 = 7 + x − 2 x − 2 3 9 x x 5 6 x 3 = 4 72 2 2 − + 1) + x (x + − 2 + 4 3 x 6 = x = 4 3 7 x 15 2 x 2. answer. 2 −2.5 number Practice and = and both What Solve and = −2.5 2 Reect ● the 0 8 = to are = −2.5 8 ● since values 1.2 RHS: = fraction. 3 = x LHS equal a = −1.2 5 x in 6 = − LHS: place = 1 for x ≠ 1 , 8x 6 x to expression x × 2) 3x 5x ( − 2) = Rearrange × (x x 3(x algebraically. 8 = x 3( x answer Find the lowest common denominator. x × your 2) 3 x (x check 2 x + = 4 x +1 11.3 Seems rational to me 4 4 5 In rational the equations, denominator you equal to must exclude any 3 For example, in the rational to x zero. = eliminate An 0 If and the x that the allowed you the the Reect because to the solution original in have 2 the is one equation. equation solutions, and you ● How ● What could ● What is ● What values easy is the First reject variable that make need to exclude the 2 one of includes any the denominators either 0 or 2, you equal need to algebraically, determine make that are any the not values but of x denominator does that not are zero. not When allowed. 3 = 2 − 4 to you nd 4 + it you they 2 2 x x + 2x x determine do rst, to the LCM make it of the easier algebraic to fractions? determine the LCM? LCM? of x are not allowed? 3 1 x 4 + Solve x make that because discuss equation: Example they equation 7 For the answer. extraneous satisfy = solution of 8 = equation x values values 0. = and check your answers algebraically. 2 x − 6 x − 2 − 8x x + 12 2 x 8x + 1 12 − (x 2) 6 x − − 6)( x Factorize the denominator on the right side. 4 = ; 2 (x − 6 )( x − 1 (x 6)(x x + x = x − 2) ≠ 6, x ≠ 2 Identify = (x + − 6)( x 2) x 6 + any values of x that are not allowed. 2 x(x 4 6) = 4 5x 2 = 4 5x 6 = 0 1) = 0 Use the multiplication principle − 2) x (x x 2) (x − 6 )( x − 2) with the LCM of all denominators. 2 x 2 x (x Since x ≠ 6, 6)(x the 1 only 6 1 = − −1 − 2 ⇒ possible 1 + LHS: −1 − + Set 1 + 7 x = 6, x solution = is −1 x = −1. Reject LHS = RHS 4 4 6 any and to 0. solve. invalid solutions. original equation. 4 21 = 2 − 8( −1) + 12 equal Factorize Substitute ( −1) quadratic = 3 = RHS: the 1 + 8 + 12 21 ✓ 11 Equivalence the solution found into the A LG E B R A Practice Solve these 4 equations using appropriate equivalence transformations. Make 7 5 10 x + 1 2 x = 2 2 x + 2 x − 2 1 x 2 + check = sure for you extraneous 2 4 x − 2 x − 4 x − 6x + 8 solutions. 2x 4 2 2 = 3 1 = 4 2 x 2 − 10 x + 16 2x x + 2 x − x x −1 3x = 5 + 2 2 x Are − 3 x there − 9 any other methods Exploration For the 2 If b for = d, a, b, and c, to equations? to be be equal, determine what conditions d what must be true about a and c in order Select any pair of equivalent fractions, for example true about across these the equal products. sign, so Explain 3 if × 24 you and 6 think × 12. that , and Generalize your result for any pair of equivalent it Suggest is Prove 6 State be 7 your in result which using equivalence examples from what always is true. c fractions = . d b 5 multiply 24 a 4 the 12 = 6 diagonally for equal. 3 3 must d and determine fractions rational c fractions b hold solving 2 a 1 for transformations. Practice 3 and Practice 4 this result would useful. State the condition necessary to use this result in solving rational equations. 1 Consider again the rational equation in Example x 4 + 3: = 2 x Instead terms so of in you multiplying the get equation an both with equivalent sides the by the LCM as LCM, − 6 x − 2 happens denominator? The if x − 8x you LCM is + 12 write (x all 2)(x the 6), equation: 1( x 2) x (x 6) 4 + (x what − 6 )( x − 2) = (x − 2 )( x − 6) (x − 6 )( x − 2) Tip which simplies to: 1( x − 2) + x (x − 6) Tr y 4 using this = (x − 6 )( x − 2) (x − 6 )( x method − 2) Practice in 5, before 2 x − 5x − 2 4 = (x − 6 )( x − 2) you (x − 6 )( x decide method Since the denominators are equal, the which − 2) numerators must be as well, so: for you solving rational prefer a equation. 2 x 5x 2 = 4 11.3 Seems rational to me 4 4 7 Set the quadratic equal to 0 and solve: 2 x 5x (x 6)(x x From the original denominators So x = 6 is an Practice Solve sides the these of 5 ≠ 2 and solution. equations equation equals equation 4 − x x to by 1) = 0 = −1 or ≠ The rst sign. x 6, since only these solution exclude any 10 x (x sure values is 4 equal that extraneous x = would make −1. you denominators check − 2) your 10 3 x both in 4 − 2 − 2x x 2 5 = 3 x on answers answers. = 2 x obtaining Make = − 2 x 0 zero. extraneous rational the to 6 = 5 original 1 equation equal = + 6 x − 2 2 2x 5 6 4 x + 4 6 7 = x 2x + 5 = 2 x x 4 + 2 Reect What x and makes x 2 discuss dierent rational ● Is ● Does there Choose two multiplying 2 State any 3 Which 4 Solve 2 5 the do not Justify 4 4 8 a you results your solving Practice think using the or rational create 5 and using equations? them? solve is equations better? the them 1 b 3 − x − 1 about be the your same answer. 11 Equivalence 2 the your again, this time two choice. 1 1 1 = c x 2 answers, methods. prefer: = x notice would you x + from Explain method 2 − 1 what the from you 2 State for problems between = a problems LCD. equations 1 + 1 method’ solve questions by + a x 8 3 method 1 a x 2 equivalent? real-life ‘best dierences these − equations science Exploration 1 a x 5 methods Modelling D − 1 2 = 6 2 2 x and independent + 1 explain of the x − 4 x − 5 whether method or you use. x A LG E B R A Objective: i. solve In this A. Knowing problems practice equations in Practice set that you rational each 1 motorist miles On for in brand B, same given she b Brand a various A below Select the appropriate problems into appropriate rational into a most rational ecient equivalence equation. method Make for sure solving transformations. the Interpret context. 1080-mile For the travels the 3 journey return miles costs the number 35 cents of trip, fewer modelled of a miles per dierence concentration be contexts on brand she per uses A the gallon, of gasoline less and and expensive uses 4 averages brand gallons B. more journey. Determine can the of solutions. described use gallon. a The variety correct variables. and the Calculate 2 all makes per the a translate the situation equation answer x will nd in solving identify your A to understanding 6 Problem Translate correctly you order and per gallon, in the and cost medication gallon in for a for brand the the B initial costs 1080-mile patient’s 32 journey. cents per gallon. journey. bloodstream C (in mg/l ), by: Doctors and nurses 6t C (t) , = where t is the time (in hours) after taking the need medication. to know the 2 t a 4 Determine how concentration many will be hours 2 after taking the medication concentration of medication a the in mg/l patient’s bloodstream, b How many solutions solutions you found did you made nd? Explain whether or not all so the a sense. they safe can time between c One dose equals 5 mg/l and the concentration should never be more decide interval doses. than 1 6 mg/l. Determine a safe time interval between doses. 8 3 On a and mountain then faster rate 4 To than at stay group high The of hikers They entire walked for generally excursion 7 miles walked lasted 4 3 on a level miles hours. per path, hour Determine the uphill. divers need pressure percentage percentage of uphill. hiked underwater, under a miles hiked. they recommended The 12 they which oxygen trail, hiked oxygen can of air act that like oxygen (P) in contains poison the air recommended enough in the changes at depth oxygen. body, as d so you meters However, the dive is deeper. calculated 1980 using the formula P = d a At sea level Explain b 5 Find Juan same the drives time the how 20 that percentage this depth + 99 at of compares which km/h per Maria the hour drives oxygen to the in value the recommended faster 75 km. than Find air is approximately calculated using amount Maria. their Juan driving of the oxygen drives 20%. formula. 100 is 10%. km in the speeds. 11.3 Seems rational to me 4 4 9 on 6 Carl’s water Sareeta’s long 7 A it would scientist water. 20m pump pump take to studying When the upstream current) removes removes in 70 10 the remove sh river seconds. 10 wants speed (against the 000 same of 000 to is l water amount l of nd 0.5 current) Determine and how 45 fast fast records m minutes. minutes. using how she 15 20 water out m/s in in both a salmon that a salmon neighbor how pumps. swims salmon downstream the His Determine (with swims in still swims the in still water. Summary p A rational number is of the form where p and Or: Rewrite the equation so that all terms have q q are integers, and q ≠ 0. Similarly , a the common denominator. are then An extraneous The two numerators rational equal. P (x ) algebraic expression is of the form , where Q (x ) Q(x) an ≠ 0. A rational equation algebraic containing equation rational that is the algebraic you original values expressions. of because To solve a rational equation, rst nd common denominator (LCM) x solution equation. that they to algebraically, are First not make the an equation but does determine allowed in is not any the denominator one satisfy equation zero. When the you lowest nd of all have the solutions, reject any that are not the allowed. denominators. Either: LCM Multiply to Mixed Solve both eliminate all sides the of the equation by the fractions. practice these equations equivalence using Problem appropriate transformations and the 6 ecient method. Make sure you check a Determine 2x 3 solutions. Leave 3x x answers 4 x = 1 all 3 x − a pair of consecutive integers 5 whose reciprocals add up to 6 exact. x b Determine if a pair of consecutive integers = 2 + 3 if for exists extraneous solving most 4 x − 4 x 3 − 3 exists whose reciprocals add up to 4 2 3 4 + 10 3 + 4 x (x − 4 = 2) x x − 2 2x + 20 5 = c 2 x + 2x x x + Determine if a pair of consecutive even 2 3 integers 2( x + 7) 5 exists whose reciprocals add up to 4 − 2 = x 4 2x d + 8 Determine if a pair of consecutive odd 11 integers exists whose reciprocals add up to 60 ATL Review in Scientic context and technical innovation 1 The 2 water km/h. for 15 On km, returns takes in to 3.5 the a kayaking takes his Danube a trip half-hour original hours Delta Max his at about paddles lunch starting (including ows break, point. lunch His Let upstream and then entire x Then (x km/h the 2) represent kayak’s km/h and the average trip total speed distance = total 11 Equivalence speed downstream break). Average 4 5 0 kayak’s time average upstream is (x + 2) speed. is km/h. A LG E B R A a Justify the the kayak expressions going for upstream the average and speed of ‘speed downstream. 12 means b Write an expression for the time taken for i the river’ upstream x, where x is the speed of the is current. 4 Lenses are images on used to a to look at objects, and to project screen. downstream. Use your expressions from part b to write an The equation representing the whole focal parallel Find the average speed of the length of a lens is the distance journey. between d to travelling travel: upstream ii c to relative speed the 12 kayak km/h the kayak in the lens rays of and light the point passing where through the still lens would converge. water. 2 When resistors are connected in parallel, the The total resistance is R given distance between a lens and to the focal the image by: tot produced d is related length f and i 1 1 1 1 the distance between the lens and the object d o R R 1 R 2 R 1 tot 3 by the 1 + formula = d d o Find the resistances of two resistors connected The focal One resistance is three times as large as Total resistance is 12 resistance is 3 ohms Find greater than An object Total resistance is 2 Find in a lens the resistances parallel where of the three resistors resistance of the connected one is is than the smallest one, and the other 15 cm. twice as large away as The the image original how far the object is from the lens. is 2 placed cm in more front than of the a lens, focal at a length. The asthe smallest appears focal to length be of 4 cm the from the lens. Find lens. The human eye contains a lens that focuses has an resistance far 2ohms c greater as ohms. image c of twice the distance other. be ohms. b One to the object. other. b length where: appears a f i in a parallel 1 image on the retina for it to be seen clearly. one. An object is at a distance from the eye that 10 The total resistance is ohms. is 7 d An engineer resistance this with one is 8 of wants 3 two to ohms. build Show resistors, ohms greater a circuit how where than he the the with can (on do Lucy makes upstream and motorboat 12 km/h speed of an 8-hour 45 relative the to back at an the trip of 45 downstream average river. the Find of from other the than the side focal the eye of to the length of focal the retina lens this length. from is The 20 the and How you eye. An airplane km in on headwind. speed a in of Determine the same still air. travels time The 910 that it speed Determine miles with travels of the the 660 a airplane wind’s tailwind miles is with 305 speed. the discuss explored the statement of inquiry? Give specic examples. Statement of Inquiry: Representing humans change apply their and equivalence understanding mm object). current. Reect have km travelling round longer other. 5 3 cm distance total resistance 20 of in a variety scientic of forms has helped principles. 11.3 Seems rational to me 4 51 m/h 12 Generalization A general statement made on the basis of specic examples In mathematics we talk about two different types of ‘All generalization. The rst involves looking at generalizations dangerous, information and trying specic that might specic problems to underlie by Hypernyms hypernym includes a it The to a specic that rather cauliower ask if they 4 5 2 use ask and with are would like other more something is to general language broad words. potato if with meaning So, and Alexandre ones. - to them their vegetables. like meal, is since all. It would generalize they’d that vegetable appropriate individual broccoli, we be ideas: carrots, might even this less tackle cabbage, hyponyms. hypernyms beans The includes called someone about at a carrot, which out Hyponyms specic onion, words we than word term in and more for general say a other, hypernym is is it. looking Generalization A nd are specic generalize and Dumas one.’ Horse Your friend school, and wearing Look from think on sense at a most your she each straw the of says passes day, hat any to other friend’s feeding general specic The horse ● The farmer feeds ● The farmer is ● Your ● The farmer ● The horse ● Your Is To the If if a The not a digit is method is evenly may remove the likely on she and to the sees brown that wears to but only to a to farmer horse. rank be way them true. could be Can in order you made based on who days feeds the horse same time horse at the divisible divisible subtract units school hat school to carrots school a divisible need least person evenly and a statements horse racing travels number result 3843 is to statements walks always carrot anything only evenly removed the the the to day observations? eats never friend 3843 see never friend true every exception, a general be ● eld without following likely a be the by by 3, 7, 7, then remove the amount the several leaving day 7? doubled repeated digit, by every units from original digit the number of the number, remaining is also double number. divisible by 7. times. 384: 384 − 6 subtract 378 remove the the doubled units number digit, 8, 3 leaving 37: 37 − 16 subtract 21 this is a evenly This the ● is a Is this Try doubled multiple divisible specic method the of by example number 7, so 8 3843 is 7. that works with described. enough some to other say that numbers the for general method always works? yourself. 4 53 Seeing the forest and 12.1 the trees Objectives ● Identifying Inquiry patterns in number problems questions ● What is a conjecture? ● What is a generalization? ● How F ● Solving a ● more complicated general Making problems by looking at case generalizations from a given pattern C MROF ● D ATL Critical Draw Dierent What generalizations be used to solve problems? are the risks of making generalizations? thinking reasonable Conceptual can specic conclusions and generalizations 8.1 understanding: forms can be used to generalize and justify patterns. 12.1 12.2 E8.1 4 5 4 A LG E B R A Y ou ● should expand already brackets algebraic and know simplify how 1 to: Expand the brackets in each expression. expressions a 2 2x(3 4x) Simplify 3 6 x b these (4 + x)(1 3x) expressions. 2 3 y 12 x a 5 y 12 x b 2 2 x ● understand (lowest and the terms common GCD LCM 3 Find multiple) (greatest a or HCF In of in ● What is a conjecture? ● What is a generalization? mathematics, from the one specic information underlying LCM of : 8 b 6 and 9 Find the 12 GCD and (HCF) 54 b of : 10 and 75 factor) Generalization F the and 3x (highest a common 6 common 4 divisor) 3 4 y to the and trend, of the general. trying rule meanings or to mathematics of Often, make a generalization it means statement relates looking (a at a to reasoning limited conjecture) about amount an pattern. Typically , Reect and discuss a Look at the following powers 1 4 of 4. 4 4 generalization involves some 7 = = 2 information trying 16 4 3 = 65 536 you 9 = 64 4 = 256 4 = = = There they a are are Suitable 1024 = 4 4096 general several all even. 4 statement things You pattern, at more information. = 4 194 304 = 16 777 216 power ● Every odd ● Every even important is 4 power you of to bear will 4 of in in a 4 or a with that hold the notice notice with ends mind powers of about 4. the something powers about of the 4. For nal example, digits. include: with always discussed also ends 4 the might might ends power generalizations true of about might generalizations Every always a looking 12 ● It’s nd 1 048 576 11 6 Make you 10 5 4 patterns If 262 144 try 4 any notice. don’t 4 4 to 8 = describe 4 collecting 16 384 and 4 forming 1 a 4. a 6. you true. chapter 6. don’t yet Proving on know that a whether particular these conjecture is justication. 12.1 Seeing the forest and the trees 4 5 5 A conjecture Usually has it been is is a mathematical consistent proven to be with true, statement some we known usually which has not information. refer to it as a yet Once been a proved. In 1994 Wiles conjecture rst theorem conjecture is similar to the idea of a hypothesis in to Fermat’s science. conjecture, stated that positive Practice b Write down the rst few powers of and the 5. a general statement about the last digits of the powers of a 5. c For any values Write number, of its down Suggest a the digits. some general digit For sum of example, multiples statement of the number the the about digit number the is sum digit 9. found of List sums by 842 is their of adding 8 + 4 digit + together 2 = b of Look at the multiplication square 2 3 4 5 6 7 8 9 10 1 1 2 3 4 5 6 7 8 9 10 2 2 4 6 8 10 12 14 16 18 20 3 3 6 9 12 15 18 21 24 27 30 4 4 8 12 16 20 24 28 32 36 40 5 5 10 15 20 25 30 35 40 45 50 6 6 12 18 24 30 36 42 48 54 60 7 7 14 21 28 35 42 49 56 63 70 8 8 16 24 32 40 48 56 64 72 80 9 9 18 27 36 45 54 63 72 81 90 10 10 20 30 40 50 60 70 80 90 100 From within 35 42 40 48 Find the diagonal (35 + square, dierence cells, 48) Describe the between inthis (40 what + select any the 2 × sums 2 of square, the for entries example: in the two case: 42). you notice. Suggest a suitable general statement. 1 4 The arithmetic mean of two numbers a and b is given (a by + b). 2 The geometric Choose ve arithmetic the mean pairs mean arithmetic 4 5 6 of of numbers dierent and mean two the and and numbers. geometric the a For mean. geometric 12 Generalization b is given each Form mean of by pair, a a ab . calculate general pair of the statement numbers. c for value n greater a conjecture had below. 1 n = any of than 2, that mathematicians 9. x satisfy the been prove 3 a, 14. sums. multiples can n + integer 2 three integers equation n Suggest which no 1 ATL 1 the successful proof A Andrew found about for trying 358 to years. A LG E B R A 5 Consecutive For integers example, a Choose b For 56 four each are and 57 pairs pair, of whole are a numbers pair of consecutive double the which dier consecutive by one. integers. integers. smaller number and add it to the larger Tip number. Write down the total each time. You c Divide each total by 3 and describe anything you notice. Suggest can GCD(a, suitable general use a b) to statement. meangreatest common Problem or 6 a Choose b For divisor, solving a few pairs of numbers (a, HCF(a, mean b). the common each pair, i their product, ii their lowest iii their greatest and terms ab same common multiple, common divisor, LCM(a, factor your b. The mean Describe what GCD(a, b). general results. you notice. Suggest a suitable general statement. question as 7 Observe that 4 = 2 + 2, 6 = 3 + 3, 8 = 5 + 3, 10 = 7 + 3 and 12 = 7 + the formed 7 is these even numbers have been written as the sum of two Goldbach prime Show that 14, 16, 18 and 20 can also be written as the sum of prime rst 1742. his Determine sum it whether or not the following even numbers can be written of exactly two Although claim has been as veried the posed numbers. in b Goldbach, exactly who two after numbers. Christian a in known 5. Conjecture, All two the thing. statement d of b) The Organize to nd: a c b) highest for numbers primes. 18 as i 30 ii iii 128 iv high as Form a Conjectures collected are in to this believe way, select complex In this take based the based series that of it a on your signicant evidence conjecture a this 2 on more Investigating apply 10 you or will we prove always observations. amount have to observations, will be nd prove to of evidence collected, true. that more Whenever something be the that we we have likely we generalize they have in true. patter ns mathematical are even important – not told what problem-solving what constitutes information maybe , unproven day . techniques to discover patter ns practice is the suggest B. generalization, problem usually that we and statement studied; and Objective: i. are and common, general × it 98 remains c 4 some of you the enough should techniques information collect. you to Choosing used in form how Practice a you 1 start will the help. 12.1 Seeing the forest and the trees 4 57 to Practice 2 ATL Problem solving n 1 Investigate the value Generalize and Investigate the of 7 suggest a n 3 for dierent values of n, where n ∈ n conjecture regarding the value of n 7 Remember 3 n ∈ that means ‘n is a 3 2 value of n n + 3 for dierent values of n, where n ∈ . natural number’. 3 Generalize and Investigate the Generalize and suggest a conjecture regarding the value of n n + 3. 2 3 value of p suggest a 1, where p is a prime greater than 3. 2 Sometimes a general conjecture approach can help regarding us to the solve value of numerical p 1. problems. For example: 2 Simplify 2014 This very is a 2 2012 specic problem 2 it by nding working Look at the and 2014 without a 2012 taken Let n = has then then in this specic nding would Example answer. You could solve the dierence, prove but if you were challenging. 1. 2012 2013 2 2012 2014 2 = (n = (n = 4n = 4 + 2 1) (n 1) 2 Reect In a 2 2014 2 Then it 1 2 Simplify and calculator approach Example and 2 and Example n 2013, then 2014 2n + 1) (n 2n + 1) × 2013 = 8052 2012 n the Substitute 2 What was the specic problem? ● What was the general problem ● How the and 1. brackets. Simplify. discuss solving 1, Expand 1: did n 2 + ● general that was problem problem? 4 5 8 Since 12 Generalization solved make it instead? easier to solve the specic n = 2013. A LG E B R A Generalization C ● How can in generalizations Exploration mathematics be used to solve specic 1 2 2 2003 1 By letting n = problems? 2000, show that you can 2000 6n + 9 write as 2n + 3 2002 + 2001 2 2 2003 Simplify this expression and hence nd the value 2000 of 2002 + 2001 1 2 By letting n = 312, show that you can write (314 × 315 312 × 313) as 2 2n + 3. 1 Hence nd the value of (314 × 315 312 × 313). 2 3 Find a suitable value of 2 to simplify this expression: Tip 2 (507 507 n 1 1 + 508 − 1). 508 Remember Use this to evaluate the ‘Find’ 2 6000 4 Find a suitable this to value Reect ● In evaluate of and the n to simplify the × 6000 expression you 1, how must that show . working. expression. discuss Exploration means 2 × 6001 − 5999 17 999 Use that expression. 3 did using n make it easier to evaluate the expressions? ● Explain how your work 2 in Exploration 1 has also made it easier to 2 3003 3000 evaluate 3002 + 3001 ● Did it matter that we chose n 2000 in 2 n 2003 to nd the value step 1? Could we have chosen 2 2003 2000 of ? + What ● Is dierence there than Although we Exploration way In it can for of to with to the which are pick so For 1500 previous the to the if 1500 1501 a way best of a and and are were in of to a the problem? we If there a might expressions is more picked a To 5999 (e.g. value do and 6000 in expressions understanding (e.g. another the algebraic problem. value one of using better simplies you close each puzzles of attempting 1501, all generalize provide similar multiples to way? evaluated number expression made? calculator, structure are you have easily aid generalize close that 1001, and have it one there the which example, 999, only is simplify numbers n way, could 1 help each easy always one would this of of and n for 6001) a in which made yourself, or this problem. look numbers 17 999). Then nicely. question pick multiples of n = containing 500, because the numbers 999, 1001, 500. 12.1 Seeing the forest and the trees 4 5 9 Practice 3 Without using a calculator, 1 502 501 nd the value of each × these expressions. 5002 × 5006 − 5003 × 5004 2 500 of 2 5 2001 2000 1 − 3 2000 + 4 2001 1001 × 2000 1000 × 2001 2000 × 2001 3001 + 3002 5 3001 × 3003 − 3000 × 3002 2 Generalization D ● What are the risks of in n mathematics making n + n + 1 43 2 47 3 53 4 61 5 71 6 83 7 97 8 113 9 131 10 151 41 generalizations? 2 Consider the expression mathematicians as an n + n + example 41. of It is one quite of the well known potential among pitfalls of careless generalization. 2 The table Verify here that shows each of the the value of numbers n in + n the + 41 for some right-hand values column is of n prime. This leads 2 us to wonder number. On Reect whether the the evidence and expression here, discuss it n + seems n + like 41 a always sensible generates a prime generalization. 4 Prime ● Read about RSA encryption to the right. How many examples are of 2 n + n + 41 generating being prime primes for would use in convince secure data you that it could be used for for numbers very a method What is the smallest positive integer n for which the of cryptography transmission? known ● important rule as RSA fails? encryption. 2 ● Investigate ● Can the expression n + n + 11 in the same way. This you nd any other expressions with similar type of encryption, properties? relies on which prime factorization Given that wonder in this whether Importantly, case generalization generalization generalization is is a has created useful usually skill only at one a false claim, you might of all. part of a mathematical some numbers, underpins our process. modern Once you have formed a conjecture, it is important that you then proceed your claim. In this case, you would not be able to justify the claim data transmission. + n + essential 41 if generating is secure that 2 ‘n methods to of justify truly enormous not is we are prime reliable 4 6 0 prime for to all discover numbers, until it n’, has because new but been it is not true. mathematics, you must proved. 12 Generalization always Forming such bear as in an a conjecture ecient mind that a way is of conjecture A LG E B R A Summary ● A conjecture which ● Once we has a is not a mathematical yet been conjecture usually refer has to it statement proved. been as a proved to be true, ● theorem If the creation the hope you Generalization takes two creation of a conjecture based on Mixed of pieces more general a generalize your layout to problem to form information help in problem you a in a identify table or patterns. If you are of trying to generalize a number a problem, collection to gather logical a forms: ● the of simplifying trying conjecture, other ● are of look at numbers which are similar, evidence or are in the close to being factors of other numbers problem. practice 1005 × 1995 − 995 × 2005 1 Consider the expression n(n + 1)(2n +1) for c 1005 + 1995 + 995 + 2005 dierent positive Suggest a integer values of n 542 × 536 + 8 d value of suitable n(n + general 1)(2n statement about the 540 +1). 5 n+1 2 Consider positive the expression integer Suggest a suitable n+1 value 3 of 4 of 3 for statement about 10 grid contains the numbers 1 to 100: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 the 3 are × n general numbers 10 dierent 2n + Mersenne values A 2n + 4 numbers of the form n 2 1 Marin where n > 2. Mersenne, a French mathematician, n observed is a b that when n = 2, 3, 5 or 7, then 2 1 prime. Verify this Based on observation. this observation, explain why a n reasonable generalization might be ‘2 1 is Pick prime whenever n is any set of ve boxes forming a cross shape, prime.’ example: c Show that this generalization does not hold 74 true for all prime values of n 83 4 Without the aid of a calculator, nd the value 84 85 of: 94 a 2002 × 3001 × 1003 − 2001 × 3002 Suggest a centre the general rule linking the number in the 2 b 1000 3000 (1001 + 1002) boxes Reect and How have you Give specic Conceptual Dierent of added cross to the total of all ve of the together. discuss explored the statement of conceptual understanding? examples. understanding: forms can be used to generalize and justify patterns. 12.1 Seeing the forest and the trees 4 61 for Growing predictably 12.2 Global context: Objectives ● Finding rules ● and and Using describe Inquiry justifying formulae explicit Scientic and (or for proving) formulae sequences technical innovation questions ● What is an ● What is a ● What are the recursive and explicit formulae arithmetic sequence? F sequences recursive arithmetic general and and to geometric geometric sequence? for arithmetic and geometric sequences? MROF sequences ● ● Recognizing arithmetic sequences context in and C geometric How ● ● D How you can you solve and How the does sequence ● recognize sequences arithmetic the to vary common How for ATL can geometric can arithmetic real-life problems geometric behavior involving sequences? of depending and problems? a geometric on the value of ratio? you arithmetic predict in use and future the general geometric formulae sequences terms? Critical-thinking Identify trends and forecast possibilities 8.1 Statement of Inquiry: Using dierent products, forms processes to and generalize and justify patterns can help improve solutions. 12.1 12.2 E8.1 4 6 2 A lg e b r A Y ou ● should use already notation to know how 1 describe to: Write each sequences a down b rst three terms of sequence. u = n the u + 1 v +1 , u n = 5 = 2 1 = 2n − 1 n c w = n ● write recursive and 2 explicit the laws of indices for 3 positive 4, 9, 16, … Evaluate: 5 integer 1 formula for the sequence that begins 1, use , w n Write a recursive and an explicit formulae ● 2w + 1 a powers 3 2 × 5 3 b 6 3 ÷ 6 7 4 1 c 2 × 5 n × 1 5 d 2 4 ● solve simultaneous 4 equations By hand, or using simultaneous y ● calculate compound 5 interest = x Find a General and formulae geometric ● What is an ● What is a ● What are the geometric and the for y value 3 GDC, solve the = 3x of $150 interest invested rate of 5% at per years. arithmetic sequences arithmetic geometric for 6 compound year F + a equations: sequence? sequence? recursive and explicit formulae for arithmetic and sequences? ATL Exploration 1 Here 4, are 7, four 10, 1 dierent 13, 16, 19, sequences. … 23, 30, 37, 44, 51, 58, 48, 42, 36, 30, 24, … 11, 42, 73, 104, Copy each Describe have Suggest sequence any been 135, be ways … … and similarities write down about the anything way you you think notice the about it. sequences could generated. in which the sequences might continue. Continued on next page 12.2 Growing predictably 4 63 2 Here are four 4, 12, 5, −10, 96, 20, 25, 3 Discuss 4 The ways your in 12, … … sequence and anything about Consider in a 17, c 1, e 1, g 64, i 3, 19, 4, 9, , 3, of the 21, 23, 25, 16, 25, … , the way you you 3, sequences notice think with are 2 about the it. sequences have arithmetic are geometric sequences. sequences. sequences geometric 3, following and sequence, … 32, … 18, d 5, … 1, if it is an neither. 9, 10, 13, h decide or b f 40, continue. others. following a might … 48, 3, the 1 step sequence, , 56, step in each arithmetic which conclusions sequences The … similarities sequences The 80, 1.5625, each any … generated. Suggest 5 40, 6.25, sequences. 324, 24, down Describe been 108, −48, 100, Write 36, more 4.5, 20, 39, 5.5, 2.25, 40, 117, 10, … 80, 351, 14.5, … … 19, … j recursive formulae each dene a sequence. A In each case, list the rst few terms of the sequence and determine is it is an arithmetic sequence, a geometric sequence, or a n c e = n is an a When is d. a c 4 b b = 3 4 d 1, e = 1 f g , n arithmetic g = 1 h = the dierence d + 1 between , d f term-to-term formula. 5 + = 1024 1 2)( n = n sequence ( = 1 n + 1 h 1 b n = n 2, + 1 f 1 b + 1 d n n + 1 = n 1 3e = = n geometric working for the sequence with term Therefore the you ratio arithmetic number. could between sequences, The f 3), f n h 6.4, = 5 1 h n = 13.5 1 consecutive constant consecutive we typically dierence terms use a between terms is for constant. the rst consecutive term, terms If d and = a and u 1 u n + 1 = the second = a and 1 The dierence 4 6 4 d is usually called u = u n + 1 the 12 Generalization d the increasing, is negative d equation: u if positive is n it rearranging is series write: u or, called constant. In and , n + 1 g 3, 1 2c + 1 e g + n = n a + 1 c n In = formula sometimes neither. a a recursive if common + d. n dierence is decreasing A lg e b r A ATL Exploration 1 Use the 2 recursive formula to write each of the terms u , u 1 an 2 arithmetic Look for patterns Describe briey arithmetic 3 Now the sequence look as with the how rst term sequence these a and moves patterns common from relate to one what , … u 2 of 6 dierence term you to the know d next. about sequences. for formula. conjecture patterns linking Generalizing for a formula the from for u term the in number patterns terms of to you n. the right-hand observe, This is an write explicit side of down a formula. An is explicit formula sometimes called n a 4 Verify that your explicit formula gives = u a + 6d. 7 5 Use your conjecture to nd explicit position-to-term formula. formulae for these recursive formulae: a s = n b s + 1 t = n + the r to t + 1 2, = t n 4 = 5 1 often represent term s 1 Mathematicians and 3, n the number, use a to represent constant you can ratio the rst between term of a consecutive geometric terms. So sequence when n is write: u n +1 u = a and = r 1 u n or, rearranging the second expression: u = a and u 1 r is usually Looking same called again form as at the common Exploration the formula n = ru + 1 n ratio 1, step 5, which of the formulae given are of the above? ATL Exploration 1 Use the of geometric 3 recursive formula to write each of the terms u , u 1 2 a By sequence considering down a the conjecture with pattern for an rst you term obtain, explicit a and and formula common generalizing for u , the , … u 2 ratio nth 6 r from term it, of write a n geometric 3 Use your conjecture sequences a = c n b + 1 d + 1 described 2c , c n = n sequence d = with to by rst nd term a explicit these and common formulae recursive for ratio the r geometric formulae: 3 1 , n d = 1024 1 12.2 Growing predictably 4 6 5 An arithmetic recursive sequence formula u = with u n + 1 u = a + (n 1)d for + rst d, term with u n the nth a = and a and common explicit dierence d has Sometimes formula arithmetic 1 term sequences are n called A geometric sequence with rst term a and common ratio r n formula u = ru n + 1 , with u n = a and explicit formula u 1 = has recursive progressions, 1 ar arithmetic for the nth and term. n geometric sequences called Example 1 progressions. The An arithmetic Find a are geometric sequence general formula has for rst u , term the nth 7 and term. common Simplify dierence your 3. names are interchangeable. answer. n a u = 7, = 7 d + = −3 (n 1)( 3) Substitute n the given information into u = a + (n 1)d. n = u 7 3n + 3 Expand n u = 10 the brackets. 3n Simplify. n Example A 2 geometric Find a sequence general has formula rst for u , term the 2 nth and common ratio 5. term. n a = 2, = ar = 2 r n u = 5 1 n n u × n 1 Substitute the given information into u 5 1 = ar n n Example 3 n A geometric sequence has the general formula u = 3 × 6 n n a Express the formula in the form u = 1 ar n b Hence write down its rst term (u ) and common ratio. 1 n a = u 3 × n 6 You n are given the formula, but it is not in the form u 1 = ar n 1 u = 3 × = 18 n 6 × 1 6 Use the laws of indices. u = ar n n u × 1 6 n This n is now in the form 1 n b The rst term is 18 and the n The common 4 6 6 ratio is 6. 12 Generalization general form is u n = ar 1 , so a = 18 and r = 6. A lg e b r A Example 4 n A geometric sequence has the general formula u = 2 × ( 4) . n Find its rst term and common ratio. 1 u = 2 × ( 4) = −8 Using the given formula, you can nd the rst term directly. 1 The rst term is 8. Using the formula again gives u 2 2 u = 2 = u × ( 4) = 32 2 The common ratio r is equal to u ÷ 2 r ÷ u 2 The = ÷ −8 = u 1 −4 1 common Practice 1 32 Find ratio is 4. 1 explicit formulae for the nth term of: a an arithmetic sequence with rst term 5 and common b an arithmetic sequence with rst term 4 and second c a geometric sequence with rst term 10 d a geometric sequence with rst term 3 e a geometric sequence with rst term 20 and and common second dierence term ratio term 7 7 4 1 1 and common ratio 4 2 Find the rst term and common dierence of each arithmetic progression. A a u = 3 + 5(n 1) b u n c u = u n +1 3 Find = 2n 4 = −8 5n 4, u n the = 11 d u 1 rst and common ratio of each to is as often a progression. n term sequence referred n geometric sequence. 1 n a u = 4 × 1 n 5 b u n = × 1 7 n 2 8 n c u = 3 × 5 d u n = n n 3 1 n + 3 e u = 0.4 × 10 f u n = 7, u 1 = u n +1 n 2 4 A Norwegian retreating the at length l glacier a was constant of the 6.4 rate glacier km of n long 80 m years in per after 1995. year. 1995. Since Write Use then an this it has explicit formula been formula to for predict the n length 5 of Moore’s doubled a the law glacier showed every Write in an year. 2025 that, In explicit if the retreat between 1965 a 1965 continues and 1975, microprocessor formula for the number at the the power contained of same of around transistors rate. computers 60 in t transistors. a n microprocessor b Moore every two would C later be n years. in Using years revised a How How How law, many in 1965. saying can you in that transistors after did 1971 the doubling law predict would that occur there 1993? arithmetic real-life ● after processor sequences ● his and geometric context recognize arithmetic and geometric sequences in problems? can you geometric solve problems involving arithmetic and sequences? 12.2 Growing predictably 4 67 In this section geometric Example An you will explore progressions can how help the solve general arithmetic = = u for involving arithmetic and sequences. 5 sequence has terms u = 7 and u 1 a formulae problems = 18. Find u 2 10 7 1 The d = u u 2 = 18 7 = common between Although u = 7 dierence is the dierence 11 1 + 11(n the any question two did consecutive not ask you to, terms. it is useful 1) n to u = 7 + 11(10 = 7 + 99 1) nd For the the explicit 10th formula term, let n = for 10 the in nth the term. general formula. 10 u = 106 10 Example An 6 arithmetic sequence has terms u = 14.2 and 3 14.2 = u + 2d (1) + 4d (2) u = 19.6. Find 5 u 11 1 Use u = n 19.6 = u u + (n 1)d to write two simultaneous equations. 1 1 2d = 5.4 d = 2.7 = 14.2 u Subtract 2 × 2.7 = 8.8 Solve the (1) from simultaneous (2) and rearrange. equations to nd u 1 1 u = 8.8 + 2.7(n 1) Write n a general formula for u n u = 8.8 + 2.7(11 1) Use n = 11 to nd u 11 11 u = 8.8 + 27 = 35.8 11 Example 7 The second The common u = u 2 u + term of ratio a is geometric 3. Find progression the rst is 4 more than the rst term. term. 4 u 1 = is 4 greater 1 1 Since the common ratio is 3, u 2 3u = u = 2 1 u u 3u 2 ⇒ than 2 + 4 1 1 4 6 8 12 Generalization is 3 times u 1 A lg e b r A Practice 1 An arithmetic Find 2 An 2 its tenth sequence arithmetic Find its has rst term has second 4 and second term 7. term. sequence eighth term 19 and common dierence 4. You term. could solve simultaneous 3 An arithmetic sequence has third term 11 and fth term 6. Find its equations rst term, tenth term and common or 4 An arithmetic second 5 An term. A geometric A or 9 write of the Find rst the a rst has hand, The second term which term 8 third and 15 and term and term third term value second three times the terms. ninth has is GDC. 16. Find its 22. term 24. Find its third term 48 and fourth term 96. Find its term. D. rst 4th term or second and of of each by a of the must sequence the constant same term of decide By the The equal second are common and than 5th to its both term, 1000. term 16. rst improvement, of The equal the 9th to rst term 28. dierences. situations modelled the Find contexts real-life be 45. trial greater term. real-life should is both their whether term using that rst are and in following scale term. second authentic rst third the mathematics of and nth the 7th 30 the sequence elements you in have the each term for term term Applying whether rate has sequences the sequence, constant the relevant identify geometric sixth expression sequence rst identify To nd and Objective: i. an arithmetic sequence the 3. your term. fth sequence down otherwise, Two term use solving geometric and has has fth and of Determine sequence ratio Problem A and rst value sequence geometric has sequence ratio common 8 the dierence. common 7 Find arithmetic common 6 sequence by dierence. real with life an factors arithmetic lead to or a growth at factor. ATL Exploration Sometimes sequence. described In 1 each You you 3 real-life Consider using case, are an population that next The developers users existing of it of will user for a is a will a the terms save the is introduce by are new a and every by to believe to the it or give geometric could explain money be why. represent. you $10 each to get month. month.) 1.13% factor if would parents pocket trying users arithmetic decide sequence Your your developers 3 the increasing website The of an and sequence, amount increased using scenarios trip. half same Earth new modelled geometric summer have grow. be following or you the will can the what then money The active up and year of down saving pocket problem each arithmetic write started, (Your 2 a 4 of per year. This means 1.0113. predict that how every its number month, of each site. Continued on next page 12.2 Growing predictably 4 6 9 4 The owners customer month, 5 A 20 minutes. after the melts, my the Reect ● ● to this ● will is be a 10 certain has a in has so a out how think their that each business. doubles the work They size of in number the every population every hour 15 you each deep decreases one by chose either of scenarios the need they to real-life ii a be can examples or cm morning. 15% every As the snow hour. 1 that the the resort, coaches starting has arrived, Find ski full coach why is snow sometimes about to year. their bacteria snow of describe in nd trying rst in arithmetic made be in in order successfully Exploration problem that geometric or geometric Exploration to 4. make real-life modelled. How has 4? means i sequence an will arithmetic be sequence appropriate? 8 minutes, 7th it will are the records discuss appropriate, Example arrive the simpler in experiment. depth happened What the others to shop grow Chloroexi house Assumptions problems At of total sequences coee will researcher and Explain new customers of A start Outside a new population 27 6 of numbers at arrived, there some of are number guests equal 08:10, there 920 size ten are stay the minutes 785 skiers overnight during at skiers the after at and day. the the all One resort resort. the other coach skiers arrives opens. After every After the the 10th coach resort. of skiers that will be of skiers that stayed at the resort once the 12th coach arrived. b Find a Let the u number be the number of skiers in overnight. the n th resort after the n coach has arrived. An arithmetic each u = a + (n = 785 coach sequence brings the models same this problem number of because people. 1)d n u = a + 6d 7 Form u = 920 = a + two equations. 9d 10 so 135 = ⇒ 3d d = u = 45, 515 and + 11 a × = 515 45 = Solve 1010 Use the to nd formula to the values nd the of a and twelfth d term. 12 Since b The number of skiers before the of coach is given by u = 515 45 the number of overnight guests is the = guests when 0 coaches have arrived, nding tells 12 Generalization u 0 470. 0 4 7 0 number rst you the number of overnight guests. A lg e b r A ATL Practice 1 Some 3 money annually. 2 of 21 at the years end When it and the one c Find the d Given 16 cm Find the depth a u 215 Find a cm of a rst the pays is compound worth amount ladder’s above the r ungs r ung 20th r ung that interest $29 136.22. of money in At the the end account 11th the rung is 170 cm above the ground. could be expected to form is the at ve 350 a cm ladder the ground and the distance the pool it is water hours it above the ground, determine the total has. constant hours deep of above r ung. swimming rising how is being rate. 19.5 is will cm after take relled After three with water. hours the water is deep. only for one the hour. pool to ll to cm. virus spreads computer every which account next. the top after 25 infected If of number of computer computers is and Determine Each the the the r ungs b A of cleaned, deep is heights to height level the sequence. r ung a a 4 being water account upright, rung the an years year. vertically height that in 20 $29 718.95. 30th 14th of of worth why from The end arithmetic Find After invested the its number 3 is of Explain an b is the standing ground a At via emails from successfully an infected manages to computer. infect ve new day. represents the number of infected computers at the star t of day n, n explain why u = n b c 5 Given number the star t seats 19th In the If it of what arena by the 95 computers from infected which the at vir us the was star t of initially day 5, nd launched at 1. an has 2592 computers day on n are day are same seats. the vir us arranged number so of Determine will infect that seats. the each The total the millionth row 13th number is longer row of has seats computer. than 71 in the seats the row and front the three combined. 2014 doubling a in of row rows 6 of Determine front + 1 there the The in that 6u u Ebola every outbreak, month represents from the the number April. number of In of June deaths n deaths there from were months the 252 after disease was deaths. April explain why n u = 2u n +1 b Find n the nding number the c Find the d Explain number why continued of number this of deaths of deaths model number of in deaths April in from does deaths and any Ebola not over fully a write month in an after formula for September. explain longer explicit April. the period outbreak of and the time. 12.2 Growing predictably 4 71 D When do geometric sequences defy expectations? ● How the ● does value How the of can you sequences behavior the to of common use the predict a geometric sequence vary depending on ratio? general future formulae for arithmetic and geometric terms? ATL Exploration For each of the a nd the b describe c predict 5 sequences rst ten what what described terms you will of the notice happen in steps 1 to 4: sequence about the to value the terms of u , the nth term, n as n becomes very large. 1 A geometric sequence, rst term 10, common ratio 2 A geometric sequence, rst term 10, common ratio 3 A geometric sequence, rst term 10, common ratio 4 A geometric sequence, rst term 10, common ratio Reect and ● Compare ● Do the discuss and same for Exploration A sequence Another For in 1.2 1.2 2 the those 0.8 geometric steps 3 and sequences in steps 1 and 2 4 6 terms sequence each a has contrast 0.8 10, has 10, terms 10, 10, 10, 10, 10, 10, 10, … 10, 10, 10, … sequence: determine whether or not there is a common ratio between successive terms b explain Reect whether and or not discuss it is a geometric sequence. 3 The 0, ● How ● Is would you best describe the behavior of the if sequence you try before to 0, nd 0, the 0, 0, 0, … common a geometric ratio by sequence? dividing sequence 0, 0, any What term by happens the term it? lot with in common sequences is depending closer to on the zero. innitely between sequences If large. being 4 72 r either common is greater When r positive become ratio. than If 1 larger r or is negative, or negative. is 12 Generalization larger between less the and than terms of 1 1, a or and the has geometric not smaller 1, the terms geometric and values will smaller will get become sequence alternate as geometric of the but normally regarded Geometric … sequences? a the 0, because problems involved dividing with by zero. A lg e b r A Summary ● ● In an arithmetic sequence the A geometric common between consecutive terms is = ru n +1 An arithmetic sequence ratio r has with rst recursive term a and formula constant. u ● sequence dierence with rst term a , with u n = a and explicit formula 1 and n u = 1 ar for the nth term. n common dierence d has recursive formula ● u = u n +1 + d, u n = a, and explicit In a geometric cannot u = a + sequence, the common ratio, r, formula 1 (n 1)d for the nth be equal to 0. term n ● In a geometric consecutive Mixed 1 An a terms is the ratio between constant. practice arithmetic Find sequence the sequence common begins 7, 25, 43, 6 … A geometric a dierence. Write down common b Write nth down term to a recursive the (n + formula 1)th linking Write nth down an explicit b formula for the begins value of 6, the 42, 294, rst … term and the ratio. the term. Write nth c sequence down term to a recursive the (n + formula 1)th linking the term. the c Write down an explicit formula d Find the value of the fth e Find the value of the rst for the nth term. term. d Find the value e Find the term of the 15th number of term. term. the term term to exceed with one million. value367. 7 2 An arithmetic sequence has fourth A a 253 and fth term geometric Write down begins 6, 3, 1.5, … Write down the value of the rst term and 291. the a sequence term the value of the common dierence. common b Write down a recursive formula linking the dierence. nth b Hence nd the rst c c 3 Find An the sum arithmetic sixth term common of the rst sequence 52. Let the dierence has rst be three terms. third term term be a Write nth 31 and d and a two the down the three A simultaneous equations in terms a nd a, d and the value of the 10th An arithmetic sequence is it 91. is Find The the has product value of of the the rst rst two third of an second Write term down Hence term, given c that Find arithmetic sequence is rst term. The formula for the the tenth term, correct gures. second is 9 has common more than ratio the 4. rst term. term two in dierent terms of expressions a, the rst for term. write an equation term is and nd the using this value of a how A many that geometric terms are less sequence there than has are in the 1000. rst term 12 and twice third the of sequence sequence term explicit terms negative. The term. common 9 5 an value information dierence6. 1)th term. b 4 + of andd Hence (n signicant geometric second b the d The Form to term. Find to 8 a term term. term 48. The common ratio is r 45. 2 a Find the common value of the rst term and a Show that b Hence dierence. nd common b Determine of the whether sequence. or not 310 is a r = 4. the two possible values for the ratio. term c Find the possible values of 12.2 Growing predictably the sixth term. 4 73 the Review in context Scientic and technical innovation 1 Consider the illustrates ethane following the and chemicals diagram, chemical propane, known as which structure three of b Determine methane, examples of c the C C C H H 3 H H ethane that the H H b Let u pictured be the this have model at the how predicts the for many end of members the this second model year. A design by an forms number of produces business cards. charge a set the cards in boxes the same amount. fee for of 100 design, cards. and Each then box sell costs hydrogen H) an of company H propane number atoms(represented alkanes to 12thmonth. Determine They methane Show members website C H a of the C H C end many for H H H H H predict alkanes. H H how would in the hydrogen The three arithmetic atoms total cost 400cards sequence. The in is total (including the design fee) for the design fee) for $108. cost (including n an alkane down an with n carbon explicit (C) formula atoms. for u 600cards Write . Find n the design c Find the number analkane with of 20 hydrogen carbon atoms is $133. cost Find the number of carbon 4 atoms in A with 142 hydrogen machine The developers of a new social the same that scale its membership end of the rst and at the end factor month of the it every has second the produces per a hour, constant except in number of the hour rst the end of the second hour of operation, it media will made month. 20 000 At it components. By the end of the hour, it has made 24 000 components. the members, month 6000 grow seventh by calculate atoms. has websitethink and operation. By 2 cards, an of alkane 1000 in atoms. components d for fee. a has Explain by the why nth the hour number forms an of components arithmetic made sequence. 25 000members. b a Explain above which suggests information that this can in the be statement modelled rst geometric number Reect and How you Find the number over a dierent products, 4 74 components made in of components made in nine-hour discuss explored the statement of inquiry? Give specic examples. Statement of Inquiry: Using of sequence. total have the hour. with c a Find forms processes to and generalize and solutions. 12 Generalization justify patterns can help improve working day. the So, what do you think? 12.3 Global context: Objectives ● Selecting Inquiry samples and making inferences ● about F populations ● Identities Understanding the purpose of taking a sample ● Understanding dierent sampling when it is questions What are the dierent sampling ● How are conclusions experimental drawn from data? techniques appropriate ● How ● Do ● What to do we know when to say ‘when’? D generalize ● from Understanding reliability ATL of a sample the your eect to of a population sample size on the the generalizations want eect to follow does reliability of the sample our crowd? size have on generalizations? Critical-thinking Recognize unstated assumptions and bias 4.3 Statement of Inquiry: Generalizing trends you and among representing relationships can help to clarify individuals. 12.3 E4.1 4 75 SPIHSNOITA LER Using relationships methods? C ● and Y ou ● should represent already data stem-and-leaf using how both diagrams box-and-whisker know 1 to: Below and are the customers diagrams bar over Present leaf number per the this day course data represent data frequency using cumulative 2 diagram. 54 77 71 73 89 55 17 53 70 75 88 29 34 33 67 71 55 50 Represent the people many same made radio their shown ads here. note they the for a mean set of and the 3 in calculate the interquar tile range range and for a set 4 7 5 < t ≤ 9 14 10 < t ≤ 14 10 15 < t ≤ 20 3 21 < t ≤ 25 1 heights school of The ● paper on 4 7 6 we we background if need What things deductions of boys football as data. (in meters) team were follows: 1.55, 1.64, 1.49, 1.72, 1.81, 1.73, 1.68, 1.75, 1.70, 1.69 the mean Calculate the range. Calculate the lower and interquar tile example, this ≤ quar tiles Some heard and 1.58, median heights. data F how cumulative t Calculate of a Frequency measured ● a from < a on work, 1 The data of had to Create graph Ads median data diagram. commute frequency calculate days. stem-and- 19 on ● noodle 20 65 35 graphs a of a of in box-and-whisker ● at are learn draw the from walk each to into desk, range. draw a we have. conclusion classroom might methods? experience, evidence your you sampling rst-hand the upper the sampling dierent from knowledge you for and hence infer 12 Generalization is and that while Using known your you others based observation as inference. teacher were are has having an on and out infer draw For laid To based a sheet assessment. or means to conclusions on evidence reasoning. S TAT I S T I C S Inference The in in Moon 8 Key : 7 two High at for shown in two the School 4 4 5 4 3 5 4 3 1 6 5 3 3 2 0 0 7 2 7 8 4 2 1 8 0 3 5 5 8 9 5 3 9 1 2 4 4 5 8 8 1 10 4 4 6 7 1 11 3 81 for Crescent discuss stem-and-leaf Moon and diagram and Did you come up with any answers ● Did you come up with any conicting conclusions do is to your the specic dicult between one don’t dicult to have or process of it. and of know and anything Oyster Bay the performance of the and about those that the data of they data? others? did not? conclusions? about general eAssessment because such might the about discuss the median the following of students Crescent The In this as you time explain are spent the characteristics scenario, given on it’s so little revision, dierence in personal performance other. conclusions Which at on conclusions the size based from factors, class the Calculate at score quality any about or the underlying the school, nature trends. or the of In the data, this students, case, it’s you which were did a 2 for the statements Oyster Moon teacher Crescent ● teacher here. unrepresentative. Reect The dier from conclusions reached draw drawing Various even school draw you information. inferences about circumstances, can conclusions pieces make information ● for compare ● ● same 1 How unfair 85 the diagram Academy 6 ● may Bay 8 What you where 9 ● from schools stem-and-leaf Oyster 7 and the results are schools. Inference If years 1 | 8 | 5 means Reect Look eAssessment consecutive Crescent P R O B A B I L I T Y statistics mathematics taught A N D Bay classes do from you Academy the think are more two are schools. justied? intelligent than the students High. better job of teaching the class at Oyster Bay than at Moon. The class Bay class. at Crescent Moon scored lower on average than the Oyster 12.3 So, what do you think? 4 77 Again, it’s dicult performance, data. The average, even you only the this is don’t Even High’, it A is if you the might It is not of set be they of a be sat the agree the of than was the the rst based the the or a of is in surrounding saying Oyster Bay dierent ‘The students statistical on teacher’s that the on class, years but and same. a at students Crescent inference sample consideration people, the factors statement: than Specically, under the eAssessment tests with compare condent lower intelligent objects to about really population group or enough scored inference. of a can class more about a could we since are example population that schools, know standard Academy an the don’t Moon problematic, conclusions context. we statement know Bay drawing compare Crescent though Oyster to because in collection is from a of the that at Moon action of population. statistical Any objects. set could of objects form population, A sample is a subset of a on a is the act of drawing conclusions about a population based of sample. sugar sold and discuss you believe would you A census A sample that Often it a identify to will everything is the D. taken like 1 know the at data if one such from its in another justify school school. a are better What sort at of evidence claim? every properties draw two the of member reect not range your nd of the in key the of a those population. of the population to a census. population. be is the representative only to situations help answer even the when questions you don’t in know skill 1 a it large about might factory, the not which has commuting be sensible around times to ask of 10 000 their every workers, 12 Generalization would sta. single employee. Continued 4 78 It In contexts assumptions mathematical the would real-life knowledge conduct of school. real-life authentic general a sample within underlying is practical representative mathematics context more why to is is schools, ability on it sample elements Trying about Explain of a Applying managers to to because that whole to 1. students from. Exploration The collect representative ensure need the students collection relevant Exploration that the concerning covered You a is to Objective: i. is sample example it need comes important if than on next page all in 3 2014. mathematics bags lled by could population, could Suppose the machine a Reect for population. example Inference a the as cars Japan a be in S TAT I S T I C S 2 The managers They decide brainstorm They could ask each b They could put up c They could ask one d They e They it They would times be it of the There are rather than as you You if will is In a we a case would methods all ● A ● A other A stratied the department respond to at by estimate work. email. an average sta list, having person on the company’s sta list, having that name Explain into a bag how useful information is a list and you draw think about to sampling sample sample an of sample those with the out the the surveys commute above If, is that the survey and can idea required known every of a sample, practicality. arise of as when bias. having a A member the probably a There taking sample of it the is is be of all the frame. population. quite company not list sampling employees, however, would a cost population. list able likely wished to that to obtain a run list products. member available a to sampling of us the population. depending frame. The on whether following three it is sampling frame. is the takes sorted do surveying every likely ordered list they are of list. their obtain to identies a are problems This are conduct which samples we of might of 1, are not. that bought equally a the such methods from from ensures to arrived company’s two these did list member systematic person they information. the company survey, random is a of obtain a ideas. where had require any as employees. the on representation any practical, intervals ● is to of others frame population of the person Exploration some one, who simple of gathering employees each representative why in fair sampling or sample of individually employee’s workforce, satisfaction possible, a employees. Most that this sampling Dierent a able everybody A seen frame be customer of not like in of ways department. 200th these out reasons whereas sampling for asking 200th every of whole notice survey random. each have employees, A put at however. it that every factory’s the notice person for a ideas salary. nding good sample, biased on a of employee every ask by could for conduct P R O B A B I L I T Y alphabetically. 50names Comment ask could sorted f time could sorted a to number a commuting are, a A N D a to sample be such included that in every the member sample, of the independent population. members sampling of the frame population – e.g. taking at regular every 10th alphabetically. identies groups are dierent sections represented in of the population appropriate and proportions in sample. 12.3 So, what do you think? 4 79 Simple When make or by random creating are using the systematic having frame rst at form that of a you this to you or reected a is formed random sample, represent. might or that ‘fairly want generator by taking starting important done on an point to the the make age sure ranges proportion in the from a have means proportions students rst example, represented’ proportions 10 you For dierent match that the Sur veying is be of that pulling the selections names from a you hat calculator. ordered sampling – taking items to divide the of if that frame from the and then – sampling in in 80 after an IB exam population surveying and fairly the men people were men were that of you women proportion the a into groups group were fairly represented. of men population, dierent age in and ranges the likewise in the of the for sample population. year 10 You group a by intervals. stratied should women; number it could sampling case, sample sample picked represented, In sample This sampling want people, random random. random regular Stratied To simple genuinely Systematic A a samples to are 1 = sampling 80 see 8 students. how dicult they thought it was. The 1 From students were taught in ve of 16 2 20 of the cars in a full meet cars to see regulation whether their were requirements. compacts, 250 cars class, 2 you need of pick a simple random students. 20 1 = need 500 tires of the cars. 25 1 100 So cars of lot You 500 16, students. each sample of of students. From Checking class 8 16= classes each dierent you need of 100 = 4 compacts; 25 were 1 estates and 150 cars were saloons. of 250 = 10 of 150 = 6 estates; 25 1 saloons. 25 Pick the of Reect ● What and are sampling ● Suggest the discuss advantages described some a simple random compacts, the 10 of sample the of estates 4 of and 6 saloons. 4 and disadvantages of the three types of above? situations in which you would use each of the sampling techniques. ● Describe 4 8 0 the diculties you might 12 Generalization encounter when trying to apply them. S TAT I S T I C S Example Javier The going are 60 to year and how a simple b a systematic c a stratied a Method up students provides a list each at of with his the school. 500 100 total students students, and in each the year school. group girls. could create: sample sample sample. 1 printed its Method list contents to separate and then all the names randomly draw and out place 50 them in a bag. names. 2 Number number 40 random a Shue 50 groups, Javier a Cut sample secretary ve boys Explain P R O B A B I L I T Y 1 school There has is A N D each student generator to from pick 1 50 to 500 in numbers alphabetical between 1 order. and 500 Use a random (ignoring any duplicates). b List the students generator point, to take starting in pick every a alphabetical random 10th Each group of You are You can students. year group get random From back number that to 50 students out of a total of 500 the means taking every 10th name. of the school, so each group should be a 5 Within take a each simple group 60% random are boys sample of and 6 40% boys girls, and 4 so girls. 1 concerned contents. a 10 each Practice 1 point. you a 1 = is 500 from until Use point. year sample starting name 100 c order. tell If Explain if an the that egg egg is is the eggs rotten rotten, why you might how you could in by there wish your kitchen breaking will to be it a sample are open rotting. and pungent the eggs, smelling the smell. rather than conduct a census. b Explain conduct a simple random sample of the eggs. Tip 2 Alex lives in a high-rise apartment building containing 80 apartments, There ATL numbered 1–80. He wants to conduct a survey to nd out how many is relevant on average live in each information people to situation a Explain how he b Explain why a apartment 3 could create systematic and then a simple sample selecting of random 20 every sample apartments fourth of 20 starting apartment apartments. Describe any factors stratied sample. that would be relevant if Alex is not within the question. the design Could with might wished that contained lead to to take a of the bias. building c the apartment. be relevant here? 12.3 So, what do you think? 4 81 3 A teenager He sends a Determine Comment 4 A full b D 80 320 E 240 160 of A in at has on his phone. been made is available as for pay grades. follows: a survey on work. the company could construct a simple random the company could construct a systematic the company could construct a stratied sample of how sample of how and of of women’s students it would scenarios people in a supporters they the at school of thought voters in a civil training a be it sample necessary would random to nd big your to of combine pay be from out a the possible to sampling proportion conduct frame. of students wish of have know could of views to you people people is in as to who hockey was town to doing see if team a to good they nd out job. would vote in mayor. in frame what decide the manager an American cannot sampling as ice city to see if they attended regularly. sample subgroups until You sessions quota particular particular town sampling responses, a the servants the where only 4 8 2 selecting of representative questions why following the how you by not dierent town. the re-electing possible Suppose of the of safety into clearly B. the of or survey decide Explain vegetarian. survey situations be how sample survey guarantee your employees which are to means the provision dierent grade 30 In split on pay 40 survey re rst each C favour A employed at cartoons. list method. 15 whether d sampling 12 employees. who A people, women watch contact is. B random c this friends the 2 list Explain A 900 and this in 1 grades b men of his employees. 90 A suitability employs of sample of person A Describe a the of many 20th employees. 45 a sort how every Women Describe c know to Men Describe 40 to grade childcare 5 on number Pay a what company The A wants message to is be. local who as live equally. 12 Generalization desired, in To the sampling. needed 30 locally, obtained, used. shoppers survey live If stratied many be often and town, want to is a you possible can sample, still data be by any quota. public want so not quota collect your of You it sample Then ll think people. your to or create transport your are represent in sample going men’s to to ask and S TAT I S T I C S An appropriate area and received ask way the to rst responses conduct people from 15 the that survey were local men might willing and 15 to be to talk local stand to in you. women, the P R O B A B I L I T Y downtown When you A N D you can have stop. ATL Reect ● Why and might important ● A What It sample Identify Give as a b You want c You want botanist group in school An A One and event is Describe a A to are a as her d a conduct on the taking frame enough to to is pieces a the survey quota sample? unknown, of be survey)? data or are does not found. Explain assess the mark of to in your want nd of the the following to 20 the leaves school obtained sample scenarios. by collect travel a in 30 time a type school in everybody’s and average to students employees sta on tree. each your day. year scores. school facilities taken of by which sta. runners to race. the on and satisfaction plans form are in by sample the with their latest style of proposed. the form random to box for every product that is sold post. of customers guarantee disadvantages estimate and a a He records She of to based registration of their 150 average the 25 their of his the on the forms. plans. Determine whether her heights of random the MYP heights height members of of students his correct to in school the his year athletics nearest cm. sample. estimate uses suitability simple the uses suitability wishes the group how at administrative dierent a length customer return records how 20 to charity lled group. on mean don’t wishes students. on each samples. student year but wishes call for students feedback sample and Explain year a wishes 150 Comment this to the average advantages year sample c when sampling until method how test, Some put is nd the km numbers Another in 10 to Comment b the data to possible. teachers, wants student team to organizer the of as nd random group stand inuence encounter when out recent plan telephone 3 nd customers Another they to machine. plan ask you unwanted sampling detail 150 company coee used principal complete 2 where you collecting wants a employs e of have might suitable much A A 5 2 a d choice thus is involves Practice 1 the (and problems quota exist. discuss average History correct her to height class the of of 25 nearest the 150 students students as a cm. sample. sample of 25 students could be taken from students. stratied sample of 25 students could be taken from this group. 12.3 So, what do you think? 4 83 Generalization C ● If a How sample proper ties you can is use sample about the conclusions representative should the population. the are In reect proper ties doing data you whole average She thinks than The a The 188, have the of of the to and from using – to make year drawn, means about its that the whole knowledge broader from conclusions each 16 have 181, the of the other 192, the 8 boys boys from heights, each 181, 192, following 194, school rowing 180, 174, on 157, of the rowers. 2 Calculate the mean height of the non-rowers. 3 Comment claim than that the boys rest taller on of who their make year team, and to the nearest 182,179. 170, 193, height her are group. measured mean on rowing year 184, heights: 167, the the the average team group. Calculate on is specic make 1 taller it This deductions taking it data? which population. make generalizing following 173, 187, who their height students 167, are of sample obtained of sample centimeter: other 190, you the experimental population proper ties of boys rest the random rowers whole the from 2 that the measures takes so, have drawn inference population. Exploration Antonia of the and 154, 192, 165, 168, 165. the school rowing team are group. ATL Reect ● Where ● Is ● In the and have discuss you generalized generalization this problem estimating the sensible use to 6 you the Exploration 2? reasonable? have mean in of used the range of the mean population. the sample of a sample Explain to why estimate as it the a way might range of not of be the population. In this context, information from which could these draw you gained it should from came; second, conclusions generalizations 4 8 4 have the that about are made sample types by generalizations: you something comparing which of two told group inference. 12 Generalization the means contained rst, about of taller that the two the population groups students. you Both of S TAT I S T I C S Practice 1 Your in subject 2 says that your Chemistry. are test Your presented in scores results this in (out Physics of 100) are for better the than last six your tests 64 66 58 72 81 Physics 64 62 72 73 60 70 Calculate your b Comment c Explain on how suspect mean your you that test score tutor’s have boys in Chemistry and in Physics. claim. used are each table: 56 a test in Chemistr y You P R O B A B I L I T Y 3 tutor scores A N D generalization spending more in this money problem. than girls in your school ATL canteen. You spent the stand by the cashier one lunch time and record the amount Tip are by as rst ten girls and by the rst ten boys. The amounts you record Why follows: does appear Boys Girls in the so $4.00 frequently table? Something $3.12 $1.00 $4.00 stands $4.00 $6.37 $1.37 $0.88 $4.00 $4.00 $4.00 $4.00 $5.16 $3.82 $4.00 $4.80 you the $2.32 Describe the type of sampling Outline one way in which this of sampling might have Comment d Explain from have, question it an is likely impact the validity of bias. the c you have on introduced infer then whether used. manner what $3.55 to b on this you information can data and a like cause reect other $3.65 out should to $2.13 that $2.51 on the where Exploration claim you that have boys spend generalized in more your than girls in the sample. canteen. answer. 3 ATL GDP GDP per capita is a measure of the average income per person in Gross country. You can nd this data in annual tables in the World stands for a Domestic Bank Product. database (data.worldbank.org). 1 are There to select the 2 GDP Calculate whether 3 a a large number sample. per capita the it Determine mean rose if the whether would it how of a GDP the the be your countries years per better results of to 2000 capita use a compare in this to you for table need so of it help will 10 be with this. necessary countries with year this and determine 2010. made the stratied using you 2010. each 2000 if sample and for from countries per teacher random capita period GDP your simple the selection about see for over generalize and Make Ask is whole fair for world. sample. Plan you to Explain how to do this method. 12.3 So, what do you think? 4 8 5 Exploration A factory number owner of components they each the output produce per of two day is employees. recorded for The ten days: 101 100 99 93 108 100 106 90 95 Employee B 116 102 100 98 86 116 100 112 80 90 Present each 3 If the factory Why ● What ways of Bay it back have the Crescent at Moon (the range is data is the High box-and- keep employees. only one of keeping. the two Justify employees, your decision. to comment be considered are you on the in this mean a able consistency positive to of his context? attribute? calculate that describe how is? the range a and set of interquartile data is packed range are together appropriate – how the is how What 41 for suggest within Crescent be Crescent as a range that Moon compare range at and and High School the location interquartile Oyster marks Bay High in measures together. been of and of the range spread 12 Generalization have should here observe consistent. outliers, – so that was Oyster data tell you IQR rather try than marks at Oyster statistics the consistent, or variety. than whereas smaller of that greater the 19.5. Academy say more always the pairs Bay might showed range Both Oyster You comparing by You done should at 16. Academy School aected interquartile range interval. interested has you 67 the smaller easily your smaller, more is packed data might the interquartile Moon more range if you do has and students densely of at School IQR) will data data? range the the were 4 8 6 the however, IQR Academy of at you more context that as looked the of because general, side-by-side 477). together results general, this you densely median. has and performance the two 7 eAssessment the spread grouped data such to two recommend measures of how (page already Academy that set the Bay are using is. examining about a the ‘consistent’ consistency spread Academy You asks does of able would owner statistical of was discuss comparing consistent Look you What might consistent Measures owner and employees. ● production performance which Reect The the factory suggest ● employee’s diagrams. Compare the compare 108 2 In to A whisker In wishes Employee 1 by 4 the the IQR values, to range; is then interpret saying Oyster this outlier piece the simply Bay An not. lies in of far overall pattern of the is data a that outside the distribution of the data. rest S TAT I S T I C S Practice 1 A N D P R O B A B I L I T Y 4 Joe can bus journeys travel diagrams to work and 40 by bus train or by journeys train. are The total illustrated journey in the times for 40 box-and-whisker below: Bus Train 0 20 30 40 a Determine which mode of transport is b Determine which mode of transport has c Explain, the 2 10 Two bus with than computer messages. The speed be The can times reference the these a statistics, on average. more why predictable Joe might journey prefer to time. take train. scientists two write programs assessed. taken to faster 50 (in Both programs (A and B) programs seconds) are as designed work are in to crack dierent timed for encoded ways, decoding and 11 so their messages. follows: A 12.1 11.8 12.4 12.3 12.5 12.1 12.1 12.5 12.1 12.3 12.5 B 10.9 12.4 14.2 13.2 13.7 14.4 13.3 11.8 14.2 13.8 10.8 a Determine b The program decodes you which a is new would program to be used message choose to is in the use faster a on coding fastest under average. competition. will the win a following prize. The program Select scenarios. which Justify which program your answer. i ii iii 3 In to You are 12.5 seconds. are 11.5 seconds. You are a factory, them taken grams, the last You ll are the the Machine A Machine B rst two to a from are last as programmer to compete and the current best time is programmer to compete and the current best time is programmer machines weight each of and are used 1000 g. their to compete. to To ll sugar compare contents bags. the weighed. two They are expected machines, 12 Theresults found, bags in follows: 995 1009.5 999.6 1005.3 996.7 991.3 1022.3 1005.9 a Find the mean b Find the interquartile c Compare the weight output for each range of the for two 997.1 1000 999.5 1005.4 1002 994.7 1002.4 1016.2 1005.2 1001.1 994.7 1000.7 996.2 1010.1 1009.6 1005.3 machine. each sample. machines. 12.3 So, what do you think? 4 87 The D eect ● How ● Do ● What do you we of know want eect to sample when follow does to say the sample size ‘when’? crowd? size have on the reliability of our generalizations? In by spite of using chance, reliability end of a sampling up being sample Exploration 1 Use a integers Microsoft random 2 Select 3 Calculate 4 Collect and the class the the Predict sample is a Given that value, why the the sample that may aects still, the a list of 400 randomly 20. Sheets and 20 is the command to generate ‘=RANDBETWEEN(1, from this a 20)’. list. sample. that have stem-and-leaf been calculated diagram and in then your class present the data diagram. using a sample members estimates mean size of the of class estimate we 20 instead of 5, gathering have found dierent values explain A manufacturer ● A marine wants biologist dierent a be large the the two would for the sample mean produce small taking to of for size sample have on sizes. the of whole or the the set of mean data. of a small population. 8 wants areas would for use why sample found. of sizes ever diagrams the value mean sample ● in generate numbers means a discuss would and 5 varying the better larger the factor before. eect and care, mean. whether Reect 4 8 8 in of 1 box-and-whisker of what Suggest and your dierent what consistency crab of experiment as 1 to Google sample sample data why Compare scenarios or GDC between them sample Suggest 8 between mean the your box-and-whisker Explain for 7 a Repeat your 6 all great Another size. Excel random the its or integer organize using 5 a with 5 spreadsheet selected In is techniques unrepresentative. large know to the less variation samples? samples long study their the might light mass Mediterranean 12 Generalization in the Consider of be bulbs a the estimated problematic: last before particular Sea. mean following failing. species of S TAT I S T I C S A N D P R O B A B I L I T Y Summary ● A population is consideration be a group of a in set a of objects statistical people, or a under context. collection ❍ It could of A stratied sections objects. those the groups proportions ● A census member ● A is a of a sampling the collection of data from population. frame is a ❍ list of every ● member A quota frame of It population. A sample ❍ A is a subset of a is representative those of the if its population properties from which is ● simple that random every equally sample member likely independent to of of be the is a other sample population included any A sampling Mixed Tom is 13 sample in the ❍ sample, member of sample takes regular intervals at the the data is are biased is of does data the not sampling exist. until enough found. the if the act population can use mean Larger members from it is not a fair population. of drawing based on conclusions a sample. of the a sample mean to estimate population. samples provide more reliable of the the Jo are comparing the IQR The for their IQR Jo’s marks for marks in Tom’s is 18. recent 3 marks Tom Paul sh because his IQR is smaller he has in the assessments. Jo says that is larger she has performed in a to estimate the average length of the lake. knows that roughly 40% of the sh in the performed are salmon and 60% of the sh are trout. because To IQR wants says lake her or collecting when frame. assessments. and better a You He that used practice and English is estimates. systematic population that appropriate such is ❍ A of Inference population. ❍ ensures in sample. unknown, involves about A sample representation it comes. ❍ and represented the dierent population. ● sample reect population are in identies every pieces 1 of sample better in measure the sh, he will catch them with a the large net and measure them on the shore before assessments. returning Comment 2 A school’s mean of on ballet height 21 cm. their of The claims. class has 1.51m sample 11 and school’s a students, range chess club of with a a heights also range of with heights a mean of height of Comment to of on the 1.73 m the 4 dierences of between the Explain A polling to chess ballet Explain the c why data Claire it would proposes adult clubs suitable sampling method for how he would take such a a Paul sample. company would the like to conduct extent to which a the of a city feel that advertising. they The are subject company to proposes range be preferable rather than to the know phone a to use the concerning chess may simple directory random as a sample sampling using the frame. range the company’s plan. sets. predictions and take to club. interquartile the to and Evaluate of plans the class conduct b He 50. determine unwanted the water. anda 43 cm. members a the use. residents heights size Suggest survey a of to has b 11students, them not adult players. be a data to ballet Explain suitable make dancers why these sample. 12.3 So, what do you think? 4 8 9 local Review in Identities 1 The and average neighboring random context relationships household towns sample of is income assessed residents in by two a taking using a a as a sampling frame. The the as with box-and-whisker data diagrams. Describe the the similarities two sets of and dierences data. follows: c Income range ($) Town A Town 20 000 ≤ x < 30 000 4 1 30 000 ≤ x < 40 000 7 4 B Comment education d 3 Evaluate You will be on 40 000 ≤ x < 50 000 11 ≤ x < 60 000 eectiveness the authority’s able to of nd 15 6 from the (www.ipu.org) 60 000 ≤ x < 70 000 5 12 70 000 ≤ x < 80 000 4 9 the x < 90 000 4 Take 5 ≤ x <100 000 0 3 0 1 a from ≤ x < 110 000 b Present of this information cumulative frequency that the the national World You the varies random countries Compare 100 000 about method. parliaments in are to Bank investigate percentage dierent Union of women’s continents. 7 a 90 000 in Inter-Parliamentary or proposition representation ≤ the sampling data women (data.worldbank.org). 80 000 of intervention. 7 online 50 000 the authority’s representation a over-and-under obtained between is data recent b census Present using a graphs pair on the Comment stratied from Africa, means on of whether representative of the sample Asia these the data of and Europe. samples. samples in this are case. the c Describe how you would take a census sameaxes. from b Comment earnings on of the dierences households in between towns A the and The statistician that the samples towns they by word the conducting are came the survey representative from. Explain representative in of what this claims the is data to meant Elderly people number with of were hours, volunteers assistance t, To in assess 50 the primary authority of schools, assesses 11-year-olds after impact in the three the a new local reading of implementation. summarizes a the The the the three surveyed of after average continents. social the about contact the they introduction of have a new scheme. context. Hours 2 compare from B. 4 c this representation literacy Before After strategy education age of schools before following 0 ≤ t < 2 4 0 2 ≤ t < 4 10 8 4 ≤ t < 5 7 9 5 ≤ t < 6 5 8 6 ≤ t < 8 6 5 all and table data. Before After Minimum 8.4 8.2 Q 9.2 10.3 10.1 10.8 10.5 11.1 13.2 12.8 8 ≤ t < 10 4 5 10 ≤ t < 12 3 2 12 ≤ t < 16 0 2 16 ≤ t < 20 1 1 1 Q 2 Q 3 Maximum a Interpret not 4 9 0 12 Generalization the the data scheme and was suggest successful. whether or S TAT I S T I C S The sample details waited who for in he would was 40 the local thought be obtained elderly bus were interested by collecting people. depot over in The and 75 such a contact You researcher asked whether scheme believe depending people grew they up country, or he could have their contact the success of the Determine c Evaluate d Suggest the the a type the research parents sampling used. dierent methods. appropriate way b You want more to nd likely sample. out to if to in local, Outline your obtaining reliable data a whole donate You to is year, a the to you expect relevant to form easiest give which money give take that data family the country. up that 30% locally, of 45% families grew country and 25% grew up in you would your use sample Reect and How you this information a year, you with receive parents 40 that responses grew up from locally, from those that grew up elsewhere in the or and 50 from those that grew up in a to to country. encounter your Calculate way people they can to collect forms ll in the number of responses you inquiry. to in keep when for use order sample to from each obtain the category largest of respondent representative possible. they charity. to every student in your school discuss explored the statement of inquiry? Give specic examples. Statement of Inquiry: Generalizing trends and among a representative. home. have up causes. diculties decide the make should You in school national c in in to dierent a dierent vary the country. how try country international a elsewhere suggests grew to After students donate in in of 75 are that Explain families 5 up will parents scheme. researcher’s more constructing of grew up trends to elsewhere b grew the P R O B A B I L I T Y and details had evaluate donation whether locally, Separate whether that on A N D representing relationships can help to clarify individuals. 12.3 So, what do you think? 4 91 13 Justication Valid reasons or evidence used to suppor t a statement Verifying To verify need You to a statement check could and that verify it the justifying (in other works for statement words, some ‘the prove the truth of it), you examples. difference between can You consecutive square numbers is odd’ by giving these − 121 = 23 and 49 − 36 = Give some more justify the examples statement, you to verify the statement. need to give reasons why it is true. by can justify explaining e dierenc ● Show that every even square number is followed by an number and vice versa, so the difference square numbers must always be an High Lift cross-section of aircraft number. pressure wing Low speed, increased 4 9 2 odd speed, reduced the about air ies pressure and b elow its wings, between and consecutive in it why odd above square g observin by ying. You To ies, an 13 it ● that examples: airplane 144 verify pressure how this gives it lift. Justication The word justify ‘justier’, standard The If meant most the evidence the only no such in the the new sale, the To humans negative the to court French verb proceedings’. prosecution must The prove the the are run is clinical evidence on that found found the defendant guilty. not trying to conditions, Before justify is If there guilty. research incurable to is continually effectively. they facts defendant medical needs collect these defendant as-yet more of that a new the trials to positive or to drug drug test produce is can safe the results treat go and drugs as well as effects. The not in treat this, and trials committee. will to do then then company side clinical can that companies conditions effective. trial submit explanation evidence, medicines curable All 12th-century case. crime, Pharmaceutical on the facts Justication on ‘to courtsis logical committed is from evidence prosecution presents or comes which in using be reasonably have to be approved researchers exposed be to must by justify unnecessary expected to improve a scientic that risk, the and patient and an ethical volunteers that the in new the drug care. 4 9 3 Well-rounded 13.1 ideas Global context: Personal and cultural expression Objectives ● Finding angles Inquiry and lengths using circle theorems questions ● What ● How are the circle theorems? F ● Proving ● Examining ‘If thetruth their results of using ... circle then ...’ theorems statements and testing do we justify mathematical C converses CIGOL conclusions? ● Is the opposite of a true statement D alwaysfalse? ● ATL Can aesthetics be calculated? Critical-thinking Draw reasonable conclusions and generalizations 13.1 13.2 E13.1 Statement of Inquiry: Logic our 4 9 4 can justify appreciation generalizations of the aesthetic. that increase G E O M E T R Y Y ou ● should name the ● These A case, pass of tangent Line the line a L is the the to: Draw a circle, then draw a a radius b a diameter c a chord d a segment e an f the center g the circumference basic and label: arc circle theorems theorems? tangent line same lines. touches the curve at the point of contact and does gradient (slope) as the curve at the point where the curve. tangent the the T R I G O N O M E T R Y curve. the the 1 circle illustrate the how circle tangent has touches intersects are all through tangent L What diagrams each not par ts know Discovering F In already A N D circle to a at only circle at one point point, P if L P. P ATL Exploration 1 Using a GDC 1 or dynamic geometry Q A software, construct a circle with line segment center connects O which passes through a second point, points, Add a third point Q, not on the circle. but a line segment joining O to P, a line P extends Draw two P. in both and directions. add the line PQ O Continued on next page 13.1 Well-rounded ideas 4 9 5 2 Move the Repeat and a point few nding Q freely times a new by until the line repositioning position for Q so PQ P is (and that a tangent hence PQ is a to the changing tangent to circle the the at P. circle) circle. Q P P Q O 3 Now use Describe your a is GDC anything the circle. the relationship P is a point circle, the a the tangent perpendicular dynamic notice your between of on or you Compare circumference If O to geometry about ndings a angle with tangent and software OPQ others. the to when Form radius at a a measure PQ is a ∠OPQ. tangent conjecture point P on to about the circle. circumference to the the circle radius at of P OP P O ATL Exploration 2 P 1 Using draw a a GDC circle or dynamic with Draw another of circle. center point, P, geometry O on and the software, diameter AB. circumference O the 2 Use 3 Move the the Draw software point circle. 4 Repeat 5 Compare P to circles your line segments measure around Describe with the the you dierent ndings with notice BP A B 13 Justication of about ∠APB diameters. others. ndings. 4 9 6 and ∠APB circumference anything of AP Form a conjecture based on your G E O M E T R Y A N D T R I G O N O M E T R Y ATL Exploration 1 Using draw a a chord GDC circle AB. 3 or with Draw circumference segments 2 Use the 3 Without dynamic AP center O another of the and software geometry software, P and point, circle. P, Draw on the the line O BP to measure ∠APB B A the moving circumference anything you 4 Now 5 Move point A B. 6 A of P A Compare B around your move (or the P around Describe ∠APB both). Describe circumference anything ndings point circle. about or Describe B, the notice reposition and or you with notice others. the of the about Form eect a of circle, this on without ∠APB moving ∠APB conjecture based on yourndings. A cyclic vertices quadrilateral all lie on the is a quadrilateral circumference of a B whose circle. C A D ATL Exploration 1 Using a points line 2 3 Use GDC P, Q, the Now or R segments 4 Tip dynamic and so on that software reposition S to any geometry the PQRS circumference. is measure or all software, of a cyclic ∠PQR the draw Join the a circle four and points mark with four Make straight quadrilateral. and points. points S are sure P, in the Q, R order, and so your quadrilateral does not ∠RSP. Describe anything cross you itself. notice about the quadrilateral 4 Compare relationship between ∠PQR and ∠RSP as the cyclic changes. your ndings with others. Form a conjecture based on yourndings. The the To major minor show point on arc arc the the is is the the long way around and short way around a direction you circumference can of include the circle. a circle, A minor arc third e.g. ADB major arc B D 13.1 Well-rounded ideas 4 97 ATL Exploration 1 Using a a circle on the GDC with 5 or dynamic software, O. Mark two circumference. Draw another the major AO and center geometry arc AB. Draw the line points A and point, segments P draw B P, on AP, BP, O BO B 2 Measure 3 Move ∠AOB points Describe ∠AOB A, and B and anything and 4 Repeat 5 Compare ∠APB the ∠APB P, you as keeping notice you exploration your A ndings vary with the a with P in about the the major positions circle of others. arc. relationship a of A, dierent Form a B between and P diameter. conjecture based on yourndings. ATL Exploration 6 Tip C 1 Using a a circle GDC with or circumference. and 2 CA. Also Draw ∠ABC Measure the tangent, 3 Move 4 Repeat 5 Compare your and the A, the line A, software, B and segments to the C AB, circle draw on B be BC, at a A and and the C. ndings and tangent. Describe with AB a with anything circle others. of a you notice. dierent Form a diameter. conjecture based on ndings. Activity Did you 2 6? to illustrate the nd it Below them. questions Five ve Read below to explain ways the the of ve the writing rules, rules you these look at discovered rules the and ve diagrams, in Explorations diagrams and then to answer diagrams. rules: i Thales’ ii Opposite iii Angles iv Alternate a dicult are point theorem: in An angles the same segment is in equal angle a cyclic the in a semicircle quadrilateral segment theorem: to inscribed subtended the angle angle are by between subtended by is a right angle. supplementary. equal a the chords chord chord are and in equal tangent the in size. at alternate segment. Continued 4 9 8 13 Justication software able to should tangent construct to a automatically . A between Y our O its ∠ACB. exploration your geometry points tangent angles AC B and the and acute points O draw Measure the dynamic center on next page circle G E O M E T R Y v The the angle angle subtended at subtended Five a the by by a chord circumference the same at the center (inscribed (central angle) in the angle) same is A N D T R I G O N O M E T R Y twice segment chord. diagrams: x + y = b 180° c x x y O x d e x x x O 2x Tip Make ● What do inscribed, these same terms mean?: segment, subtended, alternate segment. supplementary, Look them opposite up if you angle, need to. Match each rule to its you understand terms, can ● sure so all that understand Match You can each use Example rule these to ve the diagram. information ● these you one of results the to Explorations nd angles in 2 to in 6. geometric a given question. problems. 1 Find the value of your reasoning. angle t, and B justify 60° D O t 50° C ∠CDE = 60° because ∠CDE and E ∠CBE ‘Justify’ means ‘give clear reasons for your answers’. are angles ∠CED = in 90° the same because segment. the angle inscribed CD passes through O, so it is a diameter. in a semicircle ∠BED ∠t is a right = 90° − = 40° because = 180° = 80° − 50° 60° − because triangle angle. ∠CED = 90° 40° the sum to interior angles in a 180° 13.1 Well-rounded ideas 4 9 9 Example 2 A Calculate ∠BOD 128° D B O C ∠BCD = 180° − 128° Opposite angles quadrilateral ∠BOD = 52° = 2 = 104° × The 52° the Example Prove that are in a cyclic supplementary. central angle inscribed is twice angle. 3 ∠BOD = C 64° O D B ∠BCD ∠BOD = = 32° 64° Practice by the alternate because the segment central 32° theorem. angle is twice the inscribed angle. 1 Tip 1 Calculate the size a of the marked angles in each b diagram. Calculate c and nd e both mean that 41° you should show a O O relevant 27° c your working, 5 0 ° you to do not justify e f h 28° 130° n O m g j 36° 5 8 ° k 5 0 0 13 Justication but need all reasoning. d in f d b stages your G E O M E T R Y Problem 2 Find In the each A N D T R I G O N O M E T R Y solving size case, of the marked justify your angle in each diagram. answer. H D C E B K 40° c O O a 28° b A J F G I P A B U e 70° Q F O 70° C f 78° V X d T W 20° D R S E Justifying C ● In this How section Objective: iv. do you C. we will the justify use circle theorems mathematical direct (deductive) conclusions? proof to justify the circle theorems. Communicating communicate complete, coherent and concise mathematical lines of reasoning The following sure your two proofs proofs are Exploration 1 Copy and complete concise and the that proof they of the make cyclic quadrilateral theorem. Make sense. 7 complete this skeleton proof. Theorem Opposite angles in a cyclic quadrilateral are supplementary. Proof Consider a cyclic quadrilateral ABCD inscribed in a circle with centerO A B A diagram makes it easier for readers O understand your proof. D C Continued on next page 13.1 Well-rounded ideas 5 01 to OA = OB = Therefore OC = OD ΔOAB, because _______, ____________ _______, What and _______ Therefore _______ because ∠OAB are all ∠OAB = = _______ ∠OBA, _______, and type of triangle _______ _______ = = Use the ’triangle fact‘ from + ∠OBA 2(∠OAB + ____ + ____ + ∠OAD + + ⇒ + ____+ ____ The D the are proof is Bydrawing that the angles at A and + _______) _______) _______ Therefore 2 _______ 2(∠DAB and the line above. ____________ ⇒ B ΔOAB? _______, _______ + ____+ ____ = 360° ⇒ ⇒ is triangles. + C = = means ’implies‘ 360° 360° _______ are = Notice how ∠OAB + ∠OAD = ∠DAB 180° supplementary, and the angles at supplementary. incomplete suitable opposite as you diagrams angles are need and to consider modifying supplementary in two the other proof, cyclic cases. prove quadrilaterals where: a one b the edge of center the of Exploration Copy and quadrilateral the circle is not passes inside through the the center of the circle quadrilateral. 8 complete this skeleton proof of Thales’ theorem. Theorem Any angle inscribed in a semicircle is a right angle. Proof A O B C Consider point on ΔOAC a circle the and with center circumference ΔOCB Hence ∠OCA ∠ACB = = ∠OCA are _______ _______ + O of and where the AB is a diameter. Let C be any circle. triangles. ∠OCB = _______ ∠OCB Exterior ∠AOC = _______ + _______ and ∠BOC = _______ + interior Continued 5 0 2 13 Justication angle = sum of _______ on next page opposite angles. G E O M E T R Y ⇒ ∠AOC = 2∠OCB ⇒ ∠AOC + ∠BOC = 2(_______ ⇒ ∠AOC + ∠BOC = 2 ⇒ 2_______ ⇒ _______ = = and ∠BOC = T R I G O N O M E T R Y 2∠OCA + _______) _______ 180° ∠OCA + ∠OCB = ∠ACB 90° Exploration Copy and A N D 9 complete this skeleton proof. Theorem Angles in the same segment are equal. Proof A P R B Q Consider the points chord ∠PAQ + ∠PBQ because Hence through ∠PRQ + ∠PRQ ∠PAQ circle, = and P B and that Q. lie in Point the R same lies in segment the of opposite a circle divided by segment. _______ = _______ _____________________________________ Example A A = _______ 4 center circumference. O, has RST is points a S and straight T line on R its segment. S Prove that ∠SOT = 2 × ∠RSO 180° O T ∠OST = 180° − ∠OST = ∠OTS ∠SOT = 180° − ∠RSO (base (angles angles ∠OTS − ∠SOT = 180° − 2∠OST ⇒ ∠SOT = 180° − 2(180° ⇒ ∠SOT = 2 ∠RSO an ∠OST ⇒ × in on − a straight isosceles (angles in a line) triangle) triangle sum to 180°) ∠RSO) 180° 13.1 Well-rounded ideas 5 0 3 Practice 2 Problem 1 Points such A, that solving B and A, B C lie and C on all a circle fall with within center the same O semicircle. 1 Prove that ∠ABC = 180° − O ∠AOC 2 A C B 2 Points The Let P, X and tangents O be the Y to lie the center on the circle of at the circumference X and circle. Y meet Prove of at a P circle. Q. that O Y 1 ∠XPY = (180° − ∠XQY). 2 X 3 Points a B, tangent D and to the E lie on circle a at circle. B. DE ABC is is parallel to ABC E D Prove that ΔBDE is isosceles. O C B A 4 A, B, and C and when extended Prove D lie the line they that on circumference segments meet ΔACX the is at X, AB and outside similar to of DC the a D circle, are circle. ΔDBX A Tip C B Remember that two X triangles 5 A, B, C, D, E and F lie on the circumference of a if with AB = BC and DF perpendicular to their BE and CE meet DF at X, Y and Z respectively. that ∠EXY = B ∠EZY. ‘Bisect’ cut D The D The converse ● Is ● Can theorems the opposite aesthetics you have statements. For and diameter, be AC split is a into 5 0 4 ‘If then parts, of be proved example, two are same. Y Z Prove angles A E BE. the AE, similar F X circle, are the a of the true circle statement theorems always false? calculated? are points ∠ABC all A, is premise a of B right (the 13 Justication the and ‘if ’ form C lie angle’. part) ‘If on p, Y ou and then the can the q’, where p circumference see that conclusion the and of a q are circle statement (the ‘then’ can part). in means half to exactly. G E O M E T R Y ● If ABC ● If x ● If x is is a a triangle, whole then number ∠ABC which + ∠BCA ends in a + ∠CAB zero, then = 180° x is not A N D T R I G O N O M E T R Y Tip prime. 2 ● If x = + 4, 3 then = 7, x = then 2. x You = the 4. p then This Reect and discuss The the of the converse opposite These ‘If of a If ∠ABC ● If x is + not then …’ statement order. statements ● … So are the ∠BCA prime, the + statements takes its converse then x is = a two of converses ∠CAB also is q’ as p read write ‘If ⇒ q. as 2 ‘p Which can statement ‘If of above then four then whole q’ parts ‘If q is a and then previous ABC number is q’. true? constituent p the 180°, are implies places them in p’. statements. triangle. which ends in a zero. 2 ● If x = 2, then x ● If x = 4, then x + 4. 3 = 7. Reect and discuss ● Which of preceding ● If the original statement is true, ● If the original statement is false, You should working not with of theorem and circumference what the is be: of ‘If a converse a its once ∠ABC circle, is and means – 2 two points Draw a A and third then a and then then is then their a that ‘If also converse converses you an ‘If have … can to false? be be then true? true? also true or careful …’ is angle A, a then diameter’. it is B and right points It’s not a C lie angle’. A, little obvious on The B false when statement the does circumference converse and C harder lie to whether on see or of the the exactly not it is true. Tip geometry software to C draw C point are true. points certainly statements converse the proving is …’ the is and ∠ABC right is … means more: AC dynamic or This diameter, 1 GDC ‘If converse 10 a of statements Exploration Use list justication; that theorem AC would that 3 another. and mean Thales’ circle seen one proof necessarily Consider a the have independently of = A D, and the line segment Y our be a AD software able to should construct perpendicular to a B line 3 Draw a line perpendicular to AD through through a point. C. D Let point B be perpendicular You part a have of right stays 4 Use the point 5 the B. Explain a converse By same Trace Vary if intersection through created angle. the the set of of AD and the C of three Thales’ moving point points, A, theorem: D, you B and three should C that points see satisfy such that as the that B ‘if’ ∠ABC moves is ∠ABC size. facility the your of your position diagram of GDC B by supports or software moving the to track the position of D converse of Thales’ theorem. 13.1 Well-rounded ideas 5 0 5 Reect Is and Exploration suciently discuss 10 the a GDC other others, is that the tricky or four the – that dynamic same the you converse believe geometry theorems you size know as of the opposite angles this in one how a software also another. so tackle of Thales’ theorem? converse to be If true not, is it anyway? 11 circle provided that proof convincing Exploration Use a 4 hold. to use the Exploring cyclic to Some verify are software the that to converses produce converse quadrilateral the signicantly are of the easier an of than angle theorem supplementary is quite last! Summary Line a L is circle the at tangent point P L to ● if Thales’ theorem: inscribed in a An angle semicircle P L intersects at only one the circle point, is a right O ● Opposite cyclic A cyclic angle. P quadrilateral is B a angles in a quadrilateral x + y = 180° are supplementary. x quadrilateral whose vertices y all of lie a on the circumference circle. C A ● Angles in the same D segment subtended by x x equal The major arc is the long way around the a minor major arc arc is you the short way around. can circumference of the A circle include circle, a third e.g. To point to a size. on the ADB. Alternate The at a point P on segment angle theorem: between a chord its and circumference equal indicate ● tangent are circle; in the chords tangent at a point x is is equal to the angle P perpendicular to its subtended radius by the chord OP in the alternate segment. x 0 ● The angle subtended by x a chord twice at the the center angle at is the O circumference in the same subtended 2x by 5 0 6 13 Justication segment the same chord. G E O M E T R Y Mixed 1 Find A N D T R I G O N O M E T R Y practice the size of the marked angles. a b c If it d If a it is is a bird then polygon a has it has four wings. sides, then square. b 40° 2 e If c = f If a 9 then c = 81. O 42° 65° c right-angled triangle is drawn with a itsvertices on circlethen its ofthe 2 Find the Justify size your of the marked the circumference hypotenuse is a a diameter circle. B A angle. 4 answers. a of In the cyclic ABCD, b quadrilateral ∠DAB ≅ ∠ABC. a Prove that AD = BC 67° D O 132° B 5 A, B, C and D lie on a b circle DOB 3 For each statement, Determine which write down statements, the and center bisects O, and ∠ABC converse. O which Prove that ΔABC A of a their If a converses, = 7 then are 3a 2 true. = is isosceles. 19. C D b If b = a Review then in a b = 0. context Personal and cultural expression 1 A circular end the of it. auditorium When a auditorium, patron’s eld the of has patron a stage sits stage at across O, occupies the 88° Find the center of of the wall total projectors so vision. the length projected their are on of the when the positioned beams overlap by stage 20 cm. 17° Find eld the of amount vision of that the the O stage would occupy viewed from edge the P, at P when the very P 2 of Three auditorium. projectors, used to display images Reect and How you have wall of mounted each a on have one above The circle a circular the performance opposite beam width another at a wall. of The 17°, single space, diameter 6 statement of Give specic examples. are are placed Statement of Inquiry: P Logic has the projectors and point explored on inquiry? the discuss can justify generalizations that increase m. our appreciation of the aesthetic. 13.1 Well-rounded ideas 5 07 It 13.2 strikes a chord Global context: Personal and cultural expression Objectives ● Using circle Inquiry theorems to nd lengths of chords questions ● What ● How can you ● How can a is the intersecting chords theorem? F ● Finding lengths using the intersecting chord apply the theorem? theorem theorem have dierent CIGOL C cases? ● Can aesthetics be calculated? D ATL Critical-thinking Test generalizations and conclusions 13.1 13.2 E13.1 Statement of Inquiry: Logic can increase 5 0 8 justify our generalizations appreciation of the that aesthetic. G E O M E T R Y Y ou should already know how A N D T R I G O N O M E T R Y to: 2 ● solve quadratic equations 1 Solve the equation 2x x cm has 3 = 0 for x by factorizing. ● apply the circle theorems 2 A circle point the how where Intersecting ● What ● How is th an the 5 a tangent circumference. is far 13 is cm this tangent from If a the point center from touches at point the the a on of the point circle? chords intrsting you radius the tangent circle, F of on apply th hords thorm? thorm? ATL Exploration 1 Draw a irl dynami Draw 1 of radius gomtry four points 5 using a GDC A or softwar. A, B, C B and D on th O irumfrn Draw hav 2 Not in lin a Stat and hords a so that suital CD th will Find th valus Vary th position rul 5 Vrify of It that hang you hav Th rsult irl B, hav dout. gnral and D. radius of th points, modify your intrst. points and A, of lngths CX × B, C and D intrstion AX, BX, suh of CX AB and that and hords CD as AB X DX. DX Dsri anything you noti, and rul. of is known ass, holds tru th of as Dtrmin of mt point th disovrd numr not CD th th BX C D position points. discuss you thorms. any × th do and masur should on. th on You irl. as th whih you intersecting this is ontinu whthr it Dsri th to vary ontinus any chords rst. th to positions hold limitations to whn th rul osrvd. that you AB thorm C th and intrsting a this Lal AX of hav has th A, you Reect of suital you points to CD CD ondition softwar theorem. to and intrst. 4 Th and varying hords Us a AB AB By 3 suggst irl. similar diagram. diagram th sgmnts diagram that this of In hords sn. Do A hav th just 1 found Exploration thorm y think that provd you hav in proof th must dynami th just dmonstrating mathmatial you is don, that show Extndd it th gomtry you haptr hav works in all rsult to approah on justid th tru dos th situations yond this? 13.2 It strikes a chord 5 0 9 Theorem: If A, irumfrn hord AX × CD BX at = a B, of C a point CX × and irl X D ar suh points that intrior to on AB th C th mts irl A th thn X B DX D Example In th 1 irl shown hr, hords AB and A C x CD mt at P. Find th valu of 3 x B P 4 12 D Make AP × BP = CP × sure that you correctly DP identify the sides involved. ⇒ Example In this 2 irl, hords PR and QS mt at T. Q Find th valu of x and hn nd th possil x valus of th lngths of PT, RT and 1 QT P x x + 1 R T 6 S PT × RT = QT × ST x × (x + 1) = (x − 1) × 6 Substitute in the known values. 2 x + x = 6x 6 2 x − 5x + 6 = 0 (x − So PT 2) (x − 3) = 0 x = = 2 2 or or 51 0 x 3, = Factorize. 3. RT There = 3 or 4 and QT = 13 Justication 1 or 2 are two possible values of x G E O M E T R Y Practice 1 Find th A N D T R I G O N O M E T R Y 1 valu of x in ah diagram. Hn nd th missing b a lngths. c 5 x 4 9 x + 1 4 10 3 8 2x x x e d 1 f 4 x x x 3 6 x x − 1 3 10 x + x 3 x x Chords C ● How that an a intersect thorm 2 1 hav outside dirnt the circle ass? ATL Exploration Not 2 that ontinus 1 Draw a irl using a GDC or softwar. dirtions, four points A, B, C and D on th Draw lins AB Draw point X, of th and line segment B whih X irumfrn oth unlik A a Draw line in dynami C gomtry a irl. stops at its ndpoints. CD. whr AB and CD and intrst. D You 2 should Mov CD is th mt th hav points diagram so xtrior sond a as that to lins th of similar AB irl. th to this. and A This B intrsting X C hords Using thorm. th softwar, masur th lngths D AX, BX, CX and rlationship AX th and lins Can you AB DX. × possil to BX CD dsri say Vrify = CX that × intrst any that th DX onditions AX × still xtrior BX = holds to undr CX × whn th irl. whih it would not DX ? 13.2 It strikes a chord 51 1 Th intrsting point. th You hav hords now thorm sn that rfrrd th to thorm hords is that idntial intrst if point P at is an intrior xtrior to irl. Example Points J, K, 3 L and M li on th irumfrn J of a LM irl. Th intrst at lins P. that Find pass th through valu of JK and 10 K x 2 P 3 x M L JP × KP = LP × MP ⇒ Substitute in the known values. ⇒ ⇒ ⇒ Practice 1 Us th Hn 2 intrsting nd th hords missing thorm lngths a in to th nd th valu of x in ah diagram. diagrams. b c x x + 1 1 2x x 6x x 9 1 2 1 x x D When ● Can a chord asthtis 3 2 becomes a tangent alulatd? ATL A Exploration 3 You may nd to B mov 1 Rall th diagram from Exploration sur stp 2 whr th lins AB and CD xtrnally at X C D Continued 512 13 Justication to that mak Xrmains X on mt A 2 on next page th pag. G E O M E T R Y 2 Us th softwar onrm that AX to × masur BX = CX th × lngths of AX, BX, CX, and DX A N D T R I G O N O M E T R Y and DX. A B X C D 3 Mov th th othr and hk 4 What 5 Rpat as 6 do stps In 3 your th it gts rmain aout 4 a th fw losr to stationary. intrsting and A. and th a 3, th hords two mor th mak your what point onjtur intrsting Us Tst discuss Exploration Mak ● that osrvations, approahd ● so noti approahs Reect ● that you B points A. You thorm lngths tims, should R-masur AX still and allowing four sur that lngths applis. BX B mak th as and B A approahs to gt as A? los possil. From B point thr for softwar to onjtur a aout th limiting as as 2 happnd A? hord a onjtur. What to th othr lin lin tangent-chord AX dos theorem as this that th point B rsml? is th limiting as of thorm. onstrut a tangnt to a irl and onrm that your Just onjtur is as in tru. Explorations and 2, usd The If tangent-chord TX PQX is a tangnt mts th to theorem: a irl irl at P T at and T Q, and fully 2 PX × QX = and tst onjtur. thn to a To justify th onjturs TX 1 hav softwar form X you that Q you hav proof If P is you hav writtn using mad, similar might prov sor playr running down th sidlin tak a shot with th st han of you al th to thorms wants in to alrady proofs triangls, A a ndd. this stion for soring G yourslf. a goal. It turns out that th st han for To gt a O startd, sussful shot happns whn th playr irl that is at th an point th of goal tangny posts and of is th tangnt to th passs through s if you A xplain why L triangls PTX TQX similar. and sidlin. 13.2 It strikes a chord ar 513 Summary ● Th If intrsting A, B, C and hords D ar ● thorm: points on Th If th tangnt-hord TX lis tangnt thorm: to a irl at T and PQX mts 2 irumfrn th hord thn AX CD × of at BX a a = irl point CX × suh X that intrior AB to th mts th irl at P and Q, thn PX × QX = TX irl DX T X C A A B B X Q X C D D P Mixed practice 1 has A irl points irumfrn. A, B, Chords C AB and D and on CD its 3 hav lngth Find x, y th and valus of z 5 x 11 and irl a 7 at rsptivly, point Sketch C,D th and X and mt intrior to th A, B, X irl on and th indiat points 5 6 y skth. z b Givn that AX, BX, CX and DX ar intgrs, 4 nd th possil valus that thy an In th A tak. diagram, 2 Find th valu of th unknown(s) in ah BC diagram. is a hord x 3 D and a mts b x O 5 a 7 diamtr 8 AB at B. AO = BO y 3 40 x + = 3 5 8 and BC = C 8. B Find x and y R x 5 15 Find th valus of x c x d and 2 y Q x 5 + 1 x 4 y y 14 8 x 5.5 P 2 y 4 T 2y 10 x 1 6 x e x f In this a show 3x = diagram: 2x 3 that 4y 11 4 x 3x 16 b hn valus nd of x th and y 3x 2 4 3y 6 16 51 4 13 Justication 2 G E O M E T R Y Objective: ii. select D. Applying appropriate mathmatis mathematical in ral-lif strategies A N D T R I G O N O M E T R Y ontxts when solving authentic real-life situations For each of determine the Review A version in Personal 1 questions which fragmnt the consider the intersecting geometry chords of the theorem real-life you of a cultural owl, dats Arhaologists owl th A situation to aring an anint from th 7th ntury liv th original 2 bce. owl Hug in was and AB midpoint B ar is hosn masurd of AB, and on to MC th is dg 5 m. of M th hallngs is spially prpndiular whr C lis on th irumfrn of th is masurd to hav East. to nd out hundrds has as n som n disovrd Arhaologists to of mor of aout mtrs thm ar ths aross, masur in hav thm Jordan n irls. on of th auratly, inomplt. to points, A and B ar markd on th irl and owl. th MC irls Middl attmpting Two AB ston th Masuring and and use. expression irular. Points need context and insription, below, of distan twn thm is masurd. Th mid- 0.25 m. point of AB is point to th narst Survyors distan a Use found from this sond mak and a that th of of From straight masur a distan on AB th was to from irl 114 was 9 is m this masurd. and th m. calculate th irl. arhaologists point lin th th midpoint th group thniqu. and point information diamtr A found outsid whih distan is to a us th a irl tangnt th dirnt point to of thy th irl ontat. C Thn A thy original masur point to th th shortst distan from th irl. M B a Sketch th sgmnts omplt AB and owl, inluding th Th b lin distans Calculate ar th 150 and diamtr masurmnts MC m and 52 m from thn rsptivly. ths compare th tworsults. b Show that th c ntr Use th th th of sgmnt owl intrsting diamtr Reect and How you hav lin th of th MC whn hords passs through xtndd. thorm to nd owl. discuss xplord th statmnt of inquiry? Giv spi xampls. Statement of Inquiry: Logi an of asthti. th justify gnralizations that inras our appriation 13.2 It strikes a chord 51 5 14 Models Depictions of real-life events using expressions, equations or graphs Modelling The length The area of a a problem rectangular garden is twice as long as its width. 2 Find the Drawing a of the garden dimensions a diagram of can is 72 the help m . garden. you write an equation to represent situation. 2x x ● For to the nd x, Translating equation adapt ● a rectangular a and word creates model Adapt then to your rectangular a garden, nd the problem model solve garden eld the similar model and length into of whose write a 51 6 and has an area problem. equation width. expression Sometimes you or can problems. to nd length of and an mathematical is the 7500 dimensions three 2 width, solve m times as of a long as its Estimating Using a model reasonable The ● human you calculate body is about water. Modelling calculate volume ● help estimates. average 60% can How an of to body estimate water could model more your you make in as a for your improve your cylinder, the body. your estimate accurate? Should you take an umbrella? account of the atmosphere, thermodynamics and the uncertainty formation equations in a of chaotic of the motion and system. 51 7 The 14.1 power Global context: Objectives ● Recognizing of exponentials Orientation Inquiry exponential functions in space and time questions ● What ● How are exponential functions? F ● Using exponential functions to model real-life problems ● Identifying and using translations, do you transform exponential MROF C reections functions? and dilations with exponential functions ● How of do you recognize exponential transformations functions? ● Do exponential ● Do patterns models have limitations? D ATL lead to accurate predictions? Critical-thinking Draw reasonable conclusions and generalizations 10.1 Statement of Inquiry: Relationships predict model duration, patterns frequency of and change that can help clarify and variability. 14.1 51 8 A LG E B R A Y ou ● should evaluate already expressions know how with 1 to: Write down the 0 exponents ● identify a and reections apply and translations, dilations 2 value of : 4 2 b Here is 1 2 the c graph to of 2 4 y d = 3 f(x). y functions 6 4 2 x 4 2 2 4 2 4 Sketch a y c e Exponential F ● What are Exploration 1 A wealthy Option of 1: b y = f(x −f(x) exponential oers one-time d y = f( money to a y 2f(x) f y = f(2x) charity donation in Option day four 2: Now a nd Copy the and any total calculations, amount complete Day Amount (cents) Amount as the donated b 3 Write Use your days 4 1 Graph to a of day each 3, day, option Option of on and for gives one day so 20 the cent 2, on, days. most money. 2. 1 2 3 4 5 1 2 4 8 16 a GDC your under on cents 2 2 function 20. which donation two cents ways: table: 2 power predict two A 1, doubling 2 2) x) functions? on doing 3 functions $5000. Without + of : y = = f(x) graph 1 donor A = the or Find a for the amount spreadsheet the function total from in to US step on day work dollars 2b for 1 x out for ≤ x the all ≤ amounts 20 for days. 20. ATL Explain which option gives the most money. 14.1 The power of exponentials 51 9 x In a function increase, the y y = b , where values Exploration b is a increase positive very integer greater than 1, as the x values rapidly. 2 x 1.1 1 Graph a the slider the function for slider the to y = b and parameter explore b. what insert Move y happens 6 x to the than graph for values of b greater y = b 5 1. 4 a State of y what as b happens to the value 3 increases. 2 b Determine remains if the the y-intercept same for all b 3.0 0.0 1 10.0 values 0 of c b. Determine an Explain of e if the x-intercept, function d 3 Explain. x get will Suggest ever what less is, be equal an to x 1 1 2 3 4 has whether happens and why function that 2 to the the 0. value of y for x < 0, as the values less. exponential function with b > 1 is called an ATL exponential growth function. 1.1 2 Now redene the slider so that 0 < b < 1. y 6 Answer parts a, b and c in step 1 for x y = b 5 this function. 4 a Explain what value y happens to the 3 of for x > 0, as the values b of x get larger and 0.3 larger. 0.0 1.0 1 b Suggest why function an with 0 exponential < b < 1 is called 3 exponential Explain what decay happens x 0 3 an 2 1 1 2 3 4 function. to the graph if b < 0, and justify your answer. x An exponential The function independent Exploration 1 By choosing a is variable of x the is the form f (x) = a × b , where a ≠ 0, b > 0, b ≠ 1. exponent. 3 xed value for b where b > 1, graph the function x y = a × b and y-intercept 2 Repeat 3 Explain step 1, how exponential 5 20 insert a slider for the parameter a. Describe how the changes. but the this value time of function. 14 Models a choose is a related xed to value the of b such y-intercept for that any 0 < b < 1. A LG E B R A x The exponential any x-intercepts. function y = b does not have y 4 x y For b > 1, as x gets less and less, b 2 function approaches 0, but = b the never equals 3.0 0. 0.0 10.0 x 0 4 For 0 < b < 1, as x gets larger and 2 2 4 larger, y the function approaches 0, but never equals 0. 4 x x For any value of b > 0 the function y = y = b b b has a horizontal asymptote at y = 0. 0.3 2 0.0 1.0 x 0 4 A horizontal gets larger Reect asymptote and is the line that the graph of 2 f (x) 2 approaches 4 as x larger. and discuss 1 x ● Here is the Deduce graph the of value exponential of b from the function y = b y graph. (1, 4) Check the of your answer exponential b you chose. by graphing function Explain with how the you value found b ( ● Identify the value of b from the 1, 0.25) second (0, 1) 0 x x graph of y = b . Explain how you found b y ● Given the standard form of the exponential x function the is value y of = a a is × b 1. , for these Explain two how Tip graphs you ( could 1, 4) Look identify the value of a from a graph y = a × b you where a ≠ at anygraphs of x drew in (0, 1) 1. Practice 1. (1, 0.25) x 0 Population growth, radioactive substances, can all be modelled bacterial and with and viral nances growth, such exponential as spread interest of and epidemics, decay credit payments card of functions. 14.1 The power of exponentials 5 21 Example There are 128 eliminated a Write b players after a round 1 each table of in a tennis tournament. Half of the players are round. values, and a function for the number of players after x Determine the number of rounds needed to declare a winner. a Round number Number (x) at end of of 0 players round (y) 128 1 2 3 Look for a pattern 4 in the y values. 5 6 7 y = 128 × 7 rounds After 7 rounds only one b are needed. player, the winner, is left. 1 In Example 1, a = 128 (the initial number of tennis players) and b = variable x 2 (the the factor round by which number, the and number y of players represents the reduces). number of The players left after represents round x In the standard form of the exponential function ● the parameter a represents the initial ● the parameter b represents the growth ● x is the independent ● y is the dependent 5 2 2 variable variable 14 Models (for (for y = a × b : amount or reduction example: example: (decay) time) population) factor x A LG E B R A Practice 1 One 2 1 bacterium a Write down b Use c Graph your the ii when The a divides function function your i cell formula number there half-life to of of for produce the to be the of cells cells number every after of x cells minute. minutes. after 15 minutes. determine: after 1 carbon-11 two number calculate cells will to half an million is 20 hour cells (after how many minutes). minutes. The a A sample of carbon-11 has 10 000 nuclei. Make a table of values for a 20-minute intervals, and write down a function for the number of half-life radioactive nuclei material after x number of 20 minute Find the number of nuclei is the intervals. time b of ve after 3 taken number hours. of for the nuclei halve. c Determine less than Problem 3 Drug dose of trials body the Determine By the it takes for original show reduces medicine how long Exploration 1 long of the number of nuclei to reduce to number. solving testing person’s how 10% choosing a that by the one when after a amount quarter there dose is of of a every less 400 hour. than mg pain-relieving it It is 200 mg will be safe in to the safe medicine take in a another body. to take another dose. 4 xed value for b such that b > 1, graph the function x y = a × b and insert a horizontal asymptote asymptote of slider for changes, the parameter and write an a. Describe equation for how the the horizontal x 2 Do the that 0 same < b < any as 1. exponential in step Write 1, an but equation this equation time for y a × b select a xed the = when horizontal b > value 1. of b such asymptote of any x exponential The parameter fraction. So if an To b, the increase initial End equation of = growth an amount day y 1 × b , factor, initial y a may amount increases End for of by day 0 < be by b a < percentage 10%, 10% each 2 1. End you day , of 2 1.1y To So decrease if an an initial End of 1.1 initial amount amount day 1 y y by of 5%, by day 0.95 day 1.1 2 0.95y then 3 by you of 1 an + y 2 you 5% End End of day 1.1 by 1 then day x 3 0.05 you = y 0.95. have: End of day 3 0.95 or 1.1. have: y day, of = x multiply each integer 0.1 3 decreases End instead multiply y x x 0.95 y 14.1 The power of exponentials 5 23 to x Exponential decimal growth form (the is modelled percentage by y = a(1 expressed + as r) a where r is the growth rate in decimal). x Exponential decimal modelled by y = a(1 r) where r is the decay rate in 2 population population has a Determine b Write c Use a in a the to the factor b = estimated year factor model to year was each growth function in Growth town increased function your people) a is form. Example The decay b by of future estimate to be 38 000 the population population the in approximately 2015. Since then the 2.4%. in the town. growth. population (to the nearest hundred 2030. 1 + r = 1 + 0.024 = 1.024 Change 2.4% to a decimal and add 1. x b y = 38 000 years, c x = × 1.024 y = and 2030 , total 2015 = where x = number population after x of x years. a = initial population, y = a(1 + r) 15 15 y y = 38 000 × Example Sarah 54 234.4 Find x and substitute into the model. 3 bought a approximately a Find b Write c Use the a = 1.024 54 200 ≈ the a for $15 000. each depreciation function your to function nearest Decay car 15% (decay) model to Its value depreciates (loses value) by year. factor. the future estimate the value value of of the car. Sarah’s car after three years, to dollar. factor b = 1 r = 1 0.15 = 0.85 Change 15% to a decimal and subtract from 1. x b y = 15 000 and y = × 0.85 value of , where the car x = after number x of years, Dene years. 3 c y y = ≈ 15 000 $9212 Practice 1 For each ii the a y × in 0.85 = three 9211.88 years. 2 exponential growth/decay function, rate r, and identify iii the i the initial growth/decay value factor b, a x x = 2 x 1.43 b y = 3 × 0.62 y c = 4 × ( x d ) y = 0.8 × 3 2 A jeweler estimates a Determine b Write £300 c Use a in the growth function to value factor model of the of gold the is value future increasing of value by 12% per function to estimate 14 Models the value of year. gold. of a gold bracelet valued 2015. your 5 24 the that the bracelet in 2030. at 1.2 the variables x and y A LG E B R A 3 An electrical decreasing a Write b Use sell 4 In a there were of the cell year. that In model to the 2010 future estimate 3014 number they of sold DVD the initial The population registered phone number The a to function number Estimate 5 per DVD 470 players DVD sold is players. sales. number of DVD players the store will 2018. 2015, The calculates 22% function your in store by of population grows users cell of at an a is phone ant rate cell users colony of phone estimated 12% in in a increase small town. by 42% approximately 600. per year. 2025. was per users to week. Find: i the ii a iii the growth factor of the population of ants In function to model the population growth of the ants y approximate number of ants in the colony after 5b, on 15 weeks and the = b A a b Graph your population Write after 3 ii after 10 the your to 9 An less the it in and graph decreases use to it determine to reduce invest $5000 annually. to estimate by 9% calculate how to in a long less it than long-term Determine estimate decreasing take a how there rate population destroys for million that at 10% the of to how many weeks the ant every the year. number of insects left would half its take for present size. money many fund years it oering will take 4% for interest this be antibiotic How do you transform How do you recognize A. are 80 3.5% wolves per year. in a forest Estimate and how that the long it will halved. to present reduce in 50 one hour. million Determine bacteria how down to bacteria. ● Knowing appropriate of bacteria ● unfamiliar to size. Transformations Objective: select 1 the insects formula present would than C i. is antibiotic long x double. population for read of solving Conservationists take and value years. parents amount 10 000 a Use double population compounded 8 of to formula insect Sahil’s the years Problem 7 function. takes down i Use 1200, point where weeks. population 6 the graph after o 30 nd and of exponential exponential functions functions? transformations of exponential functions? understanding mathematics when solving problems in both familiar and situations In Exploration 5, use the rules f or transf ormations of graphs to justif y your conjectures. 14.1 The power of exponentials 5 25 Exploration 5 x 1 Graph the y = 3 and symmetr y on between the the two same set g raphs. of axes. Make Describe and justify a and justify conjecture x about the symmetr y of all x 2 Graph y = of g raphs of the for m y = b and x 3 symmetr y pairs and y = between −3 the on two the same graphs. axes. Make Describe and and justify a justify the conjecture x the 3 symmetr y Graph such the the that all pairs functions a value of > of 0. a of graphs below Describe varies, and what and state of the insert a type y slider happens the form to b for the of = about x and the shape y = −b parameter of the transformation a, graph as this represents. x a y = a × b x , for b = 2 b y = a × b , for b = 0.5 x 4 Graph By the function changing the y = value x function y = 2 + 2 of k, k, and state y = 2 function y + = k. Describe Graph By the function changing the y = value x function y = 2 for the y , of = 2 function y ab + Explain how takes k. the the transformation to from any k. h, and state insert the a slider for the transformation parameter that takes h. the h) . = Describe ab the (x to y = transformation transform the from any h) Tip ab x 6 parameter that h) 2 (x to to x exponential slider x ab (x 5 a transformation x to x exponential insert the function y = (x ab to y = − h) ab + You k may better the is Transformations of exponential functions y by Reection: For the exponential function f (x) = a × b looking : the graph of y = −f (x) is a reection of the graph of y = f (x) in the x-axis. ● the graph of y = f ( is a reection of the graph of y = f (x) in the y-axis. the right. x Translation: ● ● ● y = f (x For h) the exponential translates y = f function (x) by h f (x) units = in a the When h > 0, the graph moves in the positive When h < 0, the graph moves in the negative (x) + k y = f translates y = f (x) by k units in k > 0, the graph moves in the positive When k < 0, the graph moves in the negative = k units f (x h) in + the k translates y = f (x) by h b : x-direction. x-direction, the left. up. y-direction, in to y-direction. y-direction, units to x-direction, the When y × the down. x-direction and y-direction. Continued 5 2 6 14 Models − on next page y what 2 = at h) 2 (x ● x) = of a of transformation (x x get idea 2 − h) instead A LG E B R A x Dilation: ● y = af ● y = f For (x) the is (ax) a is a exponential vertical function dilation horizontal of dilation f f (x) (x), of f = a scale (x), × b : factor scale a, parallel factor , parallel af (x) a > y af(x) 0 < a < dilation f(x) horizontal f(x) dilation af(x) x 0 Example x-axis. x y vertical the 0 x y 1 to y-axis. f(ax) f(x) 0 vertical the f (ax) y 1 to f(x) f(ax) 0 x horizontal dilation dilation 4 x Start with the a In words, b Write c Without the a i the describe (x) the using a factor 0.5, functions 2, as program on the 0.5f (x) parallel = factor 2 transformation graphing transformation scale = function transformation scale The f transformed transformed The ii function to is a is parallel or = (x), 0.5f GDC, set vertical of and (x), i c i g (x) = 0.5 Graph of × (0.5x). and sketch dilation horizontal the ii both h (x) the = f (0.5x) function and of the graph of f (x), dilation of the graph of f (x), x-axis. 0.5x 2 f (x) f axes. x b ii y-axis. a to 0.5f g (x) same the f (0.5x) i i → Graph of g(x) ii h (x) = 2 ii Graph of (0, 1) → (0, 0.5) (0, 1) → (1, 2) → (1, 1) (1, 2) → (2, 4) → (2, 2) (2, 4) → f (x) → (0, 1) (4, 4) Graph of h(x) y y x f(x) = 2 5 5 x f(x) = 0.5x 2 h(x) = 2 4 4 3 3 2 2 1 x 0.5 g(x) = 0.5 × 2 0 0 3 2 1 1 2 3 4 x 3 2 1 1 2 3 4 x 14.1 The power of exponentials 5 27 Example Given the 5 functions a Describe b Write c Sketch a i g i is the g, a h in same horizontal ii h b i g (x) c i Graph (0, ii the negative is transformations and on : a x 1) f (x of set of of g, and ii h of 1, axes translation i f of and g, f 4 by and ii units + dilation of f, scale factor f and in 4) f (x) → Graph of g(x) 0.5, f. h the parallel the h (x) ii Graph of ( 2, 4) → ( 2, 2) ( 1, 2) → ( 1, 1) (0, 1) → (0, → = to ii → 2) function f → ( the direction. vertical = terms i 0.5f (x) f (x) → = ( 2 x+4 x = ( 2 ) 5 4 2 3 3 1 ( h(x) 1 f(x) 4 = of y y ) 5 g(x) Graph 0.5) x 1 f(x) y-axis. ) 2 2 x 1 h(x) = 0.5 1 4 3 Practice 2 1 2 ) 1 x 0 0 5 ( 1 2 3 5 x 4 4 3 2 1 1 2 3 4 3 x 1 You are given i Describe ii Write iii Sketch a f (x e 3 + f 2f 5 2 8 (x) (x) = function f and f f (x) (2x) solving j 3 below function b 1) f transformation the 2) (x function transformed both Problem i each the + the f ( 14 Models 2x) as in g(x) words. = ___. transformed c g f function (x) 2f − (x) 2 on the same d f ( x) h f (0.5x) set of axes. A LG E B R A 2 For each pair i Describe ii Write iii Sketch g of the in functions and g: transformation(s) terms both f of of function f to function g f functions on the same set of axes. x x a f (x ) = 1.5 1 x , g (x ) f b = −1.5 (x ) = x ( , ) g (x ) = 2 2 x c f (x ) = 3 e f (x ) = x +2 , g (x ) x = 3 − 3 d f (x ) 2 x = 0.5 , g (x ) = 0.5 g (x ) = 3 × x x 2 g (x ) = x 1 0.5 x , 2 f f (x ) = ( 1 , ) ( ) 3 Problem solving x 2 x 1 g f (x ) = ( 1 , ) g (x ) = ( ) 2 3 On the same 2 set of transformations. axes, Label x f (x ) = sketch each the graph graph and 2 x 2 ; 3 f (x ) = of any the 1 0.5 x 2 ; f 1 (x ) = function intercepts −2 × 2 ; f 2 (x ) f and with its the three axes. 2x = × 2 3 2 Modelling D with ● Do exponential ● Do patterns Exploration exponential models lead to have accurate functions limitations? predictions? 6 Bank In this rate exploration of 100%, you when will the investigate interest is how much compounded $1 at can grow dierent at an interest accounts usually intervals. pay compound per 1 Find the amount $1 is worth at the end of one year at 100% interest. 2 Find the amount $1 is worth at the end of one year at 100% interest means is interest annum, the which interest calculated and x compounded half-yearly. investment $1, is the In the growth function rate is = y = a(1 50% = + r) 0.5, , the and x initial = 2, as added interest 2 is 3 now Find compounded the amount two $1 is times worth per at year. the Therefore, end of one y year = (1 at + 0.5) 100% once a to the account year. 2 or y = 1.5 interest 4 compounded quarterly (every 3 months). In this case, y = (1 + 0.25) or 4 y 4 = Write of 5 $1 Use the 6 1.25 down at 100% your end an exponential interest function of one to year compounded nd at function the 100% interest monthly b weekly d hourly e each $1 your function. investment number of can times at in 100% times one if your it is per if interest. if it is is Justify of $1 is worth at compounded: f there investment year. c year the investment minute Determine grow x amount a Graph representing a limit daily each to the compounded your second. amount an the innite answer. 14.1 The power of exponentials 5 2 9 The two limit to decimal just π, like Leonhard Y ou and have Is and What that model model Sketch a the number non-repeating model the who for in e, one which number. rst growth appropriate for grow all It year is is of will graph a discovered of of population that are bacteria limit period ● What of growth this more environmental Sketch a humans Is your Why, ● over a human why Research the What graph or after it. of people, population bacteria, growth? growth necessary population? growth? accurately The of growth the bacteria over rate population accelerates reects a T ime long time. population? ● of number ‘e’ 0 population to 2 factors a $2.72, special populations phases is called one. growth factors could mathematician environmental sustain $1 actually discuss this the noitalupoP to a is innite problems like What It the such exponential look an that ezis ● is Euler, Reect can amount places. and seen insects. An the the growth that long more are necessary factors accurately period growth of graph to sustain limit reects growth human of a human population population growth growth? of time. dierent from your bacteria more accurately growth graph? not? types of factors environmental of human functions used populations to over an extended model period of and predict time. Summary x An exponential function is of the form The exponential function y = b does not x f (x) = The a × b , where independent a ≠ 0, b variable > x 0, is b ≠ the 1. have exponent. For any b > x-intercepts. 1, as approaches In the standard form of the exponential x 0, gets but less and never less, equals the function 0. function x y = a × b : For 0 < b function ● the parameter a represents the initial ● the parameter b represents the growth < 1, as x gets approaches larger 0, but and never larger, equals the 0. amount x For any value horizontal reduction ● ● x is the (decay) is the time independent dependent variable variable x) 53 0 b > 0 the function y = b asymptote at y = has a 0. factor. (e.g. time) A of y of or 14 Models (e.g. amount at horizontal f (x) asymptote approaches as x is the gets line larger that and the graph larger. A LG E B R A x Exponential where r is growth the percentage is growth expressed modeled by y rate in as decimal). a = decimal a(1 + form When r) h < 0, x-direction, (the the to graph the moves in the negative left. Exponential ● y = f (x) + k translates y = f (x) by moving it k x decay is modeled by y = a(1 r) where r is the units decay rate in decimal in of y-direction. form. When Transformations the exponential k > 0, the graph moves in the positive functions y-direction, up. x Reection: For the exponential function f (x) = a × b : When The y = graph f (x) in of y the = −f (x) is a reection of the graph of y = graph f (x) in of y the = f ( x) is a reection of the graph y = f the of = a × b y = f moves in the negative (x h) + k translates and k y units = f in (x) the by h units For the exponential For the exponential function f (x) = a translates y = f (x) by moving it = af (x) is a vertical dilation of f (x), scale factor to the y-axis. h y the = f (ax) is a horizontal dilation of f (x), scale x-direction. 1 factor , parallel to the x-axis. a When h > 0, x-direction, the to graph the moves in the positive right. af (x) a > f (ax) y 1 y af(x) f(x) 0 vertical 0 < a < 1 × b function y h) in in y-direction. : (x units graph x parallel ● the down. y-axis. x f (x) 0, x-direction Dilation: Translation: < x-axis. ● The k y-direction, y x dilation f(x) vertical y x 0 dilation f(x) 0 horizontal af(x) f(ax) x dilation f(x) f(ax) 0 horizontal x dilation 14.1 The power of exponentials 5 31 a, : Mixed 1 Xixi It practice bought a depreciates a Write for b down this Write car ve years ago approximately the for 15% depreciation 6 $18 000. every year. (decay) factor Gina invests 1.4% interest a State the b Write down down a function of the car to model over a savings growth factor account that pays annually. on this investment. of the the value of her car her a function to model the growth savings. time. c Find in compounded problem. depreciation c $400 now, to the nearest Determine how her to savings many years it will take for double. $100. 7 Write these transformations in terms of the x function Problem 2 A strain every 5 of the 3 end The bacteria one isotope At doubling midday the radium-226 nuclei. in there number a left are The after 1600 has years. Determine 150 pesticide of is: of reected b translated bacteria at c reected a A half-life in its and the y-axis d dilated by scale factor 3 parallel to the x-axis e dilated by scale factor 4 parallel to the y-axis. 3 units to the left and 4 units in the x-axis sample how many has nuclei will solving years. DDT is banned long-lasting animals. in most On the same toxic The eects half-life of set of axes, sketch contains of years. A sample graph f and DDT graph its and three any transformations. intercepts area of with the DDT. Determine (x) = DDT in the soil after 70 Label the axes. 2x 4 f (x) = 4 1 2 x 0.5x amount f (x) = −2 × 4 f (x ) = × 4 3 2 of the is soil 1 g of on x 15 the countries f approximately 100 down of each humans f a function because when 20 8 4 2 laboratory Problem be = hour. approximately 10 000 is Determine of (x) solving minutes. bacteria. f 2 years. x 9 5 The population of a town in 2010 was a Rewrite was at an estimated annual population rate size that of in its population 2.68%. the year will Determine 2025, to function f (x) = 9 with a base how you of 38 720. 3 It the the instead of 9. Then describe can grow graph this function in form the using the base of 3, ax the y = 3 nearest x b 100 Rewrite the function f (x) = 9 with a base of 81. people. Then describe how you can graph this ax function 532 14 Models using 81 as a base, in the form y = 81 A LG E B R A Objective: iii. In apply this fossils D. the Applying selected Review using in Review in mathematical context carbon mathematics you will in real-life strategies apply contexts successfully exponential functions to to reach a determine solution the age of dating. context Write Orientation in space and an exponential function relating time , N x, and N 0 Ötzi was German an found on tourists, elevation of 3210 Austrian–Italian clothing Simons and 19 were the and meters border. tools thought September Helmut 1991 Erika (10 530 Because so man well had by two Simon ft) the on at the University of you use your solve function the from following the Problem solving Innsbruck When it dies, an organism contains carbon dating to estimate died about 5300 years ago, nuclei 14 C. Calculate the number of C nuclei in the that organism Ötzi 30 000 in 14 used to recently. of Austria 1 problems. body, 2 Scientists can help the preserved, died You at making after 11 400 years. him 14 the oldest, best preserved mummy in the 3 world. The amount 0.25 times Calculate Carbon dating of fossils is based upon the decay of the the C in a amount fossil when approximate is calculated the age to organism of the be died. fossil. of 14 C, a radioactive isotope of carbon with a relatively 4 A fossil bone is approximately 16 500 years old. 14 long half-life of about 5700 years. Estimate the fraction of C still in the All living organisms get fossil. 14 14 C from the 5 atmosphere. Only 6% of the original amount of C remains 14 When an which begins organism to dies, decay it stops absorbing exponentially. in C, Carbon a ago dating fossil it bone. Estimate how many years died. 14 compares the amount of C in fossil remains with 14 6 the amount in the atmosphere, to work out Calculate in much has decayed, and therefore how long ago died. 1 = approximate percentage a fossil bone sample after 35 000 Analysis on an archeological animal site bone reveals fossil that 14 Let N the initial amount of C at the of C left years. the 7 organism the how the at an bone has lost 14 time between 90% and 95% of its C. Determine an 0 of death. approximate inter val for the possible ages of the bone. Let x = the half-life is number 5700 of half-lives, where each 8 years. Using than Let N = the amount present after x number your 50 000 function, years explain may have why an fossils older undetectable of 14 amount of C. half-lives. Reect and How you have discuss explored the statement of inquiry? Give specic examples. Statement of Inquiry: Relationships predict model duration, patterns frequency of and change that can help clarify and variability. 14.1 The power of exponentials 53 3 Like gentle ocean waves 14.2 Global context: Objectives ● Graphing sine Scientic Inquiry and cosine functions and technical innovation questions ● What is ● What are a periodic function? F ● ● Understanding periodicity graphs Transforming translations, sine and reections cosine and functions SPIHSNOITA LER Recognizing cosine transformations graphs, and nding Modelling cosine real-life = main characteristics a sin bx and y = of the a cos bx? using of sine equations of problems using sine How do you translate, dilate and reect C and periodic functions? graphs ● ● the y dilations ● ● of and How does function functions performed ● Does are the the on What ● Have real-life the of a sinusoidal transformations it? order performed ● equation represent in which transformations matter? phenomena are periodic? D scientic provided ATL more models and answers or methods questions? Critical-thinking Draw reasonable conclusions and generalizations 7.4 Statement of Inquiry: Generalizing better models relationships and between measurements can lead to methods. 14.2 534 A LG E B R A Y ou ● should use the sine already trigonometric and know ratios how for 1 to: Here is a right-angled triangle. cosine 13 5 x 12 ● nd values of sine and cosine 2 Write down a x sin Use a ● transform functions translations, using reections 3 a calculator sin Here b 45° is cos to b the nd cos graph x of the value of 37 f(x). and y dilations 5 4 3 2 1 0 5 4 3 2 x 1 1 2 3 On graph paper, sketch f(x) and a f(x) 2d f(x) 1 b 3f(x)e f( x) 2 c f(x)f Make f(2x) sure your GDC is in degree mode. The F ● What is ● What are y You sine have triangles. = used You a a Draw the can a cosine periodic the curves function? main characteristics of the graphs of y = a sin bx and cos bx? trigonometric use Exploration 1 a and ratios GDC to sine, nd cosine these and ratios tangent for in dierent right-angled angles. 1 table θ your 0° of values 10° for angle 20° θ = 0°, 30° 10°, 40° 20°, 50° …, 360°, 60° and … sin θ 360° sin θ b Find sin0°, sin10°, sin20°, etc. using your GDC. Round the values to Tip 2decimal c On graph x-axis and places paper, the and plot sine write the them graph values on of the in your sin θ, y-axis. table. with Join θ from your 0° to points 360° with a on the Make smooth curve. GDC sure is on your degree mode. Continued on next page 14.2 Like gentle ocean waves 53 5 2 Follow the 3 Check 4 For your the sin θ b cos θ Reect ● similar What is dierent? 360° how to Describe sine the gives left step 1 to draw ≤ θ ≤ 360°, a table of values and plot the the think gives the graphs each symmetry to of draw curves cosine write cos θ and down the on your range GDC. of 1 ❍ GDC sin θ graphing 720° cosine sine by about you the your and the in discuss is Use to 0° What ❍ The and Predict ● graphs domain a ● instructions ofcos θ graph curve 0° each the graph. sine will to and cosine? continue from: 360° curve. graphs have for to check same your shape. Translating the predictions. Translating cosine the graph sine 90° to graph the 90° right graph. Sine The amplitude is the height from the mean value of the function to and graphs maximum or minimum value. The graphs of y = sin x and y = cos x are also sine and have called amplitude 1. cosine The period is the horizontal length of one complete cycle. The graphs waves. of Waves y = sin x cosine its and y = cos x have period have amplitude y y = y period. sin x 1 1 amplitude y amplitude = = 180° 360° 360° of y = The graph of y = 360° 180° 1 period graph x 180° 1 The 1 0 x 180° = cos x 1 0 360° sin x = 360° passes cos x has a period through (0, maximum 0) at and (0, has a maximum = 360° at (90°, 1). 1). ATL Exploration 1 Use to what predict your 2 you the GDC Predict GDC the to to 2 know shape check shape check of your about of the your the transformations graph of y = of 2 sin x. functions Graph from the f (x) function af (x) on of y = sin x. Graph the function on your prediction. Continued 53 6 to prediction. graph 14 Models an 360° on next page and a A LG E B R A 3 4 Find the a y = 2 sin x b y = sin x c y = a sin x Predict check 5 6 amplitude Find the your the shapes amplitude y = 2 cos x b y = cos x c y = a cos x y = The of y of generalizations a sin x graph and of the = graph 2 cos x of: and y = cos x. Graph the functions to predictions. a Make of y y = = the graph about the of: eect of parameter ‘a’ on the graphs of a cos x a sin x and the graph of y = a cos x both have amplitude a y The amplitude distance of a between minimum curve the is half maximum the and 4 values. 3 4 0 360° x 180° 180° 360° 4 Amplitude = = 2 2 Example Write down 1 the function represented by this graph: y 3 2 1 0 x 90° 180° 270° 360° 1 2 3 This is a sine graph. The amplitude ⇒ = y is Compare to the sine and cosine graphs. This passes through (0, 3. 3 sin x 14.2 Like gentle ocean waves 537 0). Practice 1 Sketch 1 the graph of these functions. Label all the x-intercepts on your sketchgraphs. a y = 4 sin x Problem 2 Write a b y = 2 cos x solving down the function shown in each graph. y b y 5 3 2 1 0 0 x x 180° 360° 1 2 5 3 c y d y 2 0.5 1 0 0 x x 90° 180° 270° 180° 360° 360° 1 2 0.5 3 Four functions function(s) are shown at the a intersect the y-axis at (0, b intersect the x-axis at (180, c intersect the x-axis at (90, d has the smallest Exploration 1 Describe 2 On y = the the for geometry Add the 4 Write When graphed, choose the on axes, 0 0) 0) and and (360, (270, 0) ≤ x the graph sketch ≤ the 360°. of y = f (x) graphs Check of with when the your it is transformed functions GDC or y = to sin x with y = f (2x). and dynamic software. graph down of the y = 2 sin 2x amplitude y = to and sin x your sketch. period y = of each sin 2x graph, y = in a table like this: 2sin 2x Period Predict y = sin GDC how x. or the graph Predict geometry the of y = period sin x of changes the graph when of y = it is sin transformed x. Check to with your software. Continued 53 8 = 2 cos x y = 0.5 sin x y = 4 cos x y = 2 sin x 0) amplitude. Graph 5 y 2) 3 eect same sin2x 3 right. that 14 Models on next page A LG E B R A 6 Add 7 Repeat 8 Conjecture y Sine = column steps a sin bx and A a y = for the rule for nding y = function of are The period the The parameter b of the the and a of y y = cos x, period of a sin bx frequency, or of a why y = cos 2x function your y rule and = y = sin bx, makes x y = cos bx, sense. functions. pattern = table. explain pattern the functions is your periodic repeats repetition to graphs a cos bx, functions complete x 1–6 and cosine periodic One a for y-values is called and y number = of at a regular intervals. cycle a cos bx cycles is . between 0° and 360°. y 2 cycles frequency = 2 4 3 2 The graph y = 3 sin 2x has 1 360° = period 180 2 0 x The frequency is 2 and 180° the 360° 1 amplitude is 3. 2 3 y 1 4 period Practice 1 State the graph a y = period State sin 3x the graph = 180° and frequency 0° ≤ x ≤ of the 360°. graph Then of each check function. your graphs Sketch with a the GDC or software. b Problem 2 3 sin 2x 2 forthedomain graphing = cycle = cos 4x solving period for y the and frequency domain 0° ≤ x ≤ of the 720°. graph Then of each check function. your graphs Sketch with a the GDC or graphingsoftware. 1 1 a y = sin x b y = cos 3 Write the x 3 2 equation of a each graph. b y y 1 1 0 360° 0 180° x x 180° 180° 360° c 360° 1 1 d y y 1 1 0 0 360° 180° 1 x x 180° 360° 180° 360° 1 14.2 Like gentle ocean waves 53 9 Problem 4 Match solving each equation to its graph. x y 0.5 cos 3x y 3 sin y 3 sin 2x y 0.5 cos 0.5x 2 a y b y 1 3 2 0.5 1 x 0 180° 360° 0 180° 360° x 360° 180° 1 0.5 2 1 3 c y d y 3 1 2 0.5 1 x 0 360° 0 360° 180° 180° 360° x 180° 180° 1 360° 2 0.5 3 1 Example Sketch the 2 graph a y = 0.5 sin 3x, b y = 3 cos 0.5x, a amplitude = of each for 0° for ≤ 0° ≤ function x x ≤ ≤ on the domain given. 360° 720° 0.5 State frequency period = = and 3 = Draw 120° y The 1 are y = the amplitude, frequency period. axes for the maximum 0.5 and domain. and 0.5 minimum y values respectively. 0.5 sin 3x 0.5 Frequency = 3, so there are 3 complete 0 x 90° 180° 270° sine curves between 0° and 360° 360° 0.5 Period = 120°, so there is a complete 1 sine curve between 0° and 120° Sine Continued 5 4 0 14 Models on curve next passes page through (0, 0). A LG E B R A b amplitude frequency period = = 3 0.5 = = 720° y 3 Frequency = 0.5, so there is half a 2 y = 3 cos 0.5x complete cosine curve between 1 0°and 360°. 0 x 180° 360° 540° 720° Period = cosine curve 720° so there is a complete 1 between 0° and 720° 2 Cosine curve has a maximum at 3 x Practice 1 Write the graphing a y = c y = the amplitude, graph 2 sin 4x, for the for 0° ≤ x be for 0° y = 720° period Check of your each function, graphs on a then GDC or 360° b y = 4 cos 3x, 1080° d y = 0.7 How do ● How does Does ≤ you the x ≤ translate, the from function. can be For is a of cos of a performed in which any on obtained by reect , 0° for ≤ x ≤ 360° 0° ≤ x ≤ 1440° functions periodic function functions? represent the it? transformations function the and sinusoidal that transformation example, periodic dilate equation order function obtained cos x for 4 ● sine at x , sinusoidal the of ≤ Transformations can and domain. 3 transformations A frequency given x sin 3 ● and software. 1 C 0° 3 down sketch = of are performed matter? y 1 y = sin x graph translating 0 x the graph Soy = of cos x y is = a sin x by 90° sinusoidal to the 90° left. 180° 270° 360° function. y = cos x 1 14.2 Like gentle ocean waves 5 41 Exploration Transforming 1 Use to what 4 f(x) you predict to f(x) know how the + d about transformations transformation of y = of sin x graphs to y = from sin x f (x) + d to f (x) + d 1.1 will d y aect the graph. 0 5 5 1 2 Graph the function y = sin x + d on the domain 0° ≤ of d x ≤ 360° for dierent 0 x values of d. Investigate how changing the value aects the graph. 1 Was 3 your Verify that aected 4 prediction Repeat Use the steps Transforming 5 the by what = sin x f(x) 6 Verify 7 Repeat and that steps Transforming 8 Use y what 9 = sin ( Verify 10 that Repeat and period 3 y of = y a sin 5 and on the 6 y of y graph 8 and = f (x) in y = the the and y the sin x steps of of y = function cos x transformations to y = −sin x domain = will 0° −a sin bx graphs of ≤ + y = a sin bx + d is sin (x) + d not d of ≤ have y = graphs aect x the from f (x) thegraph. 360° cos x transformations to domain 9 Transformations The graph about = a sin bx the the = to check same and y to your amplitude = f (x) Graph to the predict how the how the functions prediction. andperiod. −cos x f(−x) = For on for y Reection: the sin x bx know of of f1(x) d about = −sin x to correct? −f(x) = f(x) of for know you x) amplitude to transformation y 1 to transformation y step value 1 you from and for y is a = x) ≤ 360° x graphs ≤ bx) of and functions reection x-axis. sin ( a sin ( sine sinusoidal −f (x) = 360° the of y of y of will to have = graphs aect check the cos x f (x) the = sin graph x your y f (x) graph. same and cosine from the = to f ( x) Graph to the predict functions y = sin x and prediction. amplitude cos( andperiod. x). functions and f (x) The of y = cos graph = f (x) x: of in y = the f ( x) is a reection of the graph y-axis. y y y = y sin x = sin x 1 1 0 0 x 180° 360° 360° x 180° 180° 360° 1 1 y = y −sin x = sin ( x) y y = y cos x = cos x 1 1 0 0 x x 180° 360° 360° 180° 180° 360° 1 1 y = y −cos x = cos ( x) Continued 5 4 2 14 Models on next page A LG E B R A Translation: For the sinusoidal functions f (x) = sin x y and f (x) = cos x, y = f (x) + d translates y = f (x) by d units in the y-direction. y = sin x + 2.5 4 When d > When d < 0, the graph moves in the positive y-direction (up). y Dilation: 0, the For graph the moves sinusoidal in the negative functions f (x) = y-direction a sin bx and = sin x (down). f (x) = a x y cos bx: = sin x 1.5 4 y = af (x) is a vertical dilation y = f (bx) is a horizontal of f (x), dilation of scale f (x), factor scale a, parallel factor , to parallel the to y-axis. the a is x-axis. the bis af(x) a > the frequency. f(bx) b 1 amplitude. > 1 y y 2 2 y = 2 sin x y = sin 2 x 1 1 0 0 x 180° x 360° 180° 1 y = sin x y 2 < a < stretch = 720° sin x horizontal 0 1 540° 2 ver tical 0 360° 1 < b < compression 1 y y 1 y = = sin x 1 sin x 0 0 x x 180° 1 = ver tical the easy to help you graphs of recognize nd y by that = 540° 720° 0.5 sin x y While 360° 1 y sin compression x looking = and at a y = cos specic sin(0.5 x) horizontal x share point many on the similarities, graph. they stretch are Exploration 5 will point. ATL Exploration 1 Sketch 2 In Reect sine and state You the can values 3 the Use graphs and x cosine = = y = 1 graphs. similarities your y of Discuss recognize at form 5 the sin x you and = using of y = noted proper dierences graphs cos x informally Now, and y mathematical between sin x and dierences y the = sine cos x and from between the terminology, cosine graphs. their 0. GDC a to cos(bx) graph + d. several cosine Generalize how functions to nd its with equations y-intercept of from the the equation. 4 Repeat step 3 with the function y = a sin(bx) + d 14.2 Like gentle ocean waves 5 4 3 The y = y-intercept a sin bx For y = + d, of the a cos(bx) y sine a + function is y-intercept d, the the is y-value the when average y-intercept is the x value = of y y = 5 Specically, the maximum graph 5 0. function: value cosine for of y graph 4 max y-intercept y-intercept is 4 is 4 3 5 + 1 = 3 3 2 2 2 1 y 1 = 1 min 0 x 1 0 2 Practice 2 3 4 5 = sin x x 1 1 2 Describe how y = cos x c y = cos x Then, + the write a 4 5 4 a Identify 3 to transform the graph of y = cos x to: 7 b y = −cos x 2 d y = cos( transformation down the of each equation of graph each from either y or y = cos x. graph. y b y x) 2 5 1 4 3 0 x 90° 270° 1 2 2 1 0 x 90° 90° 270° 450° 1 c y d y 1 2 1 0 90° x 90° 270° 450° 1 0 x 90° 270° 450° 2 3 2 4 5 6 3 Draw on the your graph graph a y = sin x c y = cos x e y = cos x 5 4 4 – + of the each function amplitude, 2 the for 0° < x ≤ y-intercept 360°. and Be the b y = −cos x 11 d y = −sin x 8 f y = sin x 14 Models + sure to period. 1 clearly indicate A LG E B R A 4 The graph of y = sin x was transformed to produce the following graph: y a Find the amplitude, frequency and period of 6 the function. 5 b Write down c Dennis the equation of the graph. 4 wants to transform the graph so 3 that its minimum value is y = 0. Describe 2 the transformation that will allow him to 1 accomplish d Write this. down the equation for Dennis’ 0 graph. x 90° Problem 5 Jawad and 90° 270° 450° solving Aaron disagree about the equation of the following graph: y 2 1 x 90° 270° 1 2 Aaron State says who Example By the is the the the is y = −sin x justify your while Jawad thinks it is y = sin( x). answer. the y transformations sinusoidal determine and 3 describing on equation correct, 2 graph, function 1 for graph. 0 180° x 90° 90° 180° 270° 360° 1 2 3 4 This is a cosine curve, form: y = a cos (bx) + d Cosine The max The amplitude, and min a, is half the distance between the Find frequency, and 360° = so amplitude the graph amplitude b, is the number of cycles the is is 3 but the translated maximum down 1 value unit. is 3 cos x and x = frequency 0. b Hence 1 amplitude unit is 3, the downward, graph hence d has = −1. 2, d = −1 into = a at between Substitute y maximum 1 shifted The has points: Since 0° the curve y = a your values cos (bx) + for a, b and d. 1 14.2 Like gentle ocean waves 5 4 5 d Example Write a 4 function that describes this y For the sine function, sinusoidal graph. 2 a 1 0 reection in x-axis gives graph as in y-axis. a the the same reection x 120° 120° 240° 360° the 1 2 This is a sine curve, reected in either the x-axis or y-axis. This x = The are 3 y-intercept cycles c = from 0° to 360°, so b = y = −2 sin(3x) or Exploration y = 2 sin( 3x) but of this y = sin(x) graph Determine which b Start with the graph of y = sin x and apply the two transformations. c Start with the graph of y = sin x and apply the two transformations the opposite Do you Repeat get step 1 for y = −3 sin 2x b y = 3 sin( c y = −3 sin Does the 3 a Repeat b Write 1 Describe a y = same the graph graphs each y = you step carry 1 down for the your out the equation ndings is these graph by transformations of of y all = and 3 cos the stating important, x to y = 3 sin 2x in x + graphs when when it 1 aect and you the = graph? 3 sin x + 1. produce. order doesn’t y the you carry out matter. 5 how to transform 4 sin x the b graph y = of y sin 2 sin x x to: 9 c y = 0.5 sin x + 4 1 x sin Describe sin of: + 3 e y = x sin how f y = sin ( 2x) + 1 3 2 2 = time? 1 d y x transformations Practice transform 2x) order Summarize transformations order. the a two to transform the graph of y cos x to: 1 a y = 3 cos x b y = 2 cos x + 1 c y = x cos + 2 2 1 d y = 0.5 cos x 1 e y = cos 3x f y = x cos 2 5 4 6 14 Models increases decreases 6 a d 4 curve because average at value. 0 ATL 2 sine has 3. Graph 1 a it amplitude, There ⇒ is 0 3 from over 0° that to 90° range. A LG E B R A Problem 3 Each For graph each function solving is a transformation graph, that identify describes a the the of either y = sin x transformations on or y the = cos x. graph and write the graph. y b y 3 3 2 2 1 1 x x 180° 90° 90° 360° 180° 180° 180° 540° 2 2 3 3 c 360° 1 1 d y 1 5 4 x 540° 180° 180° 360° 540° 1 3 2 2 3 1 4 x 180° 180° 360° 5 1 e f y y 4 2 3 1.5 2 1 0.5 x x 180° 90° 90° 180° 120° 120° 240° 360° 480° 270° 1 y y 4 5 3 4 2 3 1 2 1 x 180° 90° 90° 180° 270° 360° 450° 1 x 180° 180° 360° 540° 1 Modelling D ● What ● Have or In the In and sinusoidal show other real-life phenomena scientic models situations are and periodic? methods provided more answers questions? sinusoidal degrees, real-life the graphs y-axis curves units, you have shows the representing such as time worked sine or real-life on the with so cosine far, function situations, x-axis and the the height x-axis for x each and on has the y shown angle. axes may y-axis. 14.2 Like gentle ocean waves 5 4 7 The graph wrecking shows ball the from distance its (in original meters) position of as Distance a (m) it 6 swings left and then right. 4 From ● the The graph: amplitude is 5, so the maximum distance 0 2 the ● wrecking The negative when it ball reaches y-values swings to the from its represent left, and original the position is 5 m. distance the positive the right. 4 T ime 2 4 values represent 6 the distance ● The period To nd the when is 6 it swings seconds to (the time needed for one cycle). Tip equation of the graph: When The graph is a sine curve. It has been reected in the x- or graphing y-axis. sinusoidal Frequency b = = = with 60° the a = function, = 0 So, y = 5 sin ( 60°x) Exploration A Ferris lowest above the 1 wheel seat the against your time 2 Find the 3 Use 4 Identify 5 Determine y = the on the arranged the at ground. the ground (sec) to of as in a table. for 0 ≤ t period write ≤ the changes for the that the seats. diameter the an Ferris wheel Use a to through Graph height h (m) m and your the height drawing of motion. rotates passes 75 scale its ruler is wheel accurate describes wheel so that it takes determine each above your position. the ground 180. and down that and the the transformations order of Its ride Draw function bottom 20°. you continuously. kind positions results every As of frequency the the equation graph would relationship of need to be y to your of = graph. your graph. cosx be made described to by the Ferris transformations 6 you lungs can Find 1 seats sin x . After i get t 5 sin 60°x changes results the in Practice a 18 amplitude, your wheel = above between above Record of m y 7 has you seconds height 2 or Determine Suppose 5 1 is ground wheel. exercise, be the s b Explain c Find 5 4 8 the in make 5 sure c degrees 6 period Amplitude curves 360° 360° the modelled velocity ii of 2.5 what you period of velocity by air the iii think the air y = (in 2 liters sin per second) 90°t at: 4 s negative function, 14 Models ow equation ow s of velocities and what represent. it represents. into your to type the degree symbol the line. y = on (s) A LG E B R A 2 d Find e Draw The the the graph with the amplitude graph here of the shows waves. and Find maximum function how a a in buoy’s sinusoidal velocity. the rst 8 distance function seconds. from that the ocean models the oor changes graph. d 3 s retem 2.5 2 ni ecnatsiD 1.5 1 0.5 t 0 1 2 3 4 T ime Problem 3 Find a 5 in 6 7 8 9 10 seconds solving sinusoidal function that models the relationship y shown in each graph. y 2 5 1 4 0 3 x 90 1 2 2 1 3 0 4 1 x 10 2 3 y y 8 1 7 0 x 20 40 60 80 100 120 1 6 2 5 3 4 4 3 5 2 6 1 0 x 10 4 The height upand is in down measured the meters can be (from its modelled position by the at 20 rest) function 30 of a h(t) 40 50 spring = 60 as 70 it bounces 2 sin (60°t) + 1, where t inseconds. a Find amplitude b Sketch c Determine if position rest. the at graph the of of h(t). the function. amplitude is the same as the maximum height from its 14.2 Like gentle ocean waves 5 4 9 5 When you changes. the time ride The for sinusoidal a a Ferris wheel, relationship complete graph like your between revolution vertical your of height height the above above wheel can the be the ground ground modeled and with a this: h 8 7 6 s retem 5 ni 4 thgieH 3 2 1 0 t 4 8 12 T ime 6 a State the height b State the maximum c Determine how ground the for Determine your e Determine how f The g Find The Bal a height in number of h long is hours when of the Draw c Determine the time d Determine the height e A cross graph can level. tide the day, was next a Find b Draw 5 5 0 tide 3.3 m, high modelled a rise the for on to the wheel. Ferris wheel. approximately ground one this by 5 m above the its 8 seconds. revolution of the wheel. radius. graph. above the after complete Determine tide 12, the of the in and tide with is a function a reach Ferris the mean function h(t) sea = level one 3 sin(30°t), day at where t is the 18 and function high of for tides, the harbor the 24 tide if a 24 and at the times hours. 4 their is it at can cycle. maximum o’clock tide when hour in least the 2 cross heights. afternoon. m the above the average harbor. solving high be of 6, Determine Problem One 0, the midnight. b ship takes modeled = to above models Find the takes circular. that after t it a sea 7 be it 24 seconds board you 20 time. height meters can you height long wheel function Harbor which rst d Ferris at in 16 graph Venice, later 12 low hours this function. 14 Models the and at midnight. water that level the function. models your was tide later sinusoidal that of at Italy situation. The was height water 0.1 m. of the level at Assume water high that level can A LG E B R A Summary The of amplitude the function value. The is the to its graphs height from maximum ofy = sin x the or and mean value minimum y = cos x Reection: f (x) = period complete the f (x) sinusoidal = is the cycle. horizontal The graphs length of y = of sin = graph f (x) one x in of y the = −f (x) is a reection = cos x of the graph x-axis. y y y and = sin x y 1 y functions cos x. 1. y The For and have The amplitude sin x have period = cos x 1 360° 0 0 x 180° y y = x 360° 180° 360° sin x 1 Amplitude = 1 1 y = −sin x y = −cos x 1 The 0 of y = f ( x) is a reection of the graph x 180° 360° graph 180° 360° of y = f (x) in the y-axis. 1 y = Period 360° y = sin x 1 y y = cos x Amplitude = 0 1 1 360° x 180° 180° 360° 1 y 0 360° = sin ( x) x 180° 360° 180° 1 y = cos x 1 Period = 360° 0 x The graph of y = a sin x has amplitude a. 360° 180° 180° 360° 1 The graph of y = a cos x has amplitude a y Translation: A periodic function repeats a pattern of regular y = period a cos = sin x and of bx the functions y = a sin bx and y = f (x) + d = cos translates When is d