MYP Mathematics A concept-based approach 4&5 Extended Rose Harrison • Clara Huizink Aidan Sproat-Clements • Marlene Torres-Skoumal 3 Great Clarendon Oxford It Street, University furthers the scholarship, registered certain Press is a University’s and trade other Oxford, of 6DP, department objective education mark OX2 by of United of University excellence publishing Oxford the Kingdom in worldwide. University Press in of Oxford. p215: photopixel Amra Pasic / Shutterstock; p233: Teresa a 3Dsculptor / Shutterstock; p249: Dmitry in p264: research, Oxford the UK is and countries. 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Shutterstock; Shutterstock; Shutterstock; First / Shutterstock; 2017 Maks The / / / work. contained in any third party website referenced in How to use this book Chapters Chapte rs For m, e ach focu s Relat ion ship s Chapters for 1–3 4 –15 each on a nd focus one of t he key concept s: L ogic. on one of the t welve related concept s Mathematic s: Repre sentation, Change, Creating T he unit s. from Building of inquir y Each unit unit s Qualit y and is chapter Hence, key the se and chapter s, been within focuse s Mathematic s, opposite from and on each unit s, related a relevant one of to IB’s topic s help is Patter ns, Models, way and the of and Space, Systems by grouping Extended, ofcial dr iven global the one Standard unit focuse s combining concept s just following Each topic shows both created Cur r iculum. set Mea surement, Justication, units str ucture have Quantit y, Generalization, own different T he se IB ● your sugge sted topic s Simplication, Equivalence, a to all the create guideline s meaningful from the statement context. t welve on one from student s related of the different both concept s three key chapter s, under stand for concept s. connect and the remember them. ● Stand-alone to apply que stions ● topic s them, related and abilit y You can to T his group book MYP the simply a you topic s a the you 4 of MYP & 5 can of que stions of in in a choose, T his concept E xtended work. In your this range to applying of create skills cover s and and how debatable student s’ under standing situations. unit s dr iven by a framework. the Standard skills. Ex tended with the T he unit s, a given this may ca se, of topic book differ you context, mathematic s may and in statement s concept- ba sed table concept- ba sed to from global extends skills an work integrate which conceptual, inquir y. e stablished each mathematical factual, context. Standard work. concept context, for in i i ea sily scheme the in of already covered add practice ha s different Review scheme as teach into mathematic s scheme cur rent a s sign global statement cover s school context s, your a chapter inquir y MYP Mathematics 4 & 5 existing your each topic s Mathematics Using If to apply contextualized ● in through to content s chapter. than your from wish use unit the to the different we of topic s on Your In Most some que stions scenar ios. of in topic s can include own book may you chosen the into shows unit s ca se, your global book clearly this context and this vii scheme’s plan. global in pa ge have. wr ite inquir y in your review for Suggested The units here plan have been put together by the Access authors as just one possible way to your suggested through the suppor t website for more progress plans for structuring units: content. www.oxfordsecondar y.com/myp-mathematics Units from 1, 5, 6, 9 the UNIT 4 MYP 3 4 up & 5 of topics Standard solely book. graphs reasonable context: Identities and linear conclusions, and regression, data inferences relationships Global E14 Key transformations, inequalities, inequalities context: Identities and relationships Global 4 5 1 T opics: and E5 1 Rational indirect Global and irrational context: Globalization and numbers, fractional direct exponents sustainability UNIT T opics: 12 2 Finding patterns generalizations and geometric E8 1 from a in sequences, pattern, making arithmetic sequences Key context: Scientic and cultural expression circle involving theorems, intersecting chords, triangles and cultural expression : Logic E10 2 Algebraic fractions, equivalent methods, functions context: Scientic and technical innovation concept: Form 14 E10 1 T opics: E12 1 Evaluating logarithmic Global technical and logarithms, functions, context: Orientation in laws space of and transforming logarithms time concept: Relationships innovation concept: Form UNIT UNIT 15 8 E7 1 4 4 15 1 E9 2 Simple conditional Global E11 1 E15 1 T opics: T opics: Key Using rational Key Global volumes 13 E6 1 given sectors, E13 1 11 3 UNIT 12 1 and orientation context: Personal T opics: Key 7 8 1 13 2 concept Global concept: Form 3D 12 10 2 proportion, segments context: Personal UNIT 10 3 Circle concept: Relationships T opics: Key E9 1 shapes, problems concept: Form UNIT 3D 13 1 1 Equivalence non-linear of UNIT 14 3 T opics: 9 1 T opics: Global 3 11 1 11 7 3 E4 1 concept: Relationships UNIT Key made UNIT Scatter drawing Key are Mathematics 12 3 Global 10 2 T opics: Key and probabi lity, probability probability context: Identities concept: Logic and relationships systems, sine The and unit cosine circle rules, and trigonometric simple functions, trigonometric identities Global Key context: Orientation in space and time concept: Relationships i i i About the authors Ma rlene Tor r e s - Skou ma l a nd Mat hemat ic s In MYP addit ion E xa miner to for IB work shop of va r iou s IB HL a Higher for mer a nd cur r iculum bot h ha s taught s ever a l ha s DP a nd L evel a is MYP an for Ma rlene 20 and held Hu i z i n k Mat hemat ic s Philippine s, a l s obe en as a at ha s t aug ht MYP inter nat iona l Au s t r ia a nd the IB L ead Qualit y Educator Organization. leader, a Cur r iculum positions exper ience of for senior in MYP Sheis the MY P , re sponsibilit y teaching an reviewer and in Mathematic s her in schools. for Sproat- Clement s is Head of Mathematic s Pre s s. t hroug h s t udent is the work shop inter national at Cla r a at many year s’ A ida n Ox fordUniver sit y DP Building ha s book s, Mat hemat ic s Ha r r ison Mathematic s member te a m s. MYP Rose Chief she been rev iew DP dec ade s. Deput y Mat hemat ic s, le ader, ha saut hored including being for a nd t he she is B el g ium. IB a a nd DP s cho ol s e x p er ience g r aduate of School. in She Wellington t he He ha s independent ha s r igorous her s elf of t he College spent schools student-led Mathematic s. MYP He eA s se s sment s in the his UK, career where he an in helped for to World Br itish ha s approache s IB to promoted the develop lear ning the pilot Mathematic s. IBprog r a m. Topic opening page Global some Objectives – How to stand this Making and context: for Using Inquiry inferences standard Identities about data, given the to – the Approach Learning taught SPIHSNOITA LER topic. ATL forms F this context. are set in You of the standard relationships Making Using may wish your own the normal about standard distribution normal deviation of a data context set? the to enga ge is the meaning of student s. ‘standard C distributions and wr ite deviation your the inferences to global questions deviation How Understanding formulas? mean Can samples give reliable results? D Using mean unbiased and estimators standard of the population Do we want to be like everybody else? deviation Inquiry questions the and Communication inferences and draw conclusions debatable topic. explored questions in this 4 3 topic. 12 3 Unit plan – shows E4 1 Statement of Inquiry this unit. for Y ou may the write your wish own. topic s Standard Extended can help to and clarify representing trends the and book s relationships among individuals. that you teach a could together 7 6 i v in Statement of Inquiry: Generalizing to – factual, conceptual, ATL Make in unit this mean deviation dierent and formula the this from crowd Objectives concept in topic. Global Key out E4 1 the in – the mathematics covered contex t que stions unit. as Learning Each features topic has three ● factual ● conceptual ● debatable Problem solution inquir y solving is not highlighted sections, exploring: – questions where the immediately in the 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 11) Q in the your step and points A (10, 6) M and A and nd the between midpoint the midpoint. 4 to D (19, using have formula and Generalization small B (2, groups facts and to learning inidvidually , 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 ) 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 ( ) to enable verify and ( a d) you to their learning Find Let the M be is the of A(3, midpoint of 6) and B (9, explain 18). examples the a clear solution and AB Use the midpoint formula M = 12) 3 1 midpoint Find the 2 Find the 3 a Plot b Find midpoint the points the on quadrilateral 7 0 of A(14, of C (5, A(2, midpoints Comment your 7), of 6) and B (18, 13) and D (10, B (3, 10), C (6, AC and answers to Practice questions terms, to practice 8). 11), and D (5, apply b. Explain what this shows them command to the skills unfamiliar taught and how to problems. about 3 Logic the Technology and objective highlight explain in an to an IB Assessment students Exploration or how to satisfy Practice. icon Using technolog y range of allows example s, or to student s acce s s to discover complex new idea s idea s without through having examining to do lot s of a wider painstaking hand. icon D ynamic student s IB ABCD Objective by using 8). BD part written 20). Objective boxes T his show method. 6 + 18 Practice work questions. . M (6, inquir y 1 midpoint 3 + 9 the generalization? Worked Example and predict? shows where Geometr y should not student s Soft ware use could (DGS) technolog y use or are Graphical Computer indicated Display Algebra with a Calculator s Systems (GDC), (CA S). cros sed- out Place s where icon. The notation used throughout this book is largely that required in the DP IB programs. v Each topic ends with: Summary The standard dispersion deviation that gives an is a measure idea of how of Using close data original how A data values representative small standard are the to the mean deviation mean, is of and the values are close to shows the that mean. The of values all the of the x deviation original means Using Σ the this are the same as the in x f the formula sum of all the x of all the mean the values of a set of divided values by frequency table divided by is the , total the sum frequency. to data calculate the presented in standard a deviation frequency table for is: Summary of the points The normal distribution with most is a symmetric values close to the mean the values. tailing frequency o evenly graph is a in either direction. bell-shaped Its curve. practice Number questions 1 and 2 the data provided is of strawberries on each plant fed with for special the discrete values. and In of key notation, Mixed set data. sum of a of n number a values distribution, , of units x is mean the units discrete standard the so data. A data notation, the strawberry plant food: Mixed population. 14 15 17 17 19 19 12 14 15 practice – 15 summative 1 Find the each data mean and the standard deviation of Analyze 2, b 21 3, 3, 4, 4, 5, 5, 6, 6, 21 kg, 24 kg, of using to the nd whether special there strawberry is an plant 25 facts kg, 27 kg, 29 kg Bernie recorded hamster ate the each weight day. Here of food are his in of the food. 6 3 kg, data assessment eect a the set: grams and skills his results: learned, including c x f 3 2 4 3 5 2 Day Food a (g) Find the the 1 2 3 4 5 6 7 8 9 55 64 45 54 60 50 59 61 49 mean weight of and food standard the deviation hamster ate b Interval Bernie range assumes that his hamster’s in a the 9days. d questions, and questions of over problem-solving of contexts. food Frequency − Review in The art ancient culture to and create context of origami involves models. has folding Some roots at models in sheets are Japanese of The resulting paper designed creases are A illustrated in this B diagram. C to E resemble just animals, celebrate the owers beauty or of buildings; geometric others design. Review in context D – summative F assessment within the questions global H context G The artist for the topic. Z thinks lengths FH and DY are equal. 1 b Explain why EX EG. 2 Reection Reect and statement How have v i you on discuss explored the statement of inquiry? Give specic examples. inquir y of the Table of contents Access your suppor t website: www.oxfordsecondar y.com/myp-mathematics Form E1.1 Space What if we Dierent all had eight ngers? • E9.1 bases 2 Another 3D E9.2 dimension • Orientation Mapping the 167 world • Relationships Oblique E2.1 Multiple doorways Composite triangles 183 • functions 21 Change E2.2 Doing and Invserse undoing • E10.1 functions 35 Time Log E10.2 for a change • functions Meet the 202 transformers • Logic Rational E3.1 How can Vectors we and get there? vector functions 216 • spaces 54 Equivalence E11.1 Unmistaken identities • Representation Trigonometric E4.1 How to stand out Data inferences from the crowd identities 233 • 76 Generalization E12.1 Go ahead and log in • Simplication Laws E5.1 Super powers Fractional of logarithms 249 • exponents 98 Justication E13.1 Are we very similar? • Quantity Problems E6.1 Ideal work Evaluating for lumberjacks involving triangles 264 • logs 108 Models E14.1 A world of dierence • Measurement Nonlinear E7.1 Slices The of pi unit inequalities 282 • circle and Systems trignometric functions E15.1 Branching out • 124 Conditional probability 299 Patterns E8.1 Making it all Arithmetic add and up Answers 315 Index 350 • geometric sequences 145 v i i What if we all had eight E1.1 ngers? Global context: Objectives ● Understanding Scientic Inquiry the concept of a ● number F system ● Counting ● Converting in dierent numbers bases from one base to MROF Using How have What ● How operations is a can number you in dierent How other ● D are written in base? write numbers mathematical bases Communication understanding to interpret Would base ● 2 been in other bases operations intercultural numbers bases? ● Use innovation questions ● C ATL technical history? another ● and communication similar in you base be to operations and dierent in from 10? better o counting in 2? How does form inuence function? N U M B E R Y ou ● should use the already operations of know how addition, 1 Calculate subtraction and long multiplication in base 10, without a to: a 10 442 understand place value 2 27 ● How ● What ● How Humans record of language, these but or all cultures you the nd the values Egyptian of symbol total all numerals a a 10 887 d 14 078 7891 in system of down the value of the 5 × 71 in: b 511 002 d 1.5 bases in in history? other bases? to down a or in . the forms was the word dierent Each dierent of way, of notation Egyptian an additive dierent symbols the a quantity. ancient a 5, word tally: same has ways write symbol a 43 15 written numbers you dierent use b diagram? used The value the this the been dierent number number Each in even use hand: base? write would have number. hieroglyphic number written maybe dierent numbers many bugs the in you represent represent system. can could represents they Dierent to have You a How green might “ve”. is used numbers. number You have have 762 351 c Numbers × Write a F + by calculator c ● these value number by and adding together. these symbols: Green are called stroke heelbone 1 10 coiled shield bugs sometimes green stink rope bugs, as they 100 produce odor if a pungent handled disturbed. lotus ower pointed 1000 The number nger 10 000 11 is written , and 36 is tadpole scribe 100 000 1 000 000 written . E1.1 What if we all had eight ngers? 3 or Reect and discuss 1 ATL ● Write each number in Egyptian numerals: 99 ● Write these ● What are the advantages ● What are the disadvantages? Our number The position The two numbers system, of a numbers represent the often digit below same as ordinary of the called tells you have the Egyptian in Moving The the left, third furthest the right second column number numerals, system? is a place value system same four digits, but digits do not always amount. 3 digit numbers: value. 3642 A (decimal) Arabic its 10 240 4623 thousands column column represents and 3 represents represents collections of units individual collections ten tens: of the objects: ten units units: hundreds the tens column column The pattern continues: each column is worth 10 times more than the column to The number 4 364 actually represents a collection of that many its right. objects: hundreds tens units 3 6 4 E1 Form N U M B E R Reect ● ● and Does the Does it The Our symbol represent Roman does the column the to have system of dierent is do known each values in the numbers have need as place a a symbol symbol decimal value • • 10 thousands × to for (also column 10 × hundreds as is 10 tens 2 10 In make binary represent base ten × a (base place two) • value ten, times • or the so why denary) value of the each column • • 2 worth × sixteens 2 eights 4 number is twos 2 a set the × number column base. to its right. 2 units 1 2 represents point natural 2 fours 3 • 10 twice × 2 10 111 any • 1 10 with • tenths 0 10 system 2 binary zero, 10 units 1 10 × The 2051? zero? decimal can and right. 3 You 205 dierent? not system × • 2 something value value its 0 numerals place number because discuss • • • 0 2 2 containing: 2 sixteens eights fours twos units 1 0 1 1 1 The subscript 2 means that the number 10 111 is written in base 2. Tip 2 Base 3 - ternary, or trinary Computer lots 8 of GB 20 logical contexts (gigabytes), GB, etc. systems relating Also, 16 use to GB, base 2. computers. 32 whereas GB, the 64 prex This For GB kilo is why you example, and so on, usually see SD rather means powers cards than 1000 of which 10 (e.g. 2 in Base 4 - quaternary Base 8 - octal Base 12 store GB, there are - duodecimal 10 1000 so meters there are in a 1024 kilometer), bytes in a in computing, kilobyte. the term kilo means 1024 (2 ), Base 16 - hexadecimal (widely used in computing) E1.1 What if we all had eight ngers? 5 The base number Base 2 of has Example Find a number system the two has. system Base unique 10 tells has symbols, you ten 0 how many unique and unique number symbols symbols, 0 the through 9. 1. 1 value of 12 011 in base 10. 3 4 3 3 2 3 1 3 0 3 3 Write 81 27 9 3 the powers of 3 above the digits, 1 0 starting 1 81 2 + 2 × 27 = 12 011 0 + a 1 = 1 at the right-hand = 139 Add up the parts Use that make up the value of each 10 111 subscripts to show binary b number in base 11 001 c each number to base b 21 002 2 is the 22 101 c 412 3 human 332 e 64 5 f 9 being is these numbers 1010 in ascending 100 011 4 The number Describe 1111 3 1 101 011 000 the order: 1011 2 = 5 856 2 a 10 relationship between 1 101 011 000 and 110 101 100 2 b Find the value of 2 1 101 011 2 Exploration 1 Use this table 7 1 to explore 6 3 5 3 2187 4 3 729 questions 3 3 243 a g 2 3 81 to 1 3 27 0 3 9 3 3 1 7 a Explain how the value of 3 tells you that the number 1038 will 10 have b 7 1038 digits = in 729 10 base + how 3. 309 10 Explain this . 10 sum tells you that the rst digit of 1038 in base 3 10 will be 1. Continued 6 aware that counting. solving – 4 from without 77 8 Problem pleasure mind experiences 5 counting, Write base. 10. 3 3 the 1 101 101 2 the d number. 10. Music Convert a the 1 2 2 side. 1 10 Practice Find + 3 139 3 1 3 1 with E1 Form on next page Gottfried Leibniz it N U M B E R c 309 = 243 10 + 66 10 Explain 10 how this sum tells you that the second digit of 1038 10 in d base 66 < 3 will also be 1. 81 10 10 Explain how this inequality tells you that the third digit of 1038 10 in e base = 66 3 2 will × be 27 10 0. + 12. 10 Explain how this sum tells you that the fourth digit of 1038 10 in f base 3 will Continue be the 2. process to nd the value of 1038 in base 3. 10 g 2 Check Use a the your solution method 1000 to in base step by 1 converting to 2 The ● Start the b 513 with the number, remainder If ● Repeat > new 4 units ● Here down 0, base 10. base 3 c 673 the replace from digit and n. the then Divide to base 4. 10 digits of working n by b a to and number the nd n in base b, left. the quotient q, and r value n the remainders the to produces the Write q algorithm with ● into 10 following starting back convert: 10 3 it algorithm with of r the value beginning to is the left used to with of of q ; the any new you convert otherwise value have 1038 stop. of n, already into base and record written down. 3. 10 n ÷ b n q r 1038 346 0 346 115 1 115 38 1 38 12 2 12 4 0 1038 ÷ 3 346 = ÷ 346 3 = r 0. 115 The r 1. units The digit 3s is digit is 0. 1. Change Change n to n 346. to 115. 2 115 4 1 1 1 0 1 ÷ 3 = 38 r 1. The 3 38 ÷ digit is 1. Change n to 38. 3 3 = 12 r 2. The 3 digit is 2. 4 Read the 12 ÷ 3 = 4 r 0. The 3 4 ÷ 3 = 1 r 1. The 3 digit is 0. digit is 1. q = 0. number 5 in base b from upwards here: 1 102 110 6 1 Use a the algorithm 1000 10 to base 2 to ÷ 3 = 0 r 3. The 3 digit is 0. Stop because convert: b 513 10 to base 3 c 673 to base 4. 10 E1.1 What if we all had eight ngers? 7 Practice 1 Convert 2 999 to: 10 Use a base 2 b base 3 c base 4 d base the prefer 2 a Find the value of 472 in base bases. Hence nd the value of 472 in base 5. 8 3 By rst given a converting to base 10, nd in base 7 b 431 5 d the in 1011 in 8868 base in 6 e base 3 h write the 1331 Determine you know. Use your in 101 101 same Benito: 2 c base 8 which students’ Determine d Find the values of to the part numbers, of your in number A bottle A shipping 2 base 4 in dierent 3 Claudio: a, to a, b, c and students and list any the such other value that the to a, for 1331 b, c and = 2061 d to nd the value of the d = you in Explain can gain 8 1000 how from ascending 3213 = order. 1000 c number packs 12 bottles will hold to 12 a box. There are 12 in d base 10. in each crate. bottles in each shipping orders 600 bottles. boxes in a crate. crates. bottles customer base. b of Find the number container. of crates and boxes to order. customer single orders bottles on page price 81 for 9 Calculate basic per bottles. this Determine shows four appropriate bottle the number of complete E1 Form boxes order. is dierent values orders, for the with shaded some information cells. €1.40. Continued 8 base b of The in 2 container table 9 d largest number missing. base Donatello: information numbers possible d used number The in c the A 2468 3213 the and 4 factory this 2 bases: Determine full 110 213 i Determine A base 9 2061 four minimum answer Exploration 1 in 4 a Use 214 f b answer c e the solving students the base 110 111 a b in 2 Alberto: a numbers 2 Problem Four these 6 9 4 of 8 2 g value base. 223 to numbers 10. 8 b method on you 5 next page convert to dierent N U M B E R Customer Total name ordered Total Notes Containers Crates Boxes Singles cost Mr a n/a 0 5 0 0 b c d e f g 4 4 1 0 €8400 j k l m n Antinoro 10% discount Mr 6000 on Drouhin complete containers i (% Herr discount h Müller on the whole order) Mrs 1500 n/a Symington 5 An employee containers, repeat the 0 singles a Write this b c could Mr Why ● When 1, Base 2, do because since and every written as all orders singles, time, so the an are made company order of 3 of a does crates, number not 7 of need boxes to and 370. Mr notating Drouhin’s is the 12 4, 5, 6, problem and Herr Müller’s orders using these you 12 uses 7, 8 write ten and writing most involve number Mrs in to relates Symington’s used to writing numbers order in this way. as use a base base? 10 to What count? makes the use? symbols twelve two numbers way commonly Similarly, requires this 3 dierent 9. in commonly convenient both symbols in people number orders bases. discuss think a the number (duodecimal) When extra you (decimal) 3, 12 the and number 0, how Describe 10 boxes Antinoro’s, non-denary ● Base be that convention. Reect ATL crates, headings Explain in suggests base to 2 describe uses symbols, two but the whole symbols: you cannot 0 numbers: and use 1. ‘10’ or ‘11’ digits. bases greater than 10, letters are used needed. for the Sometimes lowercase a In base 12, the symbols are 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, A and and b letters are used B. instead A and E1.1 What if we all had eight ngers? of uppercase B. 9 Example Find the 2 value of A3B in base 10. 12 2 1 12 0 12 12 144 12 1 A 3 B = A3B (10 × The 144 + 3 × 12 + 11 × letter A represents 10, and B represents 11. 1) 12 10 = 1487 10 Example Find the 3 value of 500 in base 16. n ÷ b n q r 500 31 4 31 1 F 1 0 1 500 31 500 = Convert 1 to base a b 301 c the value in base 190 b 2766 e c The symbol ÷ 16 = 0 r 1. The and (base other Explain d Give why 10 the 20 10 51 966 16) digital there number your digit for digit G0 f 64 206 10 codes are often used as passwords for home Wi-Fi services. are 256 possible 2-character passwords in hexadecimal. 10 Find 16 solving Hexadecimal b units 47 806 10 Problem a The 16: 10 48 879 hubs 15. 4. 12 10 3 r BAA 16 10 d 1 r 10: 210 Find = 31 3 12 2 16 = is 15 4. is Change F. n Change to n 31. to 1. 2 16 Practice a 16 1F4 10 1 ÷ ÷ of answer possible to a E1 Form 10-character suitable degree of hexadecimal accuracy. passcodes. is 1. Stop because q = 0. N U M B E R Counting US in President Abraham “Four score a nation, new men A is are the and seven a group number ‘quatre-vingt-dix’ Objective iii. move Dierent C: number our liberty, or set system, or ‘four Mayans dierent bases show and that Exploration The ago in of 20, 80 is used up 19. to had the For Write The For the twenties forms symbols you a can of base 20 tell the and 1s dierent to forms and or continent that all seven’ ‘four is 87. twenties’ and 90 representation of dierent system, but representation. symbols and In this number bases. only three and symbols: 5 in combination leave bars 4, 0–19 do in 10, full base wrote enough one and the in the 19 in Mayan purpose Eectively, digits say, = same 10. space between, with 14 6 to create numbers vertically between a 10 units (two 11 in the = in Mayan are the ascending digits so horizontal place and 16 numerals. they place one place place 1 20 s 1 20s 1 1s order. that bars) in numerals Mayan the It they and as the digits. was could 105 twenties (two place). × 20 ) place 5 place 0 place 2 (1 this 2 s 20s on proposition ten’. 2 20 score 1 = they dierence horizontal ‘four between number 3 0–9 value, important so mathematical are move symbols from from place forth the 3 numbers numbers numbers to began: example: = 1 brought dedicated ‘quatre-vingt’ 0 They fathers and Address” Communicating between Exploration, years “Gettysburg equal.” means French Lincoln’s conceived created ‘score’ In ATL 20s 13 2 + (1 × 20) + 1 = 421 (5 × 20 ) + (0 × 20) + 13 = Continued 2013 on next page E1.1 What if we all had eight ngers? 11 2 Find the value of these Mayan a 3 Write 4 numerals: b these numbers in c d Mayan: a 806 b 2005 c 10 145 d 16 125 e 43 487 f 562 677 g 100 000 h 2 Find the value of this sum, showing all your million steps: + The Mayan people kept stingless bees for honey. Technically, stingless have Express your 5 Explain why 6 Compare answer in Mayan notation as well as in base Mayan system is part additive and part place value. a are sting only our base 10 number system with the Mayan system and any advantages Per forming C ● How are dierent In or a calculation + 8 9 2 3 7 4 you add you a digit the units, number and one has over the other. operations operations in base in other bases similar to and 10? this: then the that operations mathematical from greater ‘carry’ 12 like disadvantages the than 10 to tens, or the E1 Form then equal next the to 10 hundreds. (the column. base) When you the write addition down so small from about one as that is painful write as down do but 10. they the bees stingers the gives units a mosquito bite. N U M B E R You can add ‘carrying’ when Example Find the numbers a in other number is bases greater in the than same or way equal to as the decimal base numbers, number. 4 value of 465 + 326 7 7 Units column: 5 + 6 = 11 . In base 7 this is 1 seven and 4 units, or 14 10 Write 4 in the units column 7 and carry a 1 Sevens into the column: sevens column. 6 1 + 2 + = 9 = 12 10 7 2 7 column: 4 + 3 + 1 = 8 = 11 10 So, 465 + 326 7 1124 7 Reect You = could 7 and work discuss out 465 + 4 326 7 ● converting 465 ● adding ● converting For you method the and ‘borrow’ Example Calculate a 326 result you 10 in adding, as in Example 4, or by: into base 10 7 would subtraction, by 7 7 Which 7 back you can to prefer? ‘borrow’ base base 7. Explain. the base number, in the same way that 10. 5 783 9 267 9 7 > 3, so you cannot subtract 7 from 3. 1 Rewrite 3 units, same 7 8 as 8 3 as nines 13 7 7 13 7 9 Continued on next 7 = because eighty-ones nines 7 9 13 3, and units, Find 7 by and 7 writing is the eighty-ones. it in base 9 12 9 10 7 10 = 5 10 = 5 9 page E1.1 What if we all had eight ngers? 13 10: 7 6 = 1 in base 9 and in base 7 So, 783 267 9 4 124 + 321 8 453 + 261 c 563 8 + 241 8 + 757 8 8 b 341 6 153 6 c 1231 6 402 6 6 Calculate: a 115 23 8 + 45 8 b 2231 8 125 7 216 7 c 8463 7 + 728 9 541 9 + 18 9 9 Calculate: a 92A1 + 4436 12 Vorbelar b 10 000 12 Problem 5 77 8 231 6 4 b 8 Calculate: a 3 9 Calculate: a 2 = 515 9 Practice 1 = 2 10. 123 12 12 solving the alien does not count in base 10, but in order to make things If easy for us to understand, she uses our base 10 symbols in the usual you can’t She calculates 216 + 165 and obtains the answer think count, the value of 216 165, giving your answer using Vorbelar’s three pocket giving two and discuss performing added or subtracted Exploration There are a many calculation, are in the is it same important base? Why that or the why two numbers not? of setting out the calculation 742 × 36 10 Here is one being 4 ways 10 approach. First multiply with 6 × 2 the = 2 12, in so the the top row units write 2 by 6, one column at a time, starting column. in the units column and 1 in the tens column. Continued 14 E1 Form of in your and Fido then only them. 5 – When dog base. biscuits Reect try 403. putting Find dogs order. on next page Phil Pastoret 5 N U M B E R 6 × 4 tens write 6 × 7 2 in = calculate tens × 2 = 3 tens × 4 tens tens × 7 the 742 tens, 1 = in × × completes Add together above the to to write 4 the so in 3 1 add the 2 Try times to use write 6 in the Here Use is a the so tens column and to the 2 in the column. write column. 2 in the hundreds thousands. = 21 and × 3 two thousands, write 2 in so the add ten 1 to the thousands 1 in the column. tens. parts calculate already 727 × found. 736 . Explain how you have 10 tables. the same method to calculate 727 multiplication table to help table you in base calculate × 736 . Describe any diculties. 9 9. 727 × 9 4 2 tens 9 3 the thousands 10 used in tens. hundreds, the 742 4 column. 6. so 12 column This method add hundreds, and hundreds thousands Use 6 and so 42 742 3 column 1 = column completes Now 3 tens, hundreds hundreds hundreds This 24 the 736 9 × 1 2 3 4 5 6 7 8 10 1 1 2 3 4 5 6 7 8 10 2 2 4 6 8 11 13 15 17 20 3 3 6 10 13 16 20 23 26 30 4 4 8 13 17 22 26 31 35 40 5 5 11 16 22 27 33 38 44 50 6 6 13 20 26 33 40 46 53 60 7 7 15 23 31 38 46 54 62 70 8 8 17 26 35 44 53 62 71 80 10 10 20 30 40 50 60 70 80 100 Explain why you need this table for long multiplication in base 9. E1.1 What if we all had eight ngers? 15 Practice 5 1 multiplication Here is a in base 5: × 1 2 3 4 10 1 1 2 3 4 10 2 2 4 11 13 20 3 3 11 14 22 30 4 4 13 22 31 40 10 10 20 30 40 100 Use a it to complete × 123 Copy these multiplications: 24 5 2 table b 401 5 and × 133 5 complete × 1 2 1 1 2 this multiplication 3 c 213 5 × 1310 5 table for 4 5 10 2 4 5 10 2 4 12 4 4 12 5 5 10 10 base 5 6. 20 3 Hence a 20 complete × 155 these multiplications: b 212 6 Problem Find 40 23 6 3 40 two × 315 6 6 solving numbers (both greater than 1) whose product is 1215 6 Because long multiplication multiplication multiplication to convert convert the Division easiest the or that How use the 16 to to you base 2 its 10 E1 Form o for most table write cases out it is multiplication, facts, a easier and then base. and then counting table facts, divide so it is usually them. in of their through exists system: base 2? function? most pass memory counting in the can numbers inuence that but You multiplication base (binary) signals computer’s for need, required better form multiplication tricky. perform binary be knowing quite you 10, the to on is base base knowing at does electrical symbols the back on peek Would As for relies bases numbers ● the ‘o ’. two relies ● Computers is table numbers convert A D dierent numbers also to in 0 in and operations. the two 1. computer states (on One chips or reason are o ) it for either uses this ‘on’ just N U M B E R Reect ● Create tables’ ● Try ● Can You and and long with multiplication in the using may numbers a you nd it new to work bases, Hexadecimal represents a passwords is hand 2 binary. Can you multiplications in 4 in a to or base because steps. ‘learn routers in so in your times 2. base there are more fewer is in why often lot use of digits, symbols In have in numbers fewer digits. hexadecimal example, That example) a digits. symbol For 2? are numbers each digits. binary. for base There have and because binary 0 011 1111 and of 2 symbols, 4 in 110 110 100 numbers computers bits, × lot thus more 3F in built-in digits 0-9 and the you Draw 10 show represents number to nd nger 32 5 nger/thumb diagram Find a slow and are modems diagrams extended help some involves converts (in in A-F. This 1 of table 1 011 100 110 bases, used Exploration An out there string hexadecimal These perform multiplication small 6 base? multiplication with larger letters discuss in 10 number diagrams b way of counting 1 and zero. base the a represents to show 68 10 in binary each by binary curled This represented in a diagram the using one your ngers. represents represents diagrams below. 0. one. It may rst. of c these base 101 10 10 numbers d in binary: 250 10 E1.1 What if we all had eight ngers? 17 Reect ● Is ● How counting in ● and is in base counting base When discuss 2 in on 7 your base 2 ngers on your a more ngers ecient more way dicult of counting? than counting 10? might it be useful to try to count in base 2 on your ngers? Summary Our number system, often called Arabic numerals, The subscript 2 means that the number 10 111 is 2 is a place tells you value its system. The position of a digit written The Our or number base place ten, to system or value column is also denary, column its is known because 10 times the the as decimal, value value of of base unique each has the Base 2 10 × 10 × 10 × thousands hundreds 3 tens 2 10 10 • units 1 10 • tenths 0 • 10 In 10 A unique has the system number number two make a place value unique tells you system symbols: symbols: 0 0 how uses. Base through and many 10 9. 1. base. In system binary, or write used numbers for the in extra bases greater symbols than 10, needed. 12 B the (or symbols are sometimes 0, 1, 2, 3, lowercase 4, 5, letters 6, a 7, and 8, 9, b). point with can base add way as numbers decimal in other bases numbers, in the ‘carrying’ when any a number you are base and same natural number • You can a 1 decimal You of 10 letters • 2. symbols ten When • base right. × • in value. two, number is greater than or equal to the base each number. column is worth × • • twice 2 × sixteens • the column 2 eights × fours to 2 its × right. 2 twos units • • For division it usually is 4 3 Mixed 1 Find 2 2 1 2 base 10, the value in base 10 of: 1101 b answer back 3 can 1 000 101 d 1221 You 45 3 12 000 f 4523 8 34 337 h 11 the 100 value in in base the base 2 specied b 100 in base 4 d 255 in base 3 f in base 2 in 1689 base 12 h base 5 456 in base numbers to the base in the question. measure One angles degree = in 60 degrees, minutes minutes or 60′, and and minute degrees, = 60 15 seconds minutes angle or and 60″. 30 45° 15′ 30″ = seconds. Convert these measures: a 42.8° into b 90.15° c 2.52° d 25°15′ e 62° 30′ 30″ into base 10 (including a decimal) f 58° 12′ 20″ into base 10 (including a decimal) degrees, minutes and seconds in base 12 j degrees, minutes and seconds 4 2785 in into degrees, into base 10 minutes and (including a seconds decimal) base 12 Calculate, in the giving your answers in the base used question: 10 in base 16 10 l 15 342 in base 16 a 1101 1011 2 E1 Form + 2 10 c 18 into 12 10 10 1049 in 10 10 k 3 8162 10 i base 10 1008 271 in 10 10 g the convert of: 100 10 e then 4EA8 Find c calculations, 18A9 16 a the 2 8 2 convert base, 110 110 3 i dierent practice 2 g to a 2 one e ecient in 0 2 2 c most do seconds. a multiplication • to 2 and 1001 b 11 101 2 + + 2 10 111 2 + 1 101 101 2 101 101 2 N U M B E R d 122 + 2101 3 f e 2122 3 3012 + 10 + 20 012 3 Problem 3 solving 332 4 d 4 Ronnie has 331 213 grams in weights. 4 g 33 010 + 312 212 4 + Donnie 101 4 has 565 + 718 12 i 1A91 12 + AB0 + 10B8 12 l k 6E 12 F00D + + wishes Ronnie and the out weights. the Donnie same combined, amount using 16 the weights FACE she has from only her sets. three of Remembering each type of that weight, 16 Calculate, in weigh AC determine 5 to 12 16 16 in 3302 12 as j grams 4 4 Connie h 231 232 giving your answers in the base the weights Connie should use. used e question: Ted weighs out grams. 1330 Ed weighs out 4 twice a 11 011 101 2 b 111 011 2 that 10 110 111 2 e 3011 2210 f that 3 44 125 1045 h B791 6 FEED 89A0 12 the he 9 A US current time was 10:45, use addition 2 combined. as Remembering only the three of weights each Ned type of should weight, use. committee monetary system. decides All coins to streamline will be phased except to nd the time that minutes from for 1 cent, 5 cents and 25 cents. All and bills (bank notes) will be phased out is: and b Ted 16 subtraction 35 has congressional existing a and 12 out If Ed BEEF 16 6 twice 6 the i as determine 5150 6 6 out 102 4 50 112 weighs 2 3 231 4 g d 2 Ned 11 101 2 much c amount. replaced with bills valued $1, $5, $25, $125 and$625. now 1 hours from now a A mathematician suggests that the dollar 2 should c 3 hours and 40 minutes from 1 hour and e 6 hours 19 minutes 50 100 cents minutes Calculate, giving your answers in the base the worth 125 as it is cents, currently. Suggest reasons this why might be the a mathematician good idea. used ii in be ago thinks 7 to ago i and revalued now not d be Suggest reasons why it might not be a question. good b Find idea. in 540 base 5. 10 Either create multiplication tables like the Hence ones in Practice 5, or convert the base 10 and then convert c 110 × 10 2 b 1011 2 × 11 2 c 1101 2 × 2101 × 21 3 e 14 3 × 23 5 A set of weights f 24 5 contains × Find powers of 4. There in the set. The three lightest heaviest is 16 384 in grams Find the total Rania of each weight the one of the is 1 g, Write create there down of these weights, size a the total are three above weights weight only Find the value three of base 5 and 246 in base 5. $732 a to her payment credit of card company. $246. the total amount and the need to least outstanding number of (still notes she repay the amount. six weights: In real of the next of of life, bases, but systems have do not use combinations of wanted why to weights, size and this you 26 in nd would the total one of the next two of the size notes size follow irregular patterns. For example, in that. g. each 2313 monetary two would use Remember type of UK, valued to that there £5, Suggest base £10, to £1 £20 reasons convenient weight. are and and why use a it £2 coins, then be perfectly not be regular base above. 10. relevant weight size, after of if you three three of 1 the notes £50. would 4 Explain under 10 owes suggested c $540 and the b somebody size that and give g. weight smallest in makes regular of to that e a that 5 would the need 732 owed), weight notes 131 5 weights are of system. 10 Find are number 2 She 8 would new 101 2 d d smallest back. the a the numbers you to nd g next that. E1.1 What if we all had eight ngers? 19 as Review in In and the 1960s context 1970s, NASA’s Pioneer and 3 The scientists also encoded some information ATL Voyager beyond in case life the the solar craft forms. they or missions system. was could could Each tried be be spacecraft to by travel by messages extra-terrestrial choose universally measured to contained intercepted Scientists hoped which launched things that about our about quantities measured, whereas communicated, can aliens. be If an alien culture has a number system, there good chance that they will have some sort value system. They will probably have of whole of prime to include numbers, numbers. One and maybe suggestion an for year. per The prime in a numbers binary Write are: b List c Hence list For the the 10, to communicate binary. 11, the The rst 111 and 101, values of these next ten the prime a rst 15 prime and table in vertical Here these the the — some symbols our Earth many times while orbiting information the about solar the system: length Day length Ear th days 1408 Ear th hours 1011. Venus 224.68 Ear th days 5832 Ear th hours numbers in Ear th 365.26 Ear th days 24 Ear th hours Mars 686.98 Ear th days 25 Ear th hours denary. in Jupiter 11.862 Ear th years 10 Ear th hours Saturn 29.456 Ear th years 11 Ear th hours Uranus 84.07 17 Ear th hours Neptune 164.81 16 Ear th hours binary. Ear th years are did not known — they and used Calculate and in year. number Give your of Earth answer hours in in a denary. and b given the to |. sequences years use only horizontal Ear th binary using Hence Mars nd year. the number Give your of Mars answer in days in a denary. |. whether — or | represents 1. Find (to the nearest whole number) the Justify of Mars days in a Mars year in binary. answer. Describe and 365 how axis some 87.96 number your own Mercur y c Determine is that each numbers numbers scientists symbols Instead, lines: are its gives Year Mars humans. (roughly) that in solving messages, 0s; quantity ‘days’ rst a 1s of than units message the in One rather require awareness ve numbers not. number has information counted, an (decimal). Problem 2 in down denary be does the because around Planet might is be measurements Earth year rotates planets idea counting can used of sun. place that They is it a system. because counted planet’s days 1 solar |, each the next sequence three and predict, using — d terms. Find, for in each binary, of the the number other outer of days planets in a year (Jupiter to Neptune). a | , |— b | , | , c | , || , —, |— —| , |— — — —, ||— —| e |—, || , |—| , |— — —, ||—| , Describe when 20 |— —| , ||—|| , E1 Form |—|— — any problems you would encounter |—|—| —| for trying Venus. to perform a similar calculation Multiple E2.1 Global doorways context: Objectives ● Performing function ● Using Inquiry operations with functions, including function composition to solve questions ● How ● What ● How C to do you add and subtract functions? is function composition? can model you use function real-world composition situations? functions ● Draw innovation real-world D ATL technical Does a composite function have a unique decomposition? Critical-thinking reasonable conclusions and generalizations 21 SPIHSNOITA LER Decomposing and F composition problems ● Scientic Y ou ● should draw already mapping know diagrams how for 1 to: Draw functions a mapping represent the the diagram function to shown on graph. y 2 0 6 4 x 2 2 4 6 2 4 6 ● nd the range natural of a domain and 2 If function f : → , domain a f ( x ) nd and = 2x the range + natural of : 3 b f ( x ) = x 2 1 c f ( x ) = d f ( x ) = x x 2 2 e ● evaluate functions f ( x ) = 3 a Function F ● How ● What The function The function Example do is the you add function is is and subtract − 3. f (4) x Find: b f ( 1 ) c f (3 x ) functions? composition? equivalent to equivalent . to 1 function . given by: a b a = = 2 x 4 − operations and Write f ( x ) = Substitute = b 2 2 E2 Relationships f ( x ) and g( x ) and simplify. A LG E B R A ATL Exploration has domain has has Write each : two domain function a rule for functions. mapping Example a State b Write a f the has For so . {x : and the x ≠ 1}. state its domain. c domain Justify your 3x ≠ has function with a formed by adding mathematical or subtracting explanation or a , domains of f, g and and . h function 2 ⇒ and state its domain. . ≠ x 0, ≠ Exclude values of x that make the denominator Exclude values of x that make the radicand zero. domain h, has k ( x ) 2 a rule 2 the g, of d diagram. domain 3x For b 0}. . , h ≥ b Find g x domain a 2 {x domain has 1 1 1 3x ≥ 0, so 1 ≥ 3x ⇒ ≥ x negative. domain = ( g f )( x ) 2 = = k has − (2x + 1) Write with a common denominator. domain E2.1 Multiple doorways 23 For ( two f functions g)( x ) is Practice the f ( x ) and g ( x ), intersection of the the domain domains of of ( f f + ( x ) g)( x ) and and the domain of g ( x ). 1 2 h (a ) 1 = 2a + 1 and k ( a ) State the domains Find (h + k )( a ) 3 of and = h − ( a + 3). and state k its domain. 2 2 h( x ) = x − 5x 3 h( x ) = 2x and g ( x ) = 5 − x . Find ( g – h)( x ) and state its domain. 2 4 State the Find (h + h (c ) = Find 2c − x and domains k )( x ) k(x ) of and h state − 5 and k ( c ) (k h )( c ) = and 3x and its = + 1 . k. domain. 2 − 3c . state its domain. 1 5 g (x ) = 6x − 8, h ( x ) = and k ( x ) = x + 4 . Find ( g + h − k )( x ) and 2x (k − h − g )( x ) , and state 1 6 f ( x ) and g ( x ) = x a State b Write the domain down Problem of f and domain a function f b Write a function g c Write a function with composition mapping maps the Domain diagram elements of the of f + of with So the with is a domain {x shows A : domain {x way of B, : x : x x ≠ ≠ g 3}. ≠ 0 combining three onto sets and g A, B 0}. and ≠ 3}. functions. and maps x the C and two elements functions of B onto 1 1 2 4 3 3 9 13 f = {1, 2, 3} Range diagram, f maps 2 f (2) = 4 and g (4) = −3 f (1) = 1 and g (1) = 3 f (3) = 9 and g (9) = −13 24 of g. domain {x = From domain solving Write The f the 2 a Function domains. 1 = x 7 their onto of f = E2 Relationships and and {1, 4, 9} of Range of g = g then g maps 4 onto 3. {3, g C : 3 Domain 4, f 3, −13} B is the range of f C is the range of g A LG E B R A Applying gives a f to composite two elements from function A of of to f A C. and and The g. A then applying function that composite composite You From write the this domain The range of of ( x ) = g ( = f a f of as g o g o Example is function f g o f is ( x )) to function the A is to a elements C is of called B the combination of f (1) = 3 (2) = −3 g o f (3) = −13 the domain range means means from A to B , b List c Find d State is say f the g of ‘g of g : f of : {3, function f of {1, 2, 3, followed by g. g followed by f and f is a mapping diagram the elements of A, B for and the can also by function write g ( f g. ( x )) = g ( f (2)) = g (4) = −3 the domain and B to C. , composite . function . C and {1, You from , . range of . B C g = followed 3}. function and A A x ’. f 13}. f a a the 3 , Draw and g o is ( g ( x )) function a f and diagram, The b g maps functions. The g the mapping f 1 2 7 3 4 5 5 6 3 3, 5}, B = {2, 4, 6}, C = {3, 5, means g followed 7} c d Domain Range of of is is {1, {3, 3, 5, 5}. 7}. E2.1 Multiple doorways 25 by f Reect ATL and ● Explain ● For the belong ● If the why discuss it makes sense function to the range , domain of f 1 is the of to write explain ‘function why , f followed the 1 f f 2 is a (1) Draw b List c Find g o d State the For a entire b c domain The of f (1), g o composite the where mapping Find b State f h o f the 5 = 2x a Draw b State For two (a ) of g, what is the domain of ? g(f (x)) f function −2, g (9 ) from = 2, composite B to g (13) C. = 6 function g o f C f of (3) g o draw f a (x ) mapping diagram, range. 2, h (3) b , = the g o = 1, g ( −2 ) = a = (b ) here = 4, g (0 ) 5, h ( 4 ) = c , f = (c ) represents = 7, = 2, f h (2) (2) = d , g (d ) = 3, = −1, h ( 4 ) f (5) = x , g ( c ) = 4, = −3, h (1) f f domain and (8) and and g (h o range ( x ) = mapping range f the domain ● the range of f ● the range of g of x of − 5. diagram of functions the (7 ) = y , g (b ) two = 5 6 = z h f h ● 2 6 . must f 6 36 4.5 8 64 8 10 100 )(10 ) h o f (x ) solving the Determine = ( 6 ), h o + 3 a and range and is for function, diagram and Problem (x ) f B g g (5) and and g ( −5) h (1) A, (2) domain where , f domain where a f = 13 , elements functions 4 and the g f (3) B diagram o h , g o f to mapping state f A a each h o from ( 2 ) = 9, f a then 3 5, x, as: 2 function = of g’ g (x) Practice image by g o f and f is and is C number The to domain represent g o of f f is {0, 1, 3, 5}. ( x ). (x ). g : A = {1, 2, domain = of {7, 8, 3} of g is B = {4, 5, 6} 9} dierent E2 Relationships composite functions g o f . 12.5 A LG E B R A 2 The set functions of real f (x ) numbers. = 2x and g ( x ) Applying = x function − 1 both f and have then domain function g and to range input x ∈, value 3 the gives: 2 x f (x) = 2x g(x) = x − 1 2 2 3 f (3) = 6 and Applying function g (6) = function g o f 35 f × − or and then g o function g f (3) to = 1 35 input or value x gives f (x) g(x) g 2 2x 2 ATL f (x ) = (2 x ) Reect ● For ● Is the Example and 4 x = 35 composite 2x (2x) f (x) 2 − 1 4x − 1 − 1 discuss 2 functions equal and to ? , nd Explain. 4 . b a (3)) 2 − 1 = and a the f (x ): x g o g ( Find: c d Start with the inside function f. ⇒ b Start with the inside function g ⇒ c d g ( x ) goes in here. f ( x ) goes in here. E2.1 Multiple doorways 27 Practice 3 2 1 f (x ) a f e = g (x ) = x + 1 and h ( x ) ( g (3)) g ( f i 3x , f b (0 )) g (h ( f o h (x ) f j Problem ( g ( f x + 2 . Find: 2 )) ( f = c 4 )) f g ( x )) o h (2) h o h (0 ) k g o g (x ) d h o g ( h h( l h ( g ( x )) f ( 0.5) 1)) solving 2 2 A composite a a suitable b the f function function composite ( g ( x )) = 2( x − 5) + 1 and f (x ) = 2x A composite Find: g (x ) function g ( f ( x )) 1 1 3 + 1. function g( f ( x )) = , x ≠ ±1 and , g (x ) = x ≠ 1. Find: 2 x a a suitable b the function composite f and function f state o x 1 its domain and 1 range g (x ) 2 4 f (x ) = 7x − 2 and g ( f ( x )) = 3x − 70. Find g (33). In f g x 5 The graphs 7x show the functions f − 2 and = g. 33 g(33) Both y have domain 6 5 5 4 4 2 1 1 x 2 1 the graphs 3 of f 4 f o g (0 ) b e f o g (1) f sells a works of enough Explain to in Determine hours plus get what represent b 30 $500, x a f g, o f g o per 2% the g (x ) = 2 8 ≤ 6}. f x 0 6 2 1 3 4 5 6 evaluate: (2) c (5) g o g week at a travel commission on f f (3) ( g ( f agency. sales d 4 x + 4 f g (4 ) She over is paid $5000. a One weekly week she the functions f ( x ) = 0.02x and g ( x ) = x 5000 context. whether and g o ( 4 ))) f o g ( x ) or g o f ( x ) represents her commission. 2 7 x commission. and this 5 and a salary ≤ g(x) 2 0 Emily 0 3 f(x) 6 : y 6 3 Using {x (x ) = x − 64. E2 Relationships Find x such that f o g (x ) = 0 4, rst nd x A LG E B R A Modelling using compositions of functions C ● How Objective i. identify In of D: 2, a diver increases This t you need in real-life authentic to identify to real-world situations? contexts real-life the model situations meaning of the given functions in light Let (0) Let deeper the into pressure the diver’s on Depth d 40 32 60 44 80 65 100 80 120 90 d = below, pressure pressure is (atm) be 0 be Explain 3 Use the 4 Explain the and the f what tables to to at mass body dierent of water above the times. pressure in exerted atmospheres on a diver (atm), at where dierent 1 atm is 30 40 50 60 70 80 90 1 2 3 4 5 6 7 8 9 10 connecting nd nd Find f 7 g time (60). connecting = the level. 20 15. diver increases. 10 = g (60) the diver’s 0 function how sea function (20) the measured at (meters) p shows ocean, the (meters) 15 table, the depth 20 f (t) g 2 0 Pressure 2 of 0 The Depth so shows atmospheric f composition mathematics will (seconds) next depths. 1 function elements descends and table Time The use problem. Exploration As you Applying relevant Exploration the can t and Explain the depth d depth what and f d (60) means. pressure p. means. o the f (120). time Explain before the what diver g is o at f (120) a means. pressure of 9 atm. E2.1 Multiple doorways 2 9 Practice 4 Problem 1 The price solving p of an orange, in cents, is a function f of its weight w, in grams. Oranges are domesticated Weight so w 100 125 150 200 250 300 350 400 you are unlikely nd them to (grams) Price p naturally 12 15 20 26 33 36 45 50 (cents) The weight Radius w of an orange, in grams, is a function g of its radius r, in cm. r 3.8 4.2 4.3 4.8 5.1 5.3 190 210 215 240 250 265 (cm) Weight w (grams) a Find f (125) b Find g (4.2) c Evaluate d Determine between 2 A f as a increases and o (350). g (5.3). and in a explain function radius of computer dot at f g (5.1) the the particular starts and the composition an orange screen middle constant what and saver of the The to a screen expand Copy is to and Time t c The radius nd the The area Hence 3 0 r is A of f with top this given the simulates and in an the relationship cents. expanding expands circle. outward a and height table for 0 1 0 2.5 by the of bottom the 20 of cm. the = The its The circle takes 4 seconds screen. radius 2 of the circle 3 at time t seconds: 4 10 function f (t). Use the values in your table (t). circle the circle radius 4 is a function g (r) of the radius r. Write g (r). express so cm t (cm) function function d the complete r describes price 0 rectangle touch means. rate. (seconds) Radius b a = that its screen 20 t this area A of the E2 Relationships circle as a function of time t. the to growing in the wild. A LG E B R A 3 3 A cylindrical container has a radius of 50 cm and a capacity of 500 cm . 3 It is being lled with water at a constant 50 rate of 10 Write t b Write c Find d Determine A of a a function for the second. volume v (t) of cm water in the container after seconds. to 4 down per cm h a cm down h o v (t ) reach pebble the a for the explain long it height what takes it for h of water in the container in terms of v means. the height of the water in the container cm. thrown water Write and how 50 is formula ripple down into still water increases the radius the area r at in and the rate terms of creates of 2 a cm time t circular per after ripple. The radius r second. the pebble was thrown. 2 b A (r) the c 5 = is meaning Find For πr the each area pair a write b describe of a A of down A o r of of the water f meaning possible water ripple in terms of its real ripple and of life g g in o after the 60 Fuel consuption vehicle ii Height table below: f use for the composite function. iii of Radius of iv is a function of water of of in a tank is a time. a Sum of Bank time. is of circle is of angles a a function of a function sides savings is cost Volume is a function of fuel a of regular of the the polygon. function of of a Size tank is a function is a function of the radius circle. of each polygon of the height. Volume of the number Fuel consumption. time. polygon v g velocity. function Explain seconds. f i radius. (t ) . functions the the the is a angle angles Interest amount of earned of of a function the is a regular of the sum polygon. function of savings. E2.1 Multiple doorways 31 You can graph composite functions on any GDC or graphics software. For 2 example, for functions f ( x ) = x + 2x + 1 and f 1 functions f ( x ) = f 3 ( f 1 ( x ) = 3x + 5, the two composite 2 ( x )) and f 2 ( x ) = f 4 ( f 2 1.1 ( x )) are shown in the graphs below. 1 1.1 y 2 f (x) = x + 2x + y 1 1 8 8 2 f (x) = 3(x = (3x + 2x + 1) + 5 + 2(3x + 4 6 6 4 4 2 2 2 f (x) + 5) 5) + 1 3 f (x) = 3x + 5 2 0 0 4 4 ● Does a Exploration 1 Find two 2 Expand composite functions function f and g such simplify functions when Find functions two 4 have a unique decomposition? 3 functions and x 2 2 4 Decomposing D 3 x 2 2 the and composite h that and k their explain function such composition that is how you is: might nd the simplied. their composition is: The has word composition meanings photography, 4 Simplify , and nd functions h and k. Are the functions the same literature, as you found in step 3? music, Explain. chemistry, 5 Determine its whether decomposition. or not it is better to simplify a function before nding Explain. ower design, course Does and every Practice composite each function 3 function have a unique solving question, h( x ) = f o nd two functions f and h( x ) = (2 x − 1) g whose composition is the g (x ). 3 1 decomposition? 5 Problem For discuss 3 2 h( x ) = 2x − 1 3 h( x ) = 6x 3 4 h( x ) = 6 32 x − 5 5 h( x ) E2 Relationships = 3x 2x − 1 6 h( x ) = 2 − 5 2 cooking, arranging, metallurgy, printing, Reect in art, and of mathematics. A LG E B R A Reect ● and Compare Did ● you Write and discuss your all answers nd down a the to same non-linear decompose function 4 means the in Practice function function. the 5 functions with g and that Explain context of the others f in your class. ? models what a the real life situation, decomposition of the problem. Summary The function is the same The as f The function is the same followed You as g For ( f two + functions g)( x ) and the f ( x ) and domain g ( x ), of ( f of f the domain g)( x ) is composite of of can f Mixed of the domains ( x ) and ( x g is the function g g ( f ( x )), and say = g ( f ( x )) means f followed by g = f ( g ( x )) means g followed by f practice = 2 − 5 x , g ) or and g ( x ). 2 Problem 2 f function f the x 1 of x.’ ( x ) intersection the write of ( x ) by function x ( = ) x − 4 x, h ( x ) = and solving 4 x 6 2 k ( x = − ) , x If f (x ) = 3x + k and 4 g (x ) = , ≠ 0. nd the value 3 x of Write down these functions in simplest k such and a ( f + g )( x ) b ( g f )( x ) c ( f that the composite functions f o g form: g o f are equal. + h )( x ) 2 7 d ( g g ( h )( x ) e (h + k )( x ) f (k If f + State Find the f 2x − 3 and g (x ) = , 2x nd: f ( g (x 1)) g ( b f ( 3 x )) k )( x ) 8 2 = h )( x ) a f (x ) o domains of functions g ( x ) and g o f ( x ), f and and g state If f (x ) = x − 1 and g (x ) = 4 x + 3, nd 2 below. g ( f (3 x 1)) their 9 The notation [x] means the greatest integer domains. not a f (x ) = x + 1, g (x ) = 2x exceeding the value of x. If f (x ) = [ x ], 8 − 1 g (x ) = 15 x , and h( x ) = , nd: x 2 b f (x ) = x , g ( x ) = x − 1 a f c f (x ) = x + x, g (x ) = Given the functions p (t ) = 4t + 1, q (t ) = t − 4 r (t ) = , t ≠ 0, nd these functions and The a the b number certain q ( r ( t )) c p (r (t )) d 1 Given the functions f (x ) of < 15, food B and g (x ) = 2x f, g bacteria is (T ) T is taken = B in can 20T in out temperature function T (t ) , = 5)) c h( (π )) f food be refrigerated modelled − 80T degrees of the + 500 , by Celsius. where When refrigerator, the r (q (t )) food 4 (h ( temperature function 1 < T domains: p (q (t )) f 2 the a b 2 state t their 10 at 1 and 1 2 − 3x 2 3 g 2 = 4t T can + 2, 0 be ≤ t modelled ≤ 4, by where the t is the + 4 x time in hours. 2 and h( x ) = x − 2, nd in terms of and h the a Find the composite function B oT (t ) and functions: explain 2 a what it means in the context of the 2 + 4 b 4 x + 16 x + 14 problem. x x 5 Given that f 2 (x ) = b and g (x ) = 2x 3 a g ( f ( a )) b f ( g ( + 1 Determine how count 5000. long it takes for the bacteria nd: to be b )) E2.1 Multiple doorways 3 3 11 A store to If owner decide items the do adds 50% selling not sell to price in 4 the of wholesale items weeks, he in the sells price ii write store. them 20% Write down selling price wholesale a s function of price an that item in represents terms of the write for Write down discounted selling c Write its down d a function price d of that an represents item in terms the of down the a the composite discounted the From function an price online discount price in terms of b You for see price was that a 25% sale function that your of an item sale. a x much you then you rst would use apply the the 25% a composite the how of represents sale shoes and if then function much you use you rst the would apply You store go favorite the the discount nd a pair the of shoes price two composite a and of you the like shoes functions you for $50. using iii iv, and state the the found in dierence in price you receive online to shoe store a spend is them. For each question, nd two functions f it, having g whose composition is the function a = f o g (x ) 5 4 If pay discount whose h( x ) 25% if $72. shopping coupon. that and sale Evaluate and and of coupon. to 13 $5 eect composite how shoes down between 12 a represents pay price. discount wholesale write that 25% wholesale Find the coupon price. represent the cost w iv b g (x ) function discount. represents a a the at iii a down represents original cost of a a h( x ) = −(x + 1) c h( x ) = −5 x + 7 b h( x ) = d h( x ) = 4 − 3x pair shoes: 3 2 i write down represents a f function the cost eect (x ) of x using your Review 1 An oil in spill meters. At 4 x e discount − 8 that h( x ) = 10 coupon context is modelled time t = 0 as the a circle radius is of 70 radius m. r 3 The The speed hours, of can a be car, v (in modelled km/h) using at the a time t function 2 radius increases at a rate of 0.8 meters per v (t ) minute. r a Express b Find the radius r as a function of (in = 40 + 3t + t liters/km) . at The a rate speed of of fuel v consumption, km/h can be time. 2 v modelled A(r) the is composite the area of a function circle of A o r (t ) what it radius Determine function r (v ) = + 0.2 0.1 500 r. Write down the function r (v (t )) , the rate of means. fuel c the a Explain by where how long it takes for the area consumption as a function of time. of b Find the rate of fuel consumption for a trip 2 the oil spill to exceed 100 000 m that 2 The formula K (C ) = C + 273 converts 4 temperature into Kelvin temperature. lasts 4 hours. Celsius Composite functions can also be used to create The and/or explain number puzzles. Ask a friend 5 formula C (F) = (F − 32 ) converts to Fahrenheit think of any number, then: 9 temperature a Write into down convert a Celsius composite Fahrenheit ● multiply ● divide temperature. function temperature into a Kelvin Write boiling composite and freezing temperatures are 212° and 32° in the boiling and freezing and and then then add add 6 3. the the steps function steps are as that functions, shows the and the order in executed. Simplify the Make can E2 Relationships your function, friend’s and explain how to number. temperatures 5 Kelvin. 34 2 4 respectively. nd Find by by in b Fahrenheit result down which The the number to temperature. b the up solve your own using number composite puzzles which functions. you Doing E2.2 Global and context: Objectives ● undoing Scientic Inquiry Understanding onto and one-to-one functions and technical innovation questions ● What ● How are onto and one-to-one functions? F ● Finding the a function algebraically do you nd the inverse of a ● Restricting the necessary, Justifying each inverse the so a domain that that of its two function of a graphically function, inverse functions is also are a ● if function inverses C are ● of that Is do you inverses the know of inverse when each of a two functions other? function always a function? other Justifying How a function is self-inverse ● Are ● Can there functions that are self-inverses? D ATL Test everything be undone? Critical-thinking generalizations and conclusions 3 5 SPIHSNOITA LER Finding ● of function? ● ● inverse Y ou ● should decide whether diagram pairs already or a set represents a mapping of a know 1 ordered function how to: Decide which If function, state a it does reason a a why. B f p b q c r g A B a p b q c r h M = it a x b y c z {1, each a represents represent a c If not the A b 2 diagram function. 3, 4}. relation is R 2, not = a {(2, Determine is a function function, 3), (1, whether 4), state (2, 1), from the (3, M or to M. reason 2), (4, not why. 4)} 1 b R = {(2, 1), (3, 4), (1, 4), (4, 4)} 2 ● use to the ver tical decide if a line test relation is 3 a Use the each ver tical relation line here is test a to determine if function. function y y a b x x ● form the composition of 4 For the functions f ( x ) = 2x + 1 and 2 two functions 3 6 E2 Relationships g ( x ) = a g( x ) f x + 1, nd: b g f ( x ) A LG E B R A Types F For a must ● What ● How relation map For a to of are do functions onto you between one and function f : nd two only A → the inverse to be a element functions? of a function? function, in the element in the ● Each element in A domain can ordered have pairs A must only (a, b ) have an one image and (a, b 1 Onto This each element from the domain range. B : Each two one-to-one sets one ● contains and image in ), B. in So then b 2 the if = a range B function b 1 2 functions mapping diagram shows a function A f : A → B B f a p b q The is Each element The element f → : A A B is in not function element in s in f : the B, an A c r d s domain A however, onto → B maps is not to the one, and image of any only any one, element element in A. in element not the s in image element in B of A B Therefore, function. is onto if every element in B is an image of an A 1 In this graph of y = − 1) , (x if you draw horizontal lines through every 1 possible y y 2 = (x − 1) 2 2 y-value in the then range these lines ( y-values) will is all the intersect image of the an graph element line, in because the every domain element (x-values). 1 0 1 3 1 The only horizontal if its Reect ● Do ● Draw the all line graph and graphs three domain test for intersects discuss of straight dierent and onto any of a line function drawn on f is it onto, at least if and once. 1 lines graphs range functions: horizontal represent that the onto represent functions? onto Explain. functions, and specify functions. E2.2 Doing and undoing 37 4 5 x f(x) 2 Top As right x the can set is the graph assume of real numbers, any of value, numbers. hence this the function the The (x ) : domain range function f is is not of the x , the set of f : → function . is non-negative real onto. x f(x) 2 If, however, then f ( x ) passes is the we an dene onto f (x ) = function, horizontal line + x such and that the f graph : → for ∪ {0}, these y-values test. x One -to-one This mapping function and f is Y a A is = f : X {A, diagram → B, Y, C, one-to-one function the f image function f is : X functions X = shows {1, 2, Y f the 3, 1 D 2 B 3 C 4 A 4} D}. function. A of → B is a exactly one-to-one one one-to-one if element f (a ) = f function in (a 1 the ) if every domain. implies element In that a 2 other = in the words, range a a 1 2 1 Looking again at the graph of y 1 = (x − 1) , every y-value is the image of y y = (x − 1) 2 2 2 exactly line one x-value, through once every so y is a possible one-to-one y-value, function. these lines If will you all draw a intersect horizontal the graph line 1 only. 0 1 1 The if horizontal and one only its line test graph for one-to-one intersects any functions: horizontal a line function drawn f on is it one-to-one, at exactly point. Reect ● if How and does discuss the horizontal 2 horizontal line test for line test one-to-one for ● Is every ● Is a ● Draw ● How can a function be onto ● How can a function be one-to-one ● Can straight quadratic 3 8 a three line a one-to-one function dierent function be neither that but onto E2 Relationships functions function? one-to-one? graphs onto dier from the functions? Explain. represent not nor Explain. one-to-one functions. one-to-one? but not onto? one-to-one? Explain. 3 4 5 x A LG E B R A Example Determine 1 which of these functions are onto, one-to-one, both, y y a or neither. y b c x 0 0 x 0 x y a 0 x Use Horizontal is onto. lines Some function is intersect horizontal not the graph lines in at intersect least at one more point, than so one the point, the horizontal line tests. function so the one-to-one. y b 0 x Some onto. so horizontal Horizontal the function is lines lines do do not not intersect intersect the the graph, graph so in the function more than is one not point, one-to-one. y c 0 The not range x is the one-to-one set of since non-positive horizontal real lines numbers, intersect at hence more it is than onto. one It is point. E2.2 Doing and undoing 3 9 Practice 1 1 Determine a f : → which of these functions are onto, one-to-one, b f : neither A → B ; or A both. = {x : 5 ≤ x < 5}, B = {y : 3 y y 5 4 4 3 3 2 2 1 1 x 0 5 0 5 c f : 4 {x 3 : - 2 2 1 1 ≤ x 4 3 2 1 1 2 3 4 5 3 4 5 6 1 2 2 3 ≤ 2 x 8} → {y : - 1 ≤ y ≤ 1} d f : → y y 1 6 4 0.5 2 x 0 5 4 2 1 1 2 3 4 1 2 3 4 5 2 x 0 2 4 1 e f : → f f : → { y : y ≥ −3} y y 5 4 4 3 3 2 2 1 1 x 0 5 4 3 2 1 1 x 0 5 3 2 1 1 1 2 3 3 4 4 4 0 E2 Relationships 6 ≤ y < 4} A LG E B R A f g : → h f : {x : x ∈ , −3 y ≤ x ≤ 5} → y 20 5 4 10 3 2 1 x 0 3 1 2 1 x 0 4 3 2 1 1 10 2 3 4 5 6 1 2 20 3 4 5 Problem 2 Create your a onto, c neither If you them, a but a own not onto change you relation also solving the a A set friend gives ● From ● Turn ● At ● My of of inverse ordered the ordered pairs in a one-to-one, d both relation and R reversing by . every relation has an not onto relation pairs, but inverse onto one-to-one. Since which is State you right the 4th house on instructions go the 5th a ● Start ● Add ● Divide ● Subtract ● The worked function a real turn one get route to on get left the on to her B21 house: for 3 km. back home out. f models that domain number Georgia Avenue. right. them possible with on to Drive. light, directions largest north Kanuga trac you down its these home, is the how Write 1 your down Explain a the b relation. Write 2 are: one-to-one elements obtain is that one-to-one nor Exploration 1 functions and the from steps your in the friend’s house. algorithm below. Continued next range. x. 4. the 5 nal result from by this answer is 3. result. y on page E2.2 Doing and undoing 41 b c Write down the Write down a Look from algebraically. f to a g g, i your and whether one-to-one state f and its g that that models functions interchanging function, State at algorithm g algorithm. Rewrite d inverse function the x f and largest starts the and y, so possible with steps g. in y Explain that g : x domain and this how → y. and leads to x. inverse you Justify can get that g is range. are: functions ii onto functions. Simplify the functions e Draw the graphs of f ( x ) and g ( x ) on the same set of axes. Write graphing the Step 2 of inverse equation of Exploration of a function: interchange the x the 1 line goes y the them. symmetry. through reverse and of before down the process algebraic by process making x the of nding subject, the then variables. 1 The notation Inverse 1 The The the 3 If the inverse of a function f is f functions : inverse domain 2 for graph a function range of original the of and the of in relation is f : A → B function inverse function inverse the of the a the a y = relation formed when the interchanged. function line also is are is the reection of the graph of x function, then it is the inverse function of 1 the original Example Find the function, f : B → A. We say that the function is invertible 2 inverse of the function . Write 5y = 6x 6x = 5y the function using 5 + 5 y instead Make = 5( y + x the 1) Write can 4 2 also f ( x ). subject. Interchange You of interchange the x and E2 Relationships y variables rst and then isolate y in inverse x and y. notation. A LG E B R A Reect ATL ● Are ● Is all the and discuss linear relations inverse Example the of any 3 also linear linear functions? function also a Explain. function? Explain. 3 a Find inverse b Conrm c Determine your if of the answer the function to a inverse , algebraically. graphically. is also a function. a ( y 3)(x 2) = 1 State the excluded Interchange x value. and y y b 6 y = x 5 4 1 y = + x 3 − Graph 2 the function and its inverse. 3 Add in the graph of the line y = x 1 2 y = + x − to 3 check that one graph is a 2 reection 1 of the other in y = x. x 1 2 is the line y = the is Practice 1 Write is a f = b g ( x ) c h ( x ) ( x ) = = because it is a reection in a function because it passes the vertical line test. 2 down inverse of x c ATL inverse the also {(3, {(2, {(0, a inverse of each function, and state whether or not the function. 1), 4), 0), ( ( ( 1, 5, 2, 1), 3), 4), ( ( ( 3, 2, 1, 1), (1, 3), 4), 1)} (1, (2, 1), 2), ( ( 4, 3, 4), 3), ( ( 1, 4, 2), 4), (3, (1, 1)} 1)} E2.2 Doing and undoing 4 3 Problem 2 Copy each Determine a solving graph if the and draw graph of the the inverse inverse on of the each same set function of axes. also Use represents line function. the vertical test. y y a y b c 3 8 2 6 1 4 4 3 2 1 2 x 0 3 2 2 3 4 5 6 x 0 x 0 2 2 2 2 3 4 4 6 8 5 4 2 2 1 1 10 3 1 2 3 4 y y d y e f 5 1 4 4 3 x 0 1 3 1 1 2 2 1 2 1 3 x 0 x 0 4 3 2 1 1 2 3 4 4 3 2 1 1 4 1 5 2 6 3 1 2 3 4 5 3 Find the the inverse function is of also each a function algebraically. Determine if the y = - 4 x + 1 y b = 4 − − x x c y = −1 − 2 x ≠ 0 y e = C = x ≠ −5 f y = x h Reversible ● How ● Is the do you know inverse Exploration and of a y = x + 2, x ≥ −2 irreversible when two function x + 1 + 5 3 3 y , x x g 3 1 1 y − 5 = 2 d of function. 3 a inverse functions always a i y x + 3 x 2 = , x ≠ 2 changes are inverses of each other? function? 2 2 1 Draw the graph of the quadratic function y = x . State the largest possible 2 domain 2 Find and the the inverse corresponding of the range function of the function y = x algebraically. Continued 4 4 E2 Relationships on next page 2 3 A LG E B R A 3 Draw that the your inverse graph on the shows 4 Determine if the 5 Determine how same the inverse graph. inverse of the of Draw the function the line y = x and conrm function. is also a function. y = 2 also 6 a State the of Reect Is can restrict the domain of x so that its inverse is function. range ● you domain its and there and inverse range discuss more of your new function and the domain and function. than one 4 way of restricting the domain of the function 2 y = x so that its inverse is also a function? 2 ● Is ● When the function y = x one-to-one and onto? 2 you function, If the does inverse domain of restrict of the a it the domain become function function so of y = one-to-one is not that a its x so and its inverse is also a onto? function, inverse that is you a may be able to restrict the function. The proof of this Theorem The inverse and a of a function one-to-one Example f is also a function, if and only if f is both an onto theorem is the of level beyond this course. function. 4 2 a Find b If the the its inverse inverse inverse is is of not also a y a = x 1 algebraically, function, function, restrict and the conrm and conrm domain of graphically. the function so that graphically. 2 a y = x 1 Find the inverse. y 2 f (x) = x − 1 1 f (x) = √ x +1 2 Graph both functions 2 is the reection of y = x 1 and in the line y = conrm that one is x x a y = x reection in f (x) = −√ x the line of the other y = x. +1 3 Continued on next page E2.2 Doing and undoing 4 5 b 6 Tr y 5 dividing function the into original pieces that are 4 y = x both one -to-one and onto. 3 2 1 f (x) = √ x + 1 2 x 1 2 2 3 4 5 Dene the restricted 6 1 domain for each section. 2 f (x) = x − 1, x ≥ 0 1 2 Restricted domain x ≥ 0 y 6 y = x 5 4 2 f (x) = x − 1, x ≤ 0 1 3 Write 2 the function inverse using notation. 1 x 0 3 2 1 1 2 3 4 5 6 1 f (x) = − √ x + 1 2 2 3 Restricted Therefore, For the for domain the domain Example x x ≤ 0 domain ≤ 0 of x ≥ 0 of f , . f , . 5 2 a Find the inverse b Restrict the domain and of f ( x ) domain of = f x so 6x that + its 2 algebraically, inverse is also and a conrm function, graphically. and state its range. 1 c State the d Conrm domain and graphically range that of the f inverse function is indeed a function. 2 a y = 6x x + 2 You cannot immediately isolate x 2 x 6x = y 2 = y 2 = y 2 x 6x + 9 + 9 Complete ( You the could square also use to the solve for x quadratic 2 (x 3) + 7 formula to solve for x.) Interchange Continued 4 6 E2 Relationships on next page x and y A LG E B R A Since they one are graph is inverses the of reection each of the other in the line y = x, other. y 8 y = 3 ± √ x + 7 6 4 2 Draw and the the graphs line y = x. x 8 6 4 2 0 2 4 6 8 2 4 y = x 6 2 y = x 6x + 2 8 Identify b The vertex is (3, 7). Therefore and the inverse domain c The of to f be is domain a function, either of f is x x ≥ ≥ 3 the domain that would make the function onto for one -to-one by nding the ver tex of the formula the parabola the or x ≤ either 3. graphically, or using . 3. 1 Then the domain of is f x ≥ - 1 and the range of f is y ≥ 3. Select y is a a domain function, such and that graph the inverse it. 8 d y = 3 + √ x + 7 6 4 2 x 8 6 4 2 0 2 4 6 8 2 Check y = that the symmetrical 4 graphs about are the line y = x x 6 2 y = x 6x + 2, x ≥ 3 8 The ATL graphs Practice For each a Find b If inverse inverse that its restricted reections of each other in y = x. 3 function its the so are is in questions 1 algebraically, not inverse is a to and function, also a 8: conrm restrict function the and graphically. domain write the of the inverse original f ( x ) = with its domain. 1 1 function function 5x 2 2 f (x ) = 7 − 2 x 3 f ( x ) = x 6 f ( x ) = (x 3 2 x 2 4 f ( x ) = 1 5 x f + 1 (x ) = 2 , x ≠ 0 2) x 2 7 f ( x ) = x 2 + 2x 4 8 f ( x ) = 2x 4x + 5 E2.2 Doing and undoing 4 7 Problem 9 Below is the and of left set is of zero. the solving the real graph Reecting inverse, of the numbers. the below absolute The range graph of f value is ( x ) the = function set |x of in the line 3 3 2 2 1 1 x 1 Explain Write apply Apply 10 In A you Applying you have like players of handicap you on bowler’s In a one or very golf, while win, 180 Write b Find down the in to to 175. f so real-life The domain gives this graph a| = a a| = -a for a that A a inverse to of h (s) determine the ‘perfect’ score of strikes all ten an optimal The 9 in of than degrees will game pins rest rather 5 the and ball 8 a in if inverse often in solving have a score a 170 Handicaps if and are to reach question a function. allow you her usually a solution 10 ‘handicap’ to example, bowls is (h). comparisons bowl a 150 handicap calculated is and 5, based (s). of = are calculated 0.9(220 h (s). and the row, the pins the from ball. using: s) Explain conrm inverse upright. the So, a for an why your also a it needs to be restricted. result graphically. Use bowling, a strike itself hits pin will perfect with just 1, when just will 5 by game 48 pins. E2 Relationships other if 9 with can bowl pins. it pins, tilts bowler’s and connect by down you four fall handicap getting knocking down 3, whose achieved by right-handed number ball is However, any A is only be a your is never function. opponent bowling done knocked and bowler’s pins. ball are ball, with be where the connecting 4 8 can one strike, score ten-pin This with connect left-handed 2, average 300. 12 0. contexts player’s For its less Find 0. < domain. handicap c > a 3 In the graph a for x successfully functions levels. handicaps domain of restricted strategies Davinia score league, your players added h (s) a domain with inverse dierent 30, average bowling about number would f mathematics learned is the for mathematical bowling is restrict function selected then a could inverse sports . numbers 2 3 D: x 2 3 handicap your 3 2 the = |x 0 3 2 what with 2 1 how Objective iii. 1 1 the y = real y 0 2 ( x ) right. y 3 f positive pins, just the just ball and the a 1, result of is 15. than zero. A LG E B R A This mapping diagram shows a function and its inverse. A B f x f (x) 1 f 1 f maps x onto f ( x ) and then f maps f ( x ) to x. 1 So the composite function f 1 f (x ) = x. Similarly f f (x ) = x 1 If two functions and a and f are inverses the given of each other, then . Example Conrm f 6 algebraically that functions are inverses: and b and a 1 and , so f and f are inverse functions. Find and simplify. Find and simplify. Check that functions b both are Find Find Check Since , the functions are mutual that composite equal to x and simplify. and simplify. both composite inverses. functions are E2.2 Doing and undoing equal to x 4 9 Practice In 4 questions functions 1 are to 8, determine inverses of each algebraically whether or not the pairs of other. 1 1 f ( x ) = x 3 ; g ( x ) = x + 3 2 f ( x ) = 4x + 8 ; g ( x ) = x 2 4 2 3 f ( x ) = - 5 x 2 ; g ( x ) = -5 - x 5 2 2 4 f (x ) 5 f (x ) = = x −4 + 2 + − 2, x ≥ − 2 ; g (x ) = (x 4 x − 2) − 2 2 , x ≥ 0 ; 2, x ≠ 2 g (x ) = (x + 2) , x ≥ −2 2 1 6 f 5 + (x ) = − x 7 f ; 1 x 1 + x (x ) = , x Problem ≠ −1 ; 2x g (x ) = 2 1 x 1 + x g (x ) = , x ≠ −2 2 + x , ≠ −1 x solving − x − 2 2 8 f ( x ) = −2 x − 2 ; g (x ) = 2 Exploration In Practice inverses 4, question when, 1 Graph 2 State, 3 State the 3 in fact, functions therefore, what whether For the or not two f functions 2 students think that f and g are mutual not. state why dierence is the between information functions this are case. and must be mutual given in when this example. determining inverses. f ( x ) = 3x 1 and g ( x ) = 2x + 3, nd: 1 ( x ) and 1 d are 4 1 a the many and additional Exploration 1 8, they g 1 ( x ) b f e g 1 f Repeat g g ( x ) 1 ( x ) step 1 for these c [ f g ( x )] 1 f ( x ) functions: 2 a 3 f ( x ) Make = a Reect 2x + 5 ; g ( x ) conjecture and b = about the discuss f ( x ) = relationship x + x 1 ; g ( x ) between = x + and 1 . You 6 should discovered Which is easier, nding or proof is any two functions f and g, E2 Relationships of this beyond 4.The result the level . of 5 0 in ? Exploration For have this this course. A LG E B R A D When the doing same ● Are ● Can there and undoing produces result functions everything be that are self-inverses? undone? 1 The inverse You can of say the that function f is f ( x ) = 2 x is ( x ) = f ( x ) = 2 x, so f is its own inverse. self-inverse. 1 A function f is self-inverse Exploration 1 Determine function 2 3 the the other 4 is 1 k ∈ , for = not which f not x, , is k ∈ , whether is or not any linear self-inverse. self-inverse. Are there values of k for self-inverse? x , is f ( x ). graphically k ≠ ( x ) if ( x ) and ( x ) if Determine f f , function than which form if Determine f 5 algebraically of Determine which if x 1, is ≠ is self-inverse. not 1 is Are there values for there values of k self-inverse? self-inverse. Are k for self-inverse? Summary For a function f : A → 1 B: The inverse relation ● each element in the domain A must have in the range each element in function the domain A can have image in the The range is function an A image function f : A of f : → an A B is onto element → B : A → B domain is the and are range is a if in every element in graph of of the the inverse graph of of a the function original is the function 3 A one-to-one function the line y = x. B If the inverse relation is the inverse function is also of the a function, original then 1 one element element The A in in the the horizontal function intersects least f is any range is the image of if The and horizontal only line if its drawn if graph on it inverse andonly at function at If f is one-to-one, intersects exactly one any if and horizontal only line if the may so inverse be that able its say the function is invertible of if f a is function both an f is also onto a and function a one-to-one two of to functions then f and f are inverses and = of each x. its drawn on it For any two functions f and g, point. A If We 1 once. graph A. function. other, A → Theorem tests: onto, B exactly domain. line : a function restrict inverse is the also a is not a domain function, of the function f is self-inverse if . you function function. E2.2 Doing and undoing it function, if f every of interchanged. B. in A f the only reection one function when B 2 ● a an the image of formed 51 Mixed 1 i practice Determine if these relations are functions. 3 Justify that ii Find the inverse iii Determine if of the the which are also of these functions have inverses functions. relation. inverse is a function. a f : → y a R = {(1, 2), (2, 3), (3, 4), (4, 5)} 6 b S c T = {( 2, 0), (3, 1), ( 5, 1), (6, 7), (0, 0)} 5 = {(0, 1), (3, 1), ( 4, 1), ( 3, 6), (3, 1)} 4 2 Determine onto, whether neither, or each function is one-to-one, 3 both. 2 1 a f : → x 0 y 3 2 1 1 2 3 1 5 2 4 3 3 2 b f : {x : x ≥ 1} → { y : y ≥ 1} 1 y 5 4 3 2 1 1 6 x 0 2 3 4 5 1 5 2 4 3 3 2 b f : → 1 y x 0 5 1 2 3 4 5 6 7 8 9 10 4 c 3 f : → 2 y 5 1 4 x 0 7 6 5 4 3 2 1 1 2 3 1 3 2 2 3 1 4 x 0 c f : → 6 5 3 4 2 1 1 2 1 2 y 4 3 3 4 2 d 1 f : → [ y : y ≥ −1} y x 0 3 2 1 1 2 3 5 1 2 4 3 3 4 2 1 x 0 3 2 1 1 1 2 5 2 E2 Relationships 2 3 4 5 6 7 8 A LG E B R A 4 a For each function below, nd its 2 inverse algebraically, and conrm (x 4 d f (x ) = 2 + 3x − 4, x ≥ graphically. − 2) + 4 g (x ) = ; 3 3 3 4 x + 13 2 b If its inverse is not a function, restrict e the f (x ) = x + 3x − 1, x ≤ − ; g (x ) = − − 2 domain of the original function so that its 7 inverse is also a function, and write down The weight function with its restricted w in kg of a certain type of sh is the related inverse 3 2 to its length l in cm, and domain. can 6 by the function w = (9.4 × 10 be modelled 3 ) × l . 3 i f ( x ) = -3x + 8 ii f (x ) = x By −1 obtaining the inverse of the model, determine 4 the 2 iii f ( x ) = 4 f of a sh that weighs 0.58 kg. 2 x iv x v length f ( x ) = 3x 2 1 (x ) = , 2x x Objective ≠ 1 D: Applying mathematics in real-life 2 contexts 5 Find the inverse Determine function is of each whether also a or function not the function. If algebraically. inverse the of inverse iii. the not a function, restrict the domain of a f ( x ) so = that its inverse 5x is b f also ( x ) a = correctly 2 f 1 (x ) = x 6x x − d 3 + mathematical a strategies solution answer function is the best questions, to use, the you will original have or the to decide inverse. 8 2 A computer = 700 company 12t to uses nd the the formula depreciated value in 2 g (x ) = +1 2 reach function. d (t) c selected to the which function the relation To is apply successfully d dollars of computers t months after they are 5 put on sale. 1 2 e h( x ) = x − 3 p( x ) = f + 2, x ≠ 0 x x g + Calculate b Find Justify and state what this means. , x ≠ 3 s(x ) h = x + 3 , x ≥ -3 t such that d (t) = 50, and explain what 3 this 6 d (24) 2 q (x ) = x a algebraically that these pairs of value means. functions 1 c are inverses of each Write the 1 a f ( x ) = −7 x + 4 ; g (x ) = − (x ) = + 3, x x for (t), d ≠ 1 ; formula means in this and explain what context. + d 7 2 f formula 4 x 7 b a other. x 5 x 3 g (x ) = 1 Find be , x after worth how many months a computer will $500. ≠ 3 1 3 −3 + c f e 3 2x (2 x (x ) = , x ≥ 0 ; Find what 2 Review 1 in Aryabhata, came up ● The ● is a 6th century this added result That ● Then Hindu mathematician, 3 puzzle: ● The ● Find to is result 8 Ask is a certain divided is the with by Choose by 2, a is by from that result. given 34, write arrive subtract 12, the at Invert the think of a following explain positive integer. operations in order number: Square ● Multiply the result ● Add the result. ● Ask the function, down the add and result to the ● the original steps, the number. by 2. 3 to for the nal result. in 6, multiply nally you process process then the above write its number in the inverse that your form so of that a you classmate can started order, with. Find the original number. State for number. the divide by result numbers this puzzle would have no result is solution. 2. Make up your own puzzle whose the obtain. same b and 34. number. number, Justify 100, 6. 4 a = 2. which 2 (t) means. classmate the out to this perform identify necessary d number. multiplied subtracted answer a Then Write Starting that context on 5 such 2 with ● t + 3) g (x ) = and justify the as the number you start with. result. E2.2 Doing and undoing 53 How can we get there? E3.1 Global context: Objectives Describing Scientic Inquiry translations using vectors and technical innovation questions What How is a vector? F Adding and subtracting vectors do you nd the you perform magnitude of a vector? CIGOL Multiplying Finding the a vector by magnitude a of scalar a vector C Finding Using the the dot dot betweentwo Solving ATL product product of to two nd the angle using vectors Critical-thinking Consider 5 4 ideas from multiple D problems do operations on mathematical vectors? vectors vectors geometric How perspectives How can vectors geometric Can logic be used to solve problems? solve everyday problems? G E O M E T R Y Y ou should nd the two points already distance know how between 1 solve linear simultaneous 2 use the cosine rule the points: a (4, ( 7) and 3, Solve 3 distance of equations T R I G O N O M E T R Y to: Find b A N D 2) the 3x + 5y 2x + y Find the (11, and between = pair 5) (1, 1) simultaneous = each equations: 5 1 size of angle A. A 8 7 cm cm B 11 cm C Introduction F The What How map You can blocks to shows give is a do part in an vectors vector? you of nd Salt directions travel to in the Lake this east-west magnitude City, area of of USA, Salt direction, a which Lake and vector? in has City the by a grid layout. giving the north-south number of direction. lia 9th Ave 9th Ave rT A block m o d distance is the between e e rF 8th Ave two tS adjacent intersections. J I H tS tS G F tS tS D E tS C tS tS B A tS tS City 8th Ave 7th Ave 7th Ave 6th Ave 6th Ave 5th Ave 5th Ave 4th Ave 4th Ave 3rd Ave 3rd Ave 2nd Ave 2nd Ave creek canyon South Temple J E tS I H tS tS G F tS tS D E tS C tS tS B A tS tS 1st Ave 1st Ave E South Temple E3.1 How can we get there? 5 5 Exploration 1 Using the a intersection the H b c You to of and and can and use a column 1st and 2nd Street F Street and vector to means translations in instructions Avenue to the to get from: intersection of Avenue to the intersection of 3rd Avenue to the intersection of represent a translation from one point The column the a intersection the map, the the intersection 5th each and of a of usually A J Street A column vector A column vector C units left column and and Street start down 3rd and vector Avenue 4th Avenue and 8th 4 units for to to Avenue vectors describes an at your the nal the the the to intersection position d column has units up. down. journey from: intersection intersection the of intersection x a e to describe of after F a Street of and translation of : f translations on a coordinate component and a y component: x component tells you how far to move in the x-direction. The y component tells you how far to move in the y-direction. Continued E3 Logic grid. translation. The 5 6 of Avenue. c use 3 the Street below, Write b will down 4 Avenue 3rd vector Avenue. and Avenue 8th intersection GStreet For of 8th and right d means write and units c vector Using 3 words: b BStreet You and down Avenue. vector these CStreet 4 D column a c Street write Avenue of 6th A City, Avenue of 7th intersection Street Describe b of 3rd Lake another. The 3 Salt intersection Street the A map Street the G 2 1 on next page G E O M E T R Y AB is the vector representing the translation from A to A N D T R I G O N O M E T R Y B. y On this grid, 5 4 The position vector of a point is the vector from B the origin O to the 3 point. A 2 On this grid, 1 O is ofthe the zero is the Find It is the position 0 vector point How (4, 9) What the and B is the discuss the point 5 (6, 4). A to B you move 2 units right and 5 units down. 1 vector operation coordinates How a 4 relate to the coordinates of points B ? could Practice 1 and does Aand 3 AB Reect 2 1 From x 1 origin. Example A vector. would of you A nd you and the perform to nd the vector AB if you knew B ? vector BA from the coordinates of A and B ? 1 Write down the column vectors for these translations 6 on the grid. B 5 i AB ii AC iii AF iv GF v OD vi OC 4 G 3 b Write down the column vectors 2 for: A 1 i AD and DA ii EG and GE O 0 c Conjecture the relationship between vectors 5 4 3 2 1 x 1 2 3 4 5 6 1 of the form PQ and F QP C 2 d Write down the position vector E of : 3 D i A ii B iii C iv O 4 5 e Write down the point with position vector: 6 1 i 3 ii 1 2 iii 3 4 E3.1 How can we get there? 57 2 On this 0 grid, nd two 3 a points so that the 5 b translation one to the other is: d 1 4 c 4 from 1 3 y 5 H 4 3 A 2 D B 1 0 7 6 5 4 3 2 x 1 1 2 3 4 5 7 6 1 E C 2 G 3 F 4 5 3 On a clean grid, coordinates 2 of start the the point after Write a M ( 2, c R (11, the 4) to 2) Problem 2 CD . 4 Point A 5) Write has down position Show points b Write down down A, the column 4 the the three and b P (4, d T ( AB C 6) 5, 9 to Q (11, 1) to BC = U ( 3) 6, 3) DC 5 of points, and suitable vector 2 = on position pairs of 6 3 5 axes. point where C one transforms to the other translation A 11 vector vector B by a Write down solving 2 7 Write d 6) S (7, 4). translates: 6 1 that (3, = 3 vector N (1, to coordinates translation: c 4 down with each b 5 5 2 a 4 at point journey 2 3 of is shown on this 5th Ave section 2 of the Salt Lake The length The larger of city the map. journey is 4 blocks. 4th Ave journeys with a of page, length vector: a b 4 blocks. c, D labelled next tS dierent is the C Each on tS shows map, etc. 3rd Ave 5 8 E3 Logic the G E O M E T R Y A N D T R I G O N O M E T R Y f 7th Ave a 6th Ave b 5th Ave 4th Ave Tip Single e are 3rd Ave letter printed When some d in bold writing vectors c vectors by hand, countries convention is in the to 2nd Ave underline D F tS C tS tS B E tS A tS tS a, b, and they are with an them, in written arrow 1st Ave b Reect ATL Are on if they are any the What Vectors are of is the does it equal equal journey discuss journeys smaller represent not The and the starting if their for blocks that point in If have larger are to be map the equal. exactly dierent the same as the one the same This same directions, as each means that other? they instructions. even if the are Two length of equal vectors the same. position of the vector south has vectors are and 2 equal if doesn’t matter. Walking two blocks east and vector , Two the journeys components journeys they two two on map? mean if 2 shown no matter where you start from. 2 their then components if are and equal. only if and E3.1 How can we get there? e.g. others 5 9 Exploration 1 A hiker walks a Sketch b Write c Find her 2 3 due east and then 4 miles due north. walk. down the miles the total shortest distance distance she walks. between her starting position and endingposition. A 2 The diagram Find the represents shortest the distance vector from A AB to AB B. B 3 The the a Sketch b Find length other, written The the of is shortest vector, the of a theorem magnitude Example (4, the to represent distance or the this from C (shortest) magnitude of vector. to D in distance the vector. terms from The of one x and end y of magnitude the of vector vector v to is | v | components | v |, = a diagram called Pythagoras’ A a 11) vector to nd of represent the , perpendicular vector’s is given distances, so you can use magnitude. by | v | = 2 and B = ( | v | = = 8.06 6 0 (3 s.f.) E3 Logic G E O M E T R Y Vectors a and 2 | a | = But and 5 b = are b A not 7 magnitude: | b | 2 equal 7 = + because ( −1) they = 50 have two their vectors vector a 1 have same = though When and 50 and 5 Even the T R I G O N O M E T R Y components: = have 2 + 5 dierent a both 2 5 a b A N D has lengths a both direction. magnitude and and b are are the parallel magnitude For two same, and vectors they but point point direction. to be in A equal, in dierent opposite scalar they directions. directions, quantity must have does the a = −b not same direction. Numbers quantities. a scalar but 1 Find 2 the magnitude of each 24 a given a vector as Find 3 8 magnitude of is vector 6 The each vector. Give your answers in exact 3 a 1 2 b 4 also force you gravity 3 size 4 3 Find the 4 magnitude of or 13 2 Give For (your weight) vector 0 8 each a A (1, c A ( e A (11, pair 5) 1, AB AB and 6) 4) B (2, and and and 4) B (2, B (4.5, 11 7) 23.8) 24 8 f AB AB correct to 7 4 = 6 nd 24 = = B, AB c A 10 = points s.f. AB of 3 6 0.96 to 2 e correct f 0.28 4 6 = 5 b For nd = AB AB (down). answers 4 each and c 2 AB your 8 5 vector. 16 e d b d a magnitude f each 5 a 12 a 4 5 e 5 due has c d a quantity. direction 5 is quantity. form. to in c 4 the speed direction) experience 2 is vector: b a Speed velocity Force 7 scalar quantity, (dened Practice are 3 3 s.f. b A (4, 6) and B (3, d A (3, 5) and B (5.8, f A (8.7, 5.3) and 3) 11.2) B (2.1, 14.6) E3.1 How can we get there? 61 a Problem 6 Four solving points, A (1, 7), B (6, 2), C (3, 3) and D (2, 4) lie in a plane. = Show 7 Points Find AB that A and four CD B lie possible 8 The vectors u Determine the 2x vectors u plane, x and has such 10 x 3 and = B 7x of A coordinates AB that = (6, 2). 13 . v = values 2 and for and y x The a positions = 9 in are equal. are equal. y 7x 10 v = 2 3x Determine C value of How diagram do shows you two x + 2 x Operations The the with perform journeys vectors mathematical in Salt Lake operations on vectors? City: 7th Ave 6th Ave Journey 2 5th Ave 4th Ave Journey 1 3rd Ave 2nd Ave tS F D E3 Logic E tS C 6 2 tS tS B A tS tS 1st Ave G E O M E T R Y Journey 3 1 then 2 then 4 1 2 = Whole 2 journey do 6 Reect and you discuss notice 3 about: the relationship between the x components of the LHS and RHS? the relationship between the y components of the LHS and RHS? A translation as the AC To is add The sometimes vectors vector = AB can two The A to from B A called you to the simply addition followed + also BC resultant is AB by + translation BC = of AB resultant their a from B to C is the same AC and BC components. law: then = draw vectors C : add and You the from translation If AC T R I G O N O M E T R Y = What Journey A N D so diagrams that the the vector to add second that vectors vector joins the using begins starting a graphical where point the to method. rst the vector tip of the Draw ends. second vector: v u + v u This shows the result of performing both translations. A Using the vector addition law: OA + AB = OB AB OA You can rearrange You can also see this this to on AB the = OB diagram. OA Another route O from A to B B is: OB A or to AO O, + then OB = O − to B OA + OB = OB OA E3.1 How can we get there? 63 For any two Reect Explain Hence and is the AB why explain Example A points A and discuss BA + = OB OA 4 must AB why AB B, be equal to the zero vector. − BA = 3 point (2, 11) and B is the point ( 3, 6). Find AB Write Example A has Find values of (a, a 3a), and B has coordinates (b, b 6), and 3a = −2 2a = 6 Practice 1 Find AC components AB Solve 3 for a 3 pair BC 1 0 BC AB 6 4 8 BC 2 E3 Logic 4 1 9 BC and = BC 10 = 12 = 3 AB and d 2 = = and AB 11 = 6 5 and 2 b = vectors: = 6 e of and AB each = c OB b components – and . The b OA 4 coordinates the down 5 9 = 12 of of AB the AB are given equal in the simultaneous to the question. equations. G E O M E T R Y 2 Find the 7) A (0, c A (5, 2) and B ( 6, e A ( 0) and B ( 11, 2, 3 and and 3 . A (2a, b A ( c A (2a point Find a 3a 1) + + 1, 4, squared what Draw a 2 Explain 3 a b 4 + 3a b A ( 1, d A (3, 3) and B (4, 2) 9) and B (12, 9) 7) is ( 12, 3). Find the coordinates of point B. values of a and b for these coordinate pairs: the any Explain 7) and B (b 5) and B (2b draw vectors vector, for any which nd b 4) paper, why B (3b, 3, + 1, the have d, in that vector v For any vectors 3) of these vector and the same vector vectors is . not v, are v property. + v must parallel parallel to to any be parallel each of the to v other: others. . and multiplication any + common. has non-zero which k v For 2b vectors vector why b) 3 fourth Hence Scalar A the and a Determine For 8) coordinates: solving Exploration State 0) of 7 a On pair = 1 each 7 Problem AB 1, for T R I G O N O M E T R Y = 4 B ( BA and a AB 3 AB vectors A N D = u and v of are a if to each other. vector : and v, parallel any u = scalar k v value then u k, and k v v = are parallel. E3.1 How can we get there? 6 5 Example Two AB points is 5 have parallel to coordinates v = . A ( Find 1, the 4) and value B (2b, of b + 2). b Write the position Find Parallel 2b + 1 = 3k 2 = 4k b = −2 Write b Example Four that system of A (4, ABCD simultaneous 6), B ( forms 2, a 16), C ( 5, 12) and D ( 2, 7) lie in a and ABCD CD has Practice vectors trapezoid: are one parallel. pair of None parallel of the sides other so it is sides a are vectors u a 2 = and Determine the some parts book) a a a for each BC , side and CD parallel of the world trapezoid v = are 3a + 1 quadrilateral of opposite of DA vectors. is (andin dened as value of have to 1 parts A (2, 5) and B (b . 3 E3 Logic 2, 1 b). of the world The Find the value of to 1795, mathematical in v = exactly parallel. one In pair other this is called confusion a dates a coordinates parallel with sides parallel. + 3 back points 6 6 b trapezoid. trapezium. is for parallel. a AB solve solving Two other. 4 Problem 2 each and for AB , Look this The the −2 In 1 equations of plane. the AB multiples AB trapezoid. Find = are vector 6 points, Show the vectors the vectors. the USA to a reference dictionary that directly in reversed b accepted meanings of a published the day. the G E O M E T R Y 3 Two points 7 PQ P (2a, a 4) and Q (3b + 1, 2a T R I G O N O M E T R Y 3b). The position . 5 coordinates = have A N D Find the position vector of the midpoint of the line segment of a point vector 4 Four 5 points a Use b Determine Four vectors points Show 6 have that points OA 9u = to if Find and have AB b Hence c Given and show line DC DC in that u are = 19 u 2 A (3, the lines AB AB A (4, B (2, and and 6), 11), B ( CD CD 1, C (15, are are 9), 3) D (17, 5). 1) in and D (11, ve + 14 v, OC terms is of a = u and , 25 u + 5v and OD = 15 u . v 1 v = and A ( 1 show that ABCD is a rhombus. 3, 1), B (1, 3), C (4, 3), D (5, 1) and E ( 1, R points are two sets Use vectors of four points, each of which forms a to show that the three points P (5, 4), Q (10, 0) and R (25, on a straight Reect Why does show that discuss showing the On suitable Label 2 The the that three Exploration 1 the points if the PQ and parallel. 5 vectors lie on a formed straight by three points are parallel also line? 4 axes, vectors angle line line. and draw OA , between OA the OB points and and A (2, AB OB is on 4) and your B (6, 1). diagram. ∠ AOB A O B Describe 3 you Find nearest 4 how Use the and could . use Hence the nd cosine the rule size of to nd ∠ AOB, the size correct of to ∠ AOB. the degree. method in steps 1 to 3 to nd the angle Q a 12) are lie P, trapezoid. vectors 8 on 2), straight nd point. parallelogram. points the 5). and the the to length. Three From from O vectors: 1 7 the parallel. equal C (1, and origin is parallel. ABCD = 7), segments position that that coordinates + 9 v, OB a show the have AB Four coordinates vector PQ between the vectors . Continued on next page E3.1 How can we get there? 67 QR 5 The diagram Write down shows an vectors expression u and for v v u in terms of v u x v x = and u = v u y y O 6 7 Write down Show that expressions | v u| for | u | and | v | = Use the cosine rule to show that and hence that Another For is any two called the vectors dot and product. It is , written u the the dot the equation = Therefore u Example Find u the | u | = | v | = v | u | v you | v | have cos formed the scalar above, you can see × is that a scalar = = | u | | v | cos . between the vectors and . Find | u | and | v | = | v | cos θ + 4 × 5 Substitute in the Give Example Vectors a vectors and their your answer the to denition a suitable of the of and b = are perpendicular. Find the value of | a | | b | cos 90° = angle and b is 90° = Substitute 8) + (14 7x) ⇒ x = 0 = −6 E3 Logic between 90°, and 0 cos 6 8 accuracy. x a (8x product. 8 = = dot degree The b magnitudes. = Use a result quantity. 7 angle | u | −2 product, the . = 1 is v = = for product because From name quantity Evaluate the 0. in scalar a and b product. G E O M E T R Y If two vectors Equally, if a a b = Practice 5 1 angle Find the 4 0 b are then either between 2 perpendicular each a = , pair of b 5 4 16 4 13 2 8 Problem b are nearest 3 perpendicular. degree. 12 8 and 4 and the 2 0. and 4 d that a = T R I G O N O M E T R Y and 20 Show to 26 and b or b 2 a = 8 c then vectors, and a 2 and A N D are perpendicular. 1 solving 20 1 3 Two speedboats are travelling with velocities ms 15 7 1 and ms respectively, on an east-north coordinate grid. 24 4 a Show b Find 5 the Triangle Use the Vectors u 2 that angle ABC dot u has and v have between vertices are 3m + 3 to the their A (6, nd same speed. directions 3), B (2, 1) of travel. and C (4, 5). ∠ ABC perpendicular: v = Find 5 2m the value a of m b and a + a Write b Explain the 2 Vectors c boats product = 6 both 2 an why of that Problem b you involving need aand = 1 perpendicular. b equation values Given are 2 more a and b information to determine b a, determine the values of a and b solving 7 Find three dierent vectors perpendicular to the 8 Parallelogram OABC a Find the position b Find the size of has vertices vector of O (0, 0), A (4, 8 vector 9) and 2 B (6, 6). C ∠OAC E3.1 How can we get there? 6 9 9 A rhombus Find the OABC value of has a For the vectors a = = (b + c) = a b + a Consider the 2 OC + Vector D You (b How Can can use = 120° and | a | = 4. , verify that 1 a x b x c) = b = and a y b + a c c x c = b c y for any 2D y vectors a, b and c geometry can vectors logic vectors components. 5 c = 2 a = vectors a ∠ AOC c that c a Prove = and 11 and b = , 5 a a c 3 10 OA solve in be used everyday geometric Remember to that solve problems? problems? problems you geometric can add even when vectors you do not know their pictorially. v u u + + v v v u ATL Exploration 1 The diagram u 5 shows a pair of vectors a and b b Copy a the diagram and draw 3a b the vectors: 2b Start with copy for a new each a diagram. O 2 c a + b d a – b In this N is (the resultant e diagram, the vector M midpoint is of the of a a + and then b) b f midpoint of AB a b and B AC . M a Given that AM = a and AN = b, explain a why AB = 2b and write down a similar A b expression for AC Tip N b Explain Form a why MN similar = b a expression for C BC Remember MN c Hence show that MNCB is a trapezoid. Continued 7 0 E3 Logic on next page = MA that + AN G E O M E T R Y 3 Four a a points + b A, B, C and respectively, This sketch Copy the shows sketch D have where one and a position and b possible draw are pair points vectors a + non-parallel of A, vectors B, C and a D b, a b, a non-zero and on b, A N D T R I G O N O M E T R Y and vectors. b the diagram. b a O b This sketch Copy the shows sketch another and possible draw points pair A, B, of C vectors and D a on and the b diagram. O a b 4 c Find d Hence This expressions show diagram for that AB ABCD shows and is points a A, DC parallelogram. B, C and D A a AD = a + BD = 2a BC = 3a + b b D a 2b a B a Find AB b Find DC c Hence 3a show that and AB DC are parallel. C The word ‘vector’ think of a place to another. some other from one folklore a set of vector a insects on from and does originally also are to one use another. answer parallelogram to In generation headings to Latin as the referred discuss your a mathematics We appropriate How is in organism Reect was word, something word as in the next. an a ‘to carries contexts: because sociology, to that other vectors guide meaning And aircraft in in is a you You from transmit person aeronautics, and disease that a can one mosquitos they vector carry’. passes vector is ight. 6 to Exploration regardless of Why was it necessary in step Why was it necessary to state 3 the to step direction state that 5, a that and b 3c of a show vectors and were b not you a were that and ABCD b? non-zero? parallel? E3.1 How can we get there? 71 Practice 1 Using 6 the diagram, express the vectors below it in terms of u v and w: u A B v C D w a BD b Problem 2 The CA c BC solving diagram shows a regular hexagon F ABCDEF A a Find in terms of a and b: E B O b a b AB c OC d FO e AC DB D 3 Points P, Q and R form a straight line and have position C vectors R Q p, q, and r respectively. QR = 4 PQ P q a Express r in terms of p and p 1 b Hence show that q = r q (4p + r). 5 O 4 Points S, T and respectively, U form where a SU straight = 3 line and have position vectors s, t and u S TU s Express s in terms of t and T u t U O 5 In this diagram, a Find b The M is the midpoint of AB. OA = 3a and OB = u A 2b OM 3a point N has position vector ON where ON = 2OM M Show that AN = 2b O c Given that a| = |b and a b = 0, fully describe the quadrilateral OANB 2b B 72 E3 Logic G E O M E T R Y A N D T R I G O N O M E T R Y Summary A column vector describes a A translation. translation from A column vector has an x component and to C from is the A to same B followed as the by a translation translation from a A y B to C : + AB BC = AC component: is AC The x component x-direction. move in AB the A is to The the tells y you how component far tells to move you how in the far addition If representing the translation the resultant of AB and BC law: and then from B. AC The the vector called to y-direction. vector The sometimes position origin O vector to the of a point is the vector = the zero For any vectors BC = = two points A and B, AB = OB OA and − BA vector Scalar Two + from point. AB is AB are equal if their components multiplication of a vector: are equal. For If and then if and only The If magnitude of a vector is its the magnitude of , is v = and u = kv then u and given k: v are parallel. any two vectors and , the is called the dot product = A vector A scalar has both magnitude and For two quantity vectors does to be not have equal, a they v = = a direction. must have two b = vectors magnitude and Write a a if b a = or a down column translation of 5 vectors right a translation of c a translation from that and 4 represent: 3 Find AC are perpendicular then = 0 then either a = , b are perpendicular. given: up AB 2 left and 3 translation from (4, (9, 5) to 14) (7, to ( 9) 2, b AB AB and BA given 3) and B ( 2, A (4, 2) and B ( 3, c A ( 7, 1) and B ( 4, 4) d A ( 2, 7) and B (11, 7) 1 7 and 8 AB 1 = BC 9 = 2 the and BC 4 = 3 2 points: AB 6 = and 15 b = 5). d 0) 0 A (1, BC = vectors and 4 up c the 2 = a b practice b Find and and a a the a d cos direction. b Mixed | v | 0. Equally, same | u | direction. If 2 value by u 1 scalar length. quantity | v| any = For | v |, vector, if kv and any BC 4 = 0 5) E3.1 How can we get there? 73 2 4 Given that AB , b given the nd the values of Problem a solving 1 and = coordinates: 10 The u vectors 5a A (a 3, b A (2a, c A (a 3a 4 + + 6, 2) a) 2a and and + B ( B ( 10) b, 2b, and 2b Determine + 9, b + 11 3) For the B (2b A ( −3a, a − 2 ) d B (11 + b , 2b and 4 + the points 1, b possible with the magnitude your answer of in each of exact 5 4 a b 12 these 3 13 of a A ( 3, 2) and is parallel to 2 v = Find the value of b 9 The diagram shows ve points O, OX = XB = a B, C andX. B and 16 A, d 15 values vectors, c 2 form. 12 2a 4): giving are coordinates Find a + 7 8 + 1) AB 5 v = parallel. 1) b) B (2b 2 and a a + = A CX = XA = b a X b a 6 M ( 3, 2) and N (2, 5). Show that OABC is a b Find 7 a Find, b ON correct to the MN nearest c degree, parallelogram. NM the C O angle Problem solving between: 3 2 a and 1 7 1 4 b 13 The 1 5 3 c 2 a quadrilateral OABC = OC a = and OA 2a = b. Lines OB and AC and shows AB diagram and intersect at B X 4 2 a C a Explain why OABC is A X Problem a solving trapezoid. b 2a 8 From of the list vectors the nine which Determine of of are which vectors parallel vector is below, to select each not pairs b Show c Find 6 to 20 16 20 12 18 36 15 5 8 25 45 9 15 4 6 9 Show that the 1 vectors 9 Review in to each D: By b) for some to explain constant k = b + m (2a OA – + b) AX , for show that some constant m. Hence which nd X OX and divides determine the ratio are 2 other. context Applying mathematics these questions, a oor cleaning robot has been in on appropriate mathematical the oor of a large room. It measures progress solving authentic real-life across the oor in 10 cm units, so the in the strategies situations 1 vector represents a movement of 10 cm 0 Think about how magnitude, direction, the dot x-direction. product, in AC . contexts select when (a + considering OX its ii. k OB 30 placed real-life = on In Objective OX lies and 4 perpendicular 8 b O X f a + AC d e = any others. OB other. parallel why that etc. relate to the questions being asked. 1 Show 3 , 4 74 E3 Logic that if the robot travels on a it covers a distance of 50 cm. vector of G E O M E T R Y 2 Find, correct travelled by to the the nearest robot as it centimeter, moves on the each distance 5 The its vector. robot axes is are placed not in lined A N D T R I G O N O M E T R Y another up with room, the PQRS, but sides. R 3 2 a b 7 9 4 15 d 3 40 e f 3 6 c 25 S 20 y 3 In a rectangular sothat the the room, x-and the robot y-directions is are positioned the edges of Q O x room. The robot 25 starts in one corner at (0, 0), travels P on until 0 0 then it reaches another corner and The robot until it reaches a third corners to 2 Find the area of the room in be 10 m OP Write down the vector which would location of robot to its starting The robot room Find 4 The and the travels then total along distance robot is put ABCDEF. It starts inside room. OQ in the at two sides back to which room is Its x-direction 25 OS and DE and its y-direction = 15 a Find PQ and b Show that c Find and PS below, walls PQ and PS are perpendicular. SR parallel to Determine parallel to whether SR and PQ are parallel. AF, determine whether the room is AB, rectangular. CD somewhere is is 50 the Hence BC 2 start. travelled. L-shaped O, of the = OR = d the room’s return point. straight 34 45 c the follows: 30 the as = b the corner. 60 a nds on Justify your answer. FE 6 D The robot is placed at O, somewhere in a E four-sided the room, room. U, V, It W nds and the four corners of X B C y You are given 15 OW OX that OA 14 = , OC 30 a Find vector b Find the the 2 robot and OE and the 22 Hence nd c Determine d Calculate the vector distance which the is 50 = 0 a Find UV b Hence c Show and is a XW 25 distance from A to E show that and that VW is the room trapezoid. perpendicular to both XW OF from longer, perimeter UV position UX 22 0 = 15 AE 32 determines = 40 information: = 25 = process, OV F A mapping vector = its following x O In the and C AC to or area F CE of the d Find the area e Find the size of of the room. ∠VUX room. E3.1 How can we get there? 75 How to stand out from E4.1 the crowd Global context: Objectives ● Making and ● Using Inquiry inferences standard Identities about data, given the mean F deviation dierent forms ● of the standard deviation and relationships questions How do you deviation ● What ● How is of the calculate a data the standard set? normal distribution? formula SPIHSNOITA LER ● Understanding ● Making ● Using the inferences the normal about standard distribution normal deviation C distributions and the is the deviation’ meaning of represented ‘standard in its dierent formulas? mean ● Can ● Do samples give reliable results? D ● Using mean ATL unbiased and estimators standard of the population we want to be like everybody else? deviation Communication Make inferences and draw conclusions 4 3 12 3 E4 1 Statement of Inquiry: Generalizing can help 7 6 to and clarify representing trends relationships among individuals. S TAT I S T I C S Y ou ● should nd the mean frequency of already discrete grouped from 1 know a tables This how table gives understand 4 5 Frequency 8 29 33 35 95 table gives the 2 and for w the chia the weight seeds. mean (g) of an Frequency < 75 10 75 ≤ w < 80 22 80 ≤ w < 85 38 85 ≤ w < 90 10 these grams weight. 70 ≤ w Dene in Calculate terms: population a b sample ultimate ● How ● What do is Exploration temperature in of between population recorded grade. 3 This a The for mean 2 Weight, The grades the 1 estimate F exam Grade 80packets a the Calculate and data dierence P R O B A B I L I T Y to: 200students. b ● A N D La you the sample measure calculate normal the standard dispersion deviation of a data set? distribution? 1 on the Crieux, rst day France of and Temperature La of Crieux, France the rst ve Betzdorf, months of the year was Luxembourg. (°C) Betzdorf, Luxembourg January 10 18 February 16 10 March 14 13.5 April 12 14 May 18 14.5 Continued on next page E4.1 How to stand out from the crowd 77 1 For this data, tendency When there two is called 2 sets of another dierences the Copy calculate (mean, data between and in the range and an statistical standard the mode and median). experiment measure data sets. that You the three What have you will measures do you the can now same use of central notice? to mean help explore and range, discover this measure, deviation. complete this table for the La Crieux data. Calculate the mean A of the dierences, and the mean of the squares of the tardigrade tiny animal lives Dierence (°C) recorded mean of the of a that variety environments, from the tropics to temperature the 10 in temperature dierence and a between Square Temperature is dierences. Also 16 − 4 polar regions. known Water as Bears, these 16 tiny can creatures withstand 14 temperatures 12 ranging 273 18 Mean of dierences = Mean of of dierences Square mean of 3 Determine the mean root 4 of of the from 5 the Decide, Reect ● Squaring do of this and Why we of the the of the squares whether original algorithm the is of that squares why the mean best for need of the represents temperature using and you root of of the square take the squares dierences to = the = root of square dierences. dierences the or the dierence mean (deviation) values. mathematical notation and vocabulary. 1 dierences numbers Why of explain dierences the square mean Hence, discuss large mean? for reasons, mean ● 78 mean with the units squares. squares Generalize the the of squares makes between them important? E4 Representation even the data larger. and How the does mean? that impact °C from to 150 °C. S TAT I S T I C S In to Exploration represent larger mean may The how be is close small a is of original units dierences the The a square measure of values are deviation shows that standard the the mean gives of the the the are gives more data positive weighting further mean standard dispersion to deviation the also root called data of It because dispersion is from mean. important deviation standard away of values to the from the these P R O B A B I L I T Y squared deviation. that gives an idea of mean. data the values same are close to the the units of the as data. The standard The notation calculated the from signicant. measure the The original which more standard mean. Use squaring deviation deviations, deviations A 1, the A N D deviation used for Greek a for whole letters shows the = mean ● = standard of standard population for ● how the representative deviation or for a populations the depends sample. Use population ● deviation on The Roman ● mean is of the whether it convention letters x = mean s = standard of for the data. is is: samples sample deviation x of Standard to mean x means this , In the sum the µ) (x formulae sum sum 1 also use the Greek the symbol sample Σ (upper case sigma) of ’. notation Exploration of population deviation ‘the Using the of of the (called all you all the x values. sigma values found the notation), divided standard the dierences the squares the mean by the the mean number deviation between the of by data a of set of values is values. calculating: values, x, and the mean, 2 µ) (x of the dierences Tip 2 Σ(x − µ) of the squares of the dierences You n 2 Σ( x − can standard calculate deviation µ) the square root of the mean of the squares with your GDC. n Most for GDCs the standard instead E4.1 How to stand out from the crowd use sample deviation, of . 79 Example At a 1 summer weight of weights, a in 18.3, carnival, small goat. a small The crowd rst nine of people people to are trying guess give to guess the the following kilograms. 21.6, 22.2, 24.0, a Find the mean b Find the standard c Write a Mean down 20.4, 17.4, 14.9, 26.7, 23.1 weight. what deviation the = of the standard = 20.96 weights. deviation (2 means d.p.) in The this nine context. weights b are Make the a population, table to x 18.3 20.96 2.66 7.07 21.6 20.96 0.64 0.4096 22.2 20.96 1.24 1.5376 24.0 20.96 3.04 9.2419 20.4 20.96 − 0.56 0.3136 17.4 20.96 − 3.56 12.674 14.9 20.96 − 6.06 36.724 26.7 20.96 5.74 32.948 23.1 20.96 2.14 4.5696 = n c = 9 This implies spread No, of you’re you’re not exclusive because twisted are 105.5024 up not to 8 0 seen mean love at a a the the the dozen goats nuts or that’s This nuts estimate heavier photo either. and for When with weight kilograms things Morocco, their branches. often the 3.42 looking seeing to of that is are E4 Representation is 20.96 lighter been an who that more or retouched Argania climb grow ripe, goats on the in kilograms, than tree, them its the and almost do so thorny, Argania them at a mean trees time. but with weight. a so organize use Greek your letters. calculations. S TAT I S T I C S Practice 1 For each then in set a of data, rst calculator. nd the Explain mean what 3 standard deviation deviation by hand, represents b 2 2 4 4 4 5 6 6 8 9 13.1 20.4 17.4 21.0 14.8 12.6 16.5 d The 15 cm 17 cm 14 cm 44.3 kg 41.5 kg 36.5 kg 12 cm 14 cm 18 cm 41.0 kg 33.6 kg 41.8 kg 14 cm 13 cm 18 cm 51.2 kg 39.2 kg 37.9 kg duration, in minutes, for a train 21 24 30 21 25 27 24 27 25 29 23 22 26 28 29 a Find b State Beatriz route ATL the standard context. c ATL and the a 2 P R O B A B I L I T Y 1 with each A N D the the has on mean and standard inferences a ve choice that of you routes occasions. The journey is recorded deviation of can from to draw school. times, the She to 15 16 20 28 21 Country 19 21 20 22 18 a Calculate b State 4 Find 5 The the the the route mean heights mean (in you and and standard would standard meters), of a deviation recommend deviation squad of of 12 and the 1.75 1.80 1.75 1.72 1.81 1.72 1.79 1.63 1.69 1.75 Find b A the new and mean player standard and standard whose height deviation of deviation is the 1.98 m heights of the joins of of train journeys days: journey. along minute, each were: route. with integers players heights the the consecutive this nearest each basketball 1.62 for her explain set 15 data. the for 1.65 a the timed recorded Motorway roads times on of squad. reasons. 1, 2, 3, 4, …, 15. are: the Find players. the new mean squad. E4.1 How to stand out from the crowd 81 Problem 6 a solving Calculate 3 Each the 6 7 number b Predict c Calculate d Comment One of now: is 6, known e to table the the 9, . standard deviation of this set of data: is then to the and increased mean standard and by 4. standard deviation. deviation. answers. in The the original new mean, data y, is set has changed, unknown but the so the data standard set is deviation 34 the two notation, is mean your x. set happen new on the 10 data will be Calculate Using in numbers 7, and 9 what the 3, mean This possible the is mean the sum values of a set of all of of the the unknown discrete x f data values values values divided by x in and a the y. frequency total frequency. A in formula a to Reect How is Example scores the in the standard for similar How is deviation for deviation of discrete data presented is: discuss formula table population? given table and the frequency The calculate frequency it the to 2 standard the formula for the discrete standard data in deviation a of 2 for this standard 25 players frequency in a table. golf Find tournament the deviation. mean are x f 66 2 67 3 68 4 69 5 70 4 71 4 72 3 and Continued 8 2 a dierent? E4 Representation on next page S TAT I S T I C S x f xf 66 2 132 67 3 201 68 4 272 69 5 345 70 4 280 71 4 284 72 3 216 Use x f 66 2 3.2 10.24 20.48 67 3 2.2 4.84 14.53 68 4 1.2 1.44 5.76 69 5 − 0.2 0.04 0.2 70 4 0.8 0.64 2.56 71 4 1.8 3.24 123.96 72 3 2.8 7.84 23.52 = A N D to P R O B A B I L I T Y nd the mean. 80 To nd the standard deviation, use the formula. The mean score Example The table is 69.2 and the standard deviation 1.79 the of total penalty penalty a season the for team. standard all 20 Find players the Number of minutes minutes hockey s.f.) frequency Total in (3 3 gives distribution is mean on (t) players a and 0 ≤ t < 10 3 deviation. 10 ≤ t < 20 9 20 ≤ t < 30 6 30 ≤ t < 40 2 Continued on next page E4.1 How to stand out from the crowd 83 Total penalty Mid-value minutes 0 ≤ t < (t) f tf 5 3 15 (t) 10 10 ≤ t < 20 15 9 135 20 ≤ t < 30 25 6 150 30 ≤ t < 40 35 2 70 Use an to estimate calculate for the mean. Total Midpenalty f value minutes 0 ≤ t < (t) (t) 10 5 3 13.5 182.25 546.75 10 ≤ t < 20 15 9 3.5 12.25 110.25 20 ≤ t < 30 25 6 6.5 42.25 253.5 30 ≤ t < 40 35 2 16.5 272.25 544.5 Use The mean Practice 1 Find the number of penalties is 18.5 and the standard deviation is 8.53 2 mean and the standard deviation for each set of data. a b x 1 2 3 4 5 f 3 4 4 5 2 Interval f 1 4 5 2 8 0 9 12 13 3 16 17 3 20 4 21 24 25 2 28 1 c Interval Frequency 8 4 0 ≤ x < 5 10 5 ≤ x < 10 12 E4 Representation 10 ≤ x < 15 15 15 ≤ x < 20 12 (3 the standard s.f.) deviation formula. S TAT I S T I C S 2 The weights of 90 cyclists in a Number Weight bicycle race were A N D P R O B A B I L I T Y recorded: of (kg) cyclists a 40 ≤ w < 50 8 50 ≤ w < 60 27 60 ≤ w < 70 30 70 ≤ w < 80 25 Calculate i b the A an mean cyclist or 3 Copy and ii wear more without Problem for weight must deviation compete estimate a weight below a the weight belt if mean. his the or Find standard her the complete this 1 50 to 2 6.15 43 80.34 5.186 39.56 table standard 2.06 5.05 223 the standard weight table: 197 and is belt. 20 Copy weight minimum solving 10 4 deviation. below and deviation ll for in the the 5 missing values, 1.72 then calculate the mean data. MidLength (cm) f value 0 5 < < x x 5 2.5 3 10 7.5 4 ≤ ≤ xf ( x ) 10 < x ≤ 15 12.5 6 15 < x ≤ 20 17.5 7 20 < x ≤ 25 22.5 7.5 11.4 389.88 30 − 6.4 163.84 75 1.4 122.5 90.72 8.6 369.8 2 Σf = Σ fx = 347.5 Σf ( x − µ) = E4.1 How to stand out from the crowd 8 5 Exploration 32 students’ Test test scores score Frequency 1 The data thebars. is 2 were recorded: 1 2 3 4 5 6 7 8 9 1 2 3 6 9 6 3 2 1 shown Describe in this the histogram. shape of the The curve joins the midpoints of curve. 10 9 8 7 ycneuqerF 6 5 4 3 2 1 0 1 2 3 4 5 6 Test 2 Calculate 3 Determine 4 From a the State the b the mean where original how and the standard mean lies 7 9 x 10 score deviation on 8 the for the data, to 1 d.p. curve. data: many data items are more than many data items are within 1 standard deviation from mean. State how 1 standard deviation of the mean. c Find the percentage deviation The data The in to graph is 8 6 the a the 2 has distribution mean of the data items that are within 1 standard mean. Exploration normal close of and bell-shaped is a a tailing normal distribution. symmetric o evenly curve. E4 Representation distribution, in either with direction. most Its values frequency S TAT I S T I C S Data on normal natural attributes, distribution. The 99.7% are such as normal of the data 95% are height, are within within 2 68% 1 If you you know can that infer ● 68% of ● 95% lie ● 99.7% This is the of a within €8000. values ±2 within and at for Salsa for of the looks follow like a this: mean within + σ μ μ follows a + normal + μ 2σ 3σ distribution then of is the you ±1 standard of deviations the of inferences deviation of the mean. mean. the mean. about sets of data. 3 have €5000. starting company dierent Sometimes deviations generally curve deviation deviations Erizo a mean starting Employees salary would of you at €41 000 rather salary rival with work representations dierent How within making del mean Which ● age deviations μ standard deviation a lie discuss La have ±3 Dierent C are standard distribution standard useful standard Zorro frequency data extremely Employees del the standard standard σ μ 3 and distribution P R O B A B I L I T Y that: lie Reect with 2σ μ 3σ μ weight, frequency A N D a of €45 000 company standard La Salsa deviation for? of a formula purposes meaning of ‘standard deviation’ represented in its formulas? may not be Tip given the whole set of data, but just some summary Most statistics taken from the raw data. Usually this includes Σ x (the sum of all GDCs have summary statistics 2 data values) and Σ x (the sum of the squares of all the data a the values). page, which gives 2 x and you input x a when set of data. E4.1 How to stand out from the crowd 87 Exploration 3 Here values are the data Population 2, 4, 4, , 5, 1 Find the 2 Find 3 Find 4 Find 5 Generalize the , the If 6 When ATL a 1 of you ndings of the ndings of with analyze 14 of Population 1. of Population 2. sigma notation: combined populations 2). using sigma notation: the 2 Expand 3 Distribute the sigma 4 Distribute the n: 5 Substitute 6 Collect 7 Substitute 8 Write like your Reect formula mathematical standard notation deviation (called formula sigma and represent for the population standard deviation: numerator: notation: = = and . terms. again. new and does the 4 Start the this ways. 1 your formula: discuss new information 8 8 11, ________ manipulate can Exploration What 10, 2. values using Population your can you variety What squared 9, 1. values Population the mean + squared 6, 2 ________ notation), in of Population the = the Generalize of mean then , = of your (Population 7 Population 4, mean Find populations: 7 mean , two 1 mean the for do = 4 formula you ________ for need to standard use E4 Representation to deviation calculate mean? standard deviation? it S TAT I S T I C S A formula to calculate standard deviation from the summary A N D P R O B A B I L I T Y statistics 2 x ATL and x Example The length follows a statistics is: 4 of time normal t, in are: a Find the b Make a a Mean = minutes, distribution for and a is and mean and to travel on 15 down runs. a mountain The summary . standard generalization skier recorded deviation about the times of the for times the ski taken for this ski run. run. min Standard deviation = 2.18 min Calculate b 8.6 – 2.18 = 6.42 8.6 + 2.18 = 10.78 standard side data 68% ATL of the Example The runs summary statistics between 6.42 min and 10.78 the mean. values lie 1 on 68% either of between the these. min. for a class of 15 students’ test marks are . a Calculate the b A class second 12.5 mean marks c Calculate d Compare (Assume a take values 5 and of will of the deviation the the test of for and 25 the mean standard students same mark performance marks follow had test. of all of deviation mean of the students two marks and for in classes normal the 63.5 Calculate the the a of the on the this standard second two this for class. deviation class. classes. test. distribution.) marks The Continued on next mean is page E4.1 How to stand out from the crowd 8 9 Substitute known values into the b formula for and solve for c so Therefore, d The of mean 15 and than for Assuming marks class, ATL in these 1 The the deviation of marks class s.f.) were are normally would students’ be swan since fully the assume is the 1926. grown mean generalization 2 The mean players slightly distributed, between marks would that all national In a mute the bird breeding swans data of 52.05 be lower 68% and of for the 71.95. between farm was and are follow 51 normal Denmark the class students’ For and the second 76. in and distributions. has Copenhagen, been data a on protected the weights collected: kg Find both 25. 3 mute 50 of class test rst questions, species of standard the the the 68% Practice In (3 kg and standard about the standard 1.80 m and Σ x and deviation weights of deviation 0.0432 m for mute of the the data collected and make a swans. heights of a squad of 15 football respectively. 2 a Find b A new and c In player standard Provided this 3 Σ x whose height deviation this data is of is the 1.98 m heights normally joins of the the distributed, squad. Find the new mean squad. make generalizations from data. Houston, deviation of Texas, 155 the mean annual rainfall is 1264 mm with standard Exceptional mm. are a One year Houston was b The this 9 0 an the rainfall follows a next year an saw 1100 normal exceptional was was mm. Assuming distribution, that determine the rainfall whether or a total of 1400 year. E4 Representation mm of rain. Determine than 1 in not standard deviation from mean. this year. exceptional more results whether or not the S TAT I S T I C S 4 In a year spent on a Find b Three 42 group, their the mean new State Problem 5 Twenty money of extra the and mean recorded night. The minutes joined minutes new each one number 25 the what students students minutes, Calculate c 45 homework spent year 30 you Σ x of = minutes, x, P R O B A B I L I T Y they 2230. homework. and reported respectively these would number was on group minutes including information the total A N D three need that on they their spent homework. students. to nd the standard deviation. solving ve students they were received. The asked about summary the amount values were of monthly calculated to pocket be 2 Σ x = additional Find the mean ● Can ● Do purpose from sample a and we of x $228 361 give to statistics of the the like to for all pocket this money: $85 and $125. data. results? everybody make else? inferences population. sample monthly population reliable be is their deviation versus want and added standard samples sample mean = students Sample key data Σ x and Two D A $2 237 For standard a about sample, deviation a population you can by using calculate the s x If, for example, Elstar all apples Elstar whole larger The you you apples. But population than the weights want can use to you sample (in to make need and, grams) make the of inferences mean as predictions to take into therefore, a an sample of about estimator about the account there 25 is whole the population average standard that more Elstar a for the apples deviation population likely to be a selected at 132 122 132 125 134 129 130 131 133 129 126 132 133 133 131 133 138 135 135 134 142 140 136 132 135 of weight is of of the much larger spread. randomare: Σ x The sample mean is x = = 132.48 g n 2 Σ The sample standard deviation is s ( x − x ) = = 4.28 g n n In statistics, you good estimates these values an unbiased value is an want of are the called estimator unbiased the sample same values ‘unbiased of the values for entire estimators’. population estimator (mean, the for the For mean. mean. standard deviation, population. example, The For When the notation the apples, etc.) they sample shows µ to be are, mean that = 132.48 is the g E4.1 How to stand out from the crowd 91 When you squared When a deviations you sample, number of the a an in an of sample As a result, the higher than better, and into if mean sum by of of sample standard the the number of population squared less deviation, one, 1. divide items in standard deviations n you This from gives the the sum population deviation the an of mean from by unbiased n the estimator deviation. items: estimate of the mean for of the standard the whole population is , estimate deviation for the whole is: estimate you used unbiased, account standard mean unbiased population the estimate the the n unbiased population an divide items sample the ● you of a from calculate population’s For ● calculate that the of the the standard population estimate sample of the may deviation standard population’s not exactly for the population deviation formula. standard represent the is deviation whole slightly This by range gives a taking of the population. Dividing population Reect ● Would ● Are and you 1 machine cm. A times 1.0 produced deviation when from an unbiased summary estimate statistics of the fact you are working a is: made sampling from would a be sample? Explain. absolutely necessary? examples. produces of 8 1.1 the by 1000 ball The 1.0 standard the ball bearings bearings results in 0.8 that each taken day from centimeters 1.4 deviation machine is of the 1.3 with the a mean production diameter line and of the are: 0.9 diameters of 1.1 the ball bearings day. Continued 9 2 whole 5 inferences measured. Determine calculating 6 sample diameters for discuss trust specic Example A standard there Give formula E4 Representation on next page 1 the rather alternative n for with The by compensates that only sample than with the population. S TAT I S T I C S A N D P R O B A B I L I T Y x Calculate 1.0 (1.0 1.075) 0.005625 1.1 (1.1 1.075) 0.000625 1.0 (1.0 1.075) 0.005625 0.8 (0.8 1.075) 0.075625 1.4 (1.4 1.075) 0.105625 1.3 (1.3 1.075) 0.050625 0.9 (0.9 1.075) 0.030625 1.1 (1.1 1.075) 0.000625 To = estimate deviation 0.275 of production) 0.1982 Objective iii. apply You must estimate D: the decide for the appropriate ATL Practice 1 Each had for a 10 an in you days, The 12 arrive On whether population need the standard in the in population from a sample (day’s use: d.p.) real-life strategies standard deviation, contexts successfully deviation and for baby the recorded minutes 0 whole 25 Auberon times 5 estimate farm, then of the to reach data correctly set apply a or solution an the are 14 how shown 2 standard many late of 8 how 9 many minutes rabbits are born one week. Their weights in grams 480 501 462 475 460 470 430 485 435 425 465 456 475 435 466 482 455 462 435 462 478 455 information, of the late buses town. 452 this bus 6 453 deviations his here : 5 deviation minutes 450 From standard 4 arrived. Find mathematics mathematical (4 the . formula. day 10 2 Applying selected cm the and make weights for a prediction the whole about the mean and are : standard year. E4.1 How to stand out from the crowd 9 3 3 The summary statistics for a sample n of the life given in mean length the and of table. batteries are Calculate the standard deviation of 25 38 750 Σ x the 2 Σ x batteries in the Problem 4 Katie for solving recorded 50 days. 60 100 000 factory. the The number results are of passengers shown in a carriage on her train each here : 1 7 6 7 7 6 7 6 7 8 8 2 10 6 10 10 5 12 5 8 6 8 10 8 9 3 7 12 9 5 8 6 7 5 9 11 12 4 9 6 7 8 9 7 9 11 7 13 14 15 a Construct a b Comment c Estimate d Make tally on the some chart the to shape mean and inferences represent of the the data. distribution standard for day Katie of deviation to report the of on the her representation. whole train. ndings. Summary The standard dispersion deviation that gives an is a measure idea of how of Using close how A data values representative small standard are the to the mean deviation mean, is of shows and the values are close to the mean. The values of all the units of the x deviation original means Using this the are the same as the in x f , formula A of of formula a sum of all the the x sum of all calculate population 9 4 discrete frequency table is , the sum divided by the total frequency. to calculate the standard deviation for data presented in a frequency table is: mean values. of a set of values the values divided by The normal Its the standard is: E4 Representation distribution with most is a symmetric values close to the the values. to of units mean number set data. notation, the a values distribution, is a of discrete standard of the A data mean thus data. that the the data original notation, deviation A and tailing frequency formula to o graph evenly is a calculate in either bell-shaped standard direction. curve. deviation 2 from the summary statistics x and x is: S TAT I S T I C S For a sample of n items: The alternative unbiased an ● unbiased whole an ● unbiased deviation Mixed In estimate population , estimate for the of is the the of whole mean for sample the 1 calculating population an standard deviation from summary 3 recorded statistics is: . standard population is: and 2 the data provided is Bernie the weight of food in grams his for ate each day. Here are his results: population. Day Find the each data set: mean a 3, 4, and the standard deviation a 2, 21 3, kg, 4, 21 5, kg, 5, 24 6, 6, kg, 1 2 3 4 5 6 7 8 9 55 64 45 54 60 50 59 61 49 of Food b for the the mean, hamster 1 of P R O B A B I L I T Y practice questions the formula estimate A N D (g) Find the mean 25 kg, 27 kg, 29 weight of food b Bernie assumes consumption 3 4 5 f 2 3 2 the standard hamster deviation ate over of the the 9days. kg c x and 6 Write c One down day Should the is that his the be food distributed. inferences hamster Bernie hamster’s normally eats he 25g can of make. food. worried? d Interval Frequency 4 The summary 1 − 5 2 lambs 6 − 10 4 Σ x 11 − 15 4 a Show 16 − 20 5 b The on a statistics farm for the weights of 100 were: 2 = 425 for kg farmer his special lamb Charlotte buys 20 strawberry plants for She sta other 4.25 wanted to see feeds half each day with attention. born water ne. to kg = 1.5 and if produce any half with a special strawberry He weighing Calculate guidelines lambs decided needed between that 2 any how many and 6.5 away from the mean these plant valuesare. food. After one strawberries on month each Number each 15 13 12 of of fed special 14 15 Analyze eect of with 17 the fed with 16 strawberries 17 data using strawberries 17 Number records the amount of nd 19 12 on 10 each 11 12 food 14 15 there strawberry 15 plant plant whether special on water strawberr y 19 to the plant. plant 15 she kg standard and deviations the = 2031.25 her was garden. µ that = 2 21 − 25 2 Σ x is 15 an plant food. E4.1 How to stand out from the crowd 9 5 5 For a particular data set, the summary statistics Problem solving 2 Σ are: f = 20, Σ f x = 563, and Σ f x = 16 143 7 Find the values of the mean and the Samples of water were taken from a there were raised river near a standard chemical plant to see if levels deviation. of 6 In a biscuit biscuits factory were a sample of 10 packets of lead. the Ten table samples below. The were units collected, are g shown per in liter. weighed. 6.3 9.6 12.2 12.3 10.3 12.1 10.3 8.4 9.2 4.3 Mass 196 197 199 200 200 200 202 203 203 205 (g) a a Calculate the mean and standard Use this data standard b To make predictions standard deviations about of all the the mean packets and the in the factory, which values and standard deviation of would 1 Dr to in measure mean and amount of lead in Over 10 g per liter of you Comment lead on in water whether is the lead use? should be investigated further. context Roussianos Saturday the the the levels Review for river. dangerous. mean predict deviation of b biscuits to deviation. asked their his cardiology systolic morning for blood ten patients pressure each weeks. This for table shows dierent standard the values treatments of the recommended yearly mean and deviation. Standard Systolic pressure is the pressure in the arteries Mean Treatment deviation between muscle the is beats resting of the and heart, relling while with the heart blood. low <75 blood pressure <10 treatment Here is the data for three patients. 75 Patient 85 no <10 treatment 1 high >85 95 95 87 92 100 84 87 90 87 96 pressure any Patient value to 76 75 80 Patient 81 tests needed mean the and yearly use the statistics sample and data therefore 76 80 82 80 3 65 100 76 98 58 75 76 98 66 75 9 6 the estimate help 75 more >10 treatment 2 Calculate 78 blood <10 E4 Representation to determine the treatment for each patient. S TAT I S T I C S 2 80 as people soon were as they asked to woke up measure in the their pulse 4 rate In at morning. one the given They after were a 5 asked km run, to repeat and just the town, birth in summary statistics before are: the mothers their rst P R O B A B I L I T Y were child. asked The their results age are table. measurements going to bed. Age The 300 of A N D Σ x = and 6000 at birth rst child of Number of mothers 2 Σ x = From 452 this standard information, deviation inferences 3 Birth 450 that weight summary can of be follows statistics nd each the data drawn a for from normal the mean set. and State the of 21–23 20 24–26 30 27–29 42 30–32 53 33–35 52 36–38 43 39–41 25 42–44 12 45–47 8 the data. 50 15 the distribution. weights 18–20 The babies 2 in a a hospital From be b If this drawn a risk. less Σ x data, from baby’s standard at were state the weight deviation Find than x a kg = 160 the and Σ x = inferences 524 kg that can data. is less than below value are kg x, so the that considered 2.5 times mean, babies to be the the baby who at is weigh risk. a Predict a for b a mean mother’s this The age and at standard the birth of deviation her rst for child, town. summary statistics for a dierent sample Σ x = 7500 and Σ x inferences that can for of 30 300 years ago, women were 2 Reect and How you have = 190 000 be drawn State from the the data. discuss explored the statement of inquiry? Give specic examples. Statement of Inquiry: Generalizing among and representing relationships can help to clarify trends individuals. E4.1 How to stand out from the crowd 97 E5.1 Super powers Objectives ● ● Evaluating numerical positive or Writing numerical exponents MROF ● Inquiry negative as expressions fractional with ● a F exponent expressions with How do you afractional ● fractional questions radicals How to do evaluate you simplify a number with exponent? use the rules expressions of with indices fractional exponents? Using the rules expressions fractional of that indices contain to simplify radicals and/or ● C exponents How are rulesof ● How the rules radicals do the rules simplifyradical ● D simpler and the of indices help with decimal simplied? always better? Critical-thinking Analyse parts Is indices expressions? expressions exponentsbe ● ATL Can of related? complex and concepts synthesize them and to projects create new into their constituent understanding 5 1 10 3 E5 1 Conceptual understanding: Forms can 9 8 be changed through simplication. N U M B E R Y ou ● should use the already multiplicative know rule how for 1 to: Simplify : exponents 3 a ● use the rules of radicals to 2 (x 2 4 ) b Simplify (2 2 2 ) c (2 x 3 ) completely : simplifyexpressions 128 a 45 b c 60 × 3 8 ● evaluate expressions with 3 Evaluate: 1 1 unitfraction 3 2 a 4 d 64 b 8 e 64 1 evaluate expressions with 4 negativeexponents 1 fraction 1 3 f leaving where 1 b c Fractional F For How do you evaluate ● How do you use ATL any positive Example 2 2 e 2 a 2 f 3 5 exponents ● fractional 2 as 3 6 1 d answer necessar y : 1 1 your ( 0.001 ) 2 4 32 3 Evaluate, a 5 c 2 ● 1 exponents the a number rules of with indices a to fractional simplify exponent? expressions with exponents? real number x, and integer n, where n ≠ 0, . 1 Evaluate: a b c a Using the multiplicative rule for exponents, b a (x c Here, Practice 1 b ) Work 1 out the value 1 1 b 4 the : denominator has been rationalized. of: 2 a x 1 1 ab = 1 4 1 1 3 c 16 1 2 d 8 1 25 1 1 1 4 e 2 f 9 27 3 4 g 2 27 3 h 25 1000 E5.1 Super powers 9 9 2 Simplify and leave your nal as a power of 3 (4 x ) ( 27 x b 6 3 2 x ) ) 1 1 1 × x f Problem 3 Write each 1 1 3 2 2 x ÷ x g 100 × all x ≠ 0 expressions. 1 2 2 x for that 1 4 2 x 2 x d e 4 3 (8 x c Assume 1 1 1 1 a answer x (9 x h 2 2 ) × 9x solving of these using exponents instead 3 a of the radicals. 1 1 x b c 4 x x 4 Solve: 1 1 1 x 2 = 2 y 3 a b 9 = 0.3 a Using the multiplicative for exponents (x b ) ab = x : 3 1 3 2 (x ) 2 = x = x 4 1 4 (x rule 3 3 ) 4 2 3 3 What ATL do expressions Exploration 1 Copy and Using with fractional exponents like x or x mean? 1 complete integer this and table: unit Using a radical Using fractional A fraction exponents unit fraction exponents hasnumerator 3 (x ) (x ) x 5 3 (x ) 2 (x x ) x 2 2 Simplify (x ) 2 and (x 2 ) . Are (x ) 2 and (x ) equivalent? m Generalize 3 Copy 10 0 and your result complete, for using (x ) your E5 Simplication where result m and from n are step 2: integers and n ≠ 0. 1. N U M B E R Reect ● Did Is discuss everyone inthe ● and table there in in more the 1 class get Exploration than one the same results for the last two rows 1? way of writing x andx in the other two columns? For ATL any positive Example real number x, and integers m and n, where without using a and could also calculation Which Write 1 Simplify a help these method, simplify or = the the . same one in expressions Complete answer as Example with 2? fractional expressions without using a 2 2 2 3 3 8 b each 27 c fraction and an integer. why. exponents. 25 d 64 e 2 3 125 f 343 of x f (32 solving of these using 4 2 x b Where exponents 3 c applicable, x d leave 1 4 3 b × x of x your nal answer x as a 1 4 3 × radicals. x 2 2 c the 5 x ) ( 1 2 instead 3 x ) ( 2 ) unit calculator. 3 3 a 2. Explain 2 (x into the Example 3 Simplify. a you this: gives 3 3 3 this this 4 Write a to – exponent 2 like that the 2 Problem 2 verify easier hint Practice discuss simplify and was a 0, calculator. Split You ≠ 2 Simplify Reect n d (3 ) power 2 2 5 e (x 2 2 2 3 ) 5 ) E5.1 Super powers 101 Example 3 ATL Simplify Using the multiplicative a = exponents,(x b rule for ab ) = x , gives : = = = = Reect ATL and discuss If 3 to The method in Example 3 dealt with the negative sign in the necessary, the by taking the reciprocal. Conrm that taking the cube root rst, rst, all give the same nal answer. Which method is in Reect or and squaring add you exponent wrote rst, hint discuss 2, to easier? help you simplify expressions with fractional exponents. Practice 1 Find the 3 value of each expression. Leave your answer as a simplied fraction. 3 3 3 2 a 4 1 2 these 1 3 2 1 16 4 e 27 3 2 c 49 2 2 1 3 12 × 16 12 ÷ 8 Problem 16 1 6 b 1 4 8 81 completely. 12 × 125 3 d expressions 25 1 4 125 2 f Simplify a 36 e 64 16 3 3 d c 16 9 4 b 25 × 343 1 3 1 2 2 ÷ 27 f 45 ÷ 15 solving In 3 Write down an equivalent expression that contains fractional question write 1 a 2 b 5 as d both powers numbers of the 3 same base. Simplify: Forexample: 1 1 3 1 1 1 2 3 2 a 3 2 × 4 9 b Rules C Writing of ● How are ● How do a radical 10 2 as 4 2 2 × 2 c indices the the an rules rules of of and indices indices exponent 3 can E5 Simplication 2 × 3 27 d 16 3 ÷ 2 radicals and help help rst 2 c 2 4 4, exponents. the rules simplify you of radicals radical simplify some related? expressions? expressions. 2 × 9 2 = 3 × N U M B E R Example 4 Write as a power of 2. Write Exploration 1 Use the rules of as a power of 2, Here are them by radicals to simplify: the expressions writing 8 as a from power step of 2, 1 written and using using the exponents. rules of Simplify exponents: Justify why are the two methods for simplifying expressions with square equivalent. Write Use the rules Generalize 5 Use the Use the of exponents Write as to show that for , to show that for and . for down the nth a rule root of ab ndings. exponents , . Why ndings. ; can equal exponents : Practice 1 of your rules For of your rules Generalize 6 simplify. b roots 4 then b a 3 number 2 a 2 each to show that , for where b not 0? . . 4 a single power of 2: 3 8 2 b 4 2 16 3 a 2 c d 4 2 Problem 2 Write as solving powers of prime numbers: 3 5 7 × In 4 2 8 3 a part b, rst write 8 4 7 b 9 × 9 c d 4 3 8 9 as a power of 3. 2 3 Write as products of powers of prime numbers: 3 a 6 b 50 f c 4 162 d 100 6 4 e 4 14 72 E5.1 Super powers 10 3 Objective iii. In 4 move Q4, C: write Write Communicating between dierent radical these exponents expressions expressions to simplify. as as 2 b mathematical exponents your 3 2 × of powers Give 3 a forms of to simplify prime answers them. numbers. as powers 5 4 9 × representation 9 the prime rules of numbers. 6 10 7 c Use of × 7 d 3 6 In n 3 4 a n e f g Reect Use a × a the and rules of g a and is h, prime. h m 10 4 assume m m 5 parts n 10 a discuss exponents 4 to justify why these expressions cannot be simplied: Write a general rule for when you can simplify products and quotients ofradicals. When with radicals fractional have the same exponents to radicand simplify but dierent them. For indices, write them The example: radicand number square ● ATL is under root the the sign. ● Example 5 Simplify Write Give When write radicals them 10 4 as have dierent exponents with radicands, the same E5 Simplication but base one to is the a the radicands answer power simplify of them. as a the as exponents radical, other, with with prime the same number base. radicand. N U M B E R ATL Example 6 Write as powers of prime a simplied radical, by expressing the radicands as numbers. Write the multiples Write Practice 1 Simplify these 3 2 × of using as primes. exponents. 5 completely, leaving your answer as a simplied radical. 3 a radicands radicands 3 6 2 × 2 b 5 2 3 4 × × 3 3 11 12 3 c 7 d e 3 11 5 3 7 4 5 3 3 f g 3 2 × 2 5 h 3 2 4 3 5 × 2 3 4 5 i 3 j 3 3 2 8 5 Write as simplied radicals, with prime number radicands. 3 4 3 16 4 a b × 7 3 3 12 3 3 c 12 × 18 d e 3 2 2 4 4 6 5 g 125 81 h 4 3 5 Problem Solve these 5 i 3 3 3 4 125 f 343 j 5 49 × 343 3 5 24 solving equations, where the unknown is always a power of 3. 3 27 1 y a = 3 b 9 = c 6 = 3 3 x 3 Other D z 9 exponents Think: ● Can ● Is expressions simpler with always decimal exponents be simplied? has in better? it, can A rational number is a number that can be written as a 1 Convert a 2 these 0.1 Write b the as a b decimals into Use your decimal a ratio expressed fraction. 0.375 fractions: c exponents 1.6 as d fractions, 0.3 and hence write these radicals: 0.3 3 and be ‘ratio’ 3 decimal expressions word fraction. a Exploration ‘rational’ the answers exponent c to step can be 2 d to justify written as why a e any 0.8 5 number f with a 5 nite radical. E5.1 Super powers 10 5 as π You cannot evaluate an expression like 3 2 or 5 without a calculator, because An the exponents are irrational numbers. However, you can simplify irrational expressions number π like π 4 3 × 3 or (7 , using the rules for exponents. π π 4 × 3 = + π How = could and denition why Practice 1 Write discuss of it a is radical dicult 9 d (3 ? this: means evaluate that . 6 these expressions as radicals of powers 1.25 b 2 get 5 is to 0.2 a you 7 Reect Suggest fraction. approximation for The a 2π 2 ) as 4 3 an (7 be Examples: written 3 cannot 2 ) prime c 100 1.5 ) e Problem numbers: 1.5 16 0.3 of 0.75 4 f 10 000 solving 0.2 2 Evaluate 32 3 Copy and . 4 your × 4 method. complete: 0.2 a Explain = 0.2 2 b 27 0.1 × 81 = 0.4 3 c 32 0.5 × 16 0.1 × 64 = 2 0.1 4 Solve x = 5 Simplify: 2 0.4 2 27 6 a 0.6 × 2 b 0.2 0.8 3 9 × 4 Summary For any positive real number x, and integer n, When radicals dierent where n ≠ 0, indices, any the write same them radicand with but fractional = exponents For have positive real number x, and integers to simplify them. m For example: m andn, where For n ≠ 0, = ( ) = : For When is The radicand is the number a power square root the the dierent other, write radicands, them as but one same base to simplify exponents them. sign. When is not radicals a power simplied 10 6 of have under with the radicals E5 Simplication have of into the one dierent other, radical. radicands, then they but can one not be N U M B E R Mixed 1 Work practice out the value Problem of : 1 solving 1 1 1 8 1 1 2 a 9 9 2 25 c 1 2 b 1 1 Write 27 contains 25 2 e expression that exponents. 1 4 b 3 3 c d 3 4 100 125 2 9 2 equivalent g 16 8 2 f an fractional 1 a 9 down 3 d Write as simplied radicals with prime number Simplify: radicands. 1 1 1 3 2 6 a (49x 3 2 ) b (64 x 4 3 ) c (4 x 2 ) × 3 3x a 4 4 2 b 16 24 × 36 5 c d 3 4 2 8 ( 3 Work out the value 2 2 3 4 b 0 000 ) of : 3 a 10 c Problem 3 3 1000 solving 2 27 d 9 10 Solve these equations: 2 4 Find the value of each of these x expressions. 1 x Leave your answers as rational a numbers. 8 = 32 b 5 = 4 2 1 a 4 2 b 5 2 3 3 8 these 9 5 × 64 expressions 11 2 d 9 as rational of prime Simplify, Leave your leaving of prime 5 125 b 0.9 81 b as simplied 0.1 0.4 × 5 c 9 0.2 × 81 0.4 × 3 3 9 e 0.4 125 12 36 0.2 12 d 3 3 8 4 12 × 64 4 0.3 16 3 64 answers 0.3 × 5 a your numbers: 0.4 25 1 1 1 16 numbers. 5 1 5 radicals completely. powers 64 a answers 9 3 3 3 c Simplify 125 = 2 x c × 9 c d 1 1 16 12 6 6 6 The simplied 25 5 b 16 × 4 c Simplify these expressions × 343 Without your answers as has been fractional encoded using exponents. using a calculator, completely. simplify Use your the following results and the completely. key Leave and 2 7 expressions 7 below surds 1 2 2 2 2 × 1 3 1 2 a quotation 3 Simplify: simplied to decode a quote by Stefan Banach. radicals. 4 64 3 3 a 16 × 4 8 b 4 12 × 48 c 4 4 Key: = L, = I, 2 = A, = O, 3 3 9 8 4 d e 4 × 3 4 4 × f 2 8 × 6 8 × 8 3 81 3 = M, 8 = D, = S, 1 = N 3 4 12 9 g h 3 4 27 12 Mathematics 1 1 1 1 1 1 32 2 1 5 15 2 × 20 2 18 10 10 2 2 1 5 27 3 4 15 2 3 .’ 1 2 1 1 1 1 1 1 1 3 64 12 3 3 × 64 3 4 × 81 2 you have 2 144 3 × 6 3 4 4 18 2 256 2 How 64 1 8 and 4 2 3 Reect 6 4 6 × 2 3 discuss explored the statement of conceptual understanding? Give specic examples. Conceptual understanding: Forms can be changed through simplication. E5.1 Super powers 10 7 2 Ideal work for lumberjacks E6.1 Global context: Objectives ● Evaluating Orientation Inquiry logarithms with and without ● a in space and time questions What does log b mean? a F calculator ● Writing an ● exponential logarithmic statement as a SPIHSNOITA LER ● Solving Writing exponential and solving C equations real-life exponential Using nd logarithms using a do to logarithms make problems solve? equations How can anything in mathematics be situations natural considered natural? logarithms ● ATL How easier D ● you statement ● from can calculator? ● ● How Is change measurable and predictable? Critical-thinking Consider ideas Statement of from multiple perspectives Inquiry: E6 1 Generalizing that can changes model in duration, quantity helps frequency establish and relationships variability. E10 1 E12 1 10 8 N U M B E R Y ou should already know how to: 2 ● use index laws 1 Simplify 2 x 5 × x Evaluate: 1 3 a ● rewrite surds quantities and with roots as 3 model a b real-life anexponential problem 2 2 c 16 Write with an exponent: exponents 3 6 a ● 1 5 with 4 3 9 b c 5 In 2007, the Zika virus was growing equation at a rate of 18% per week on Yap Island. Two people were infected initially. Use an exponential model to determine the number of people infected after 52 weeks. Introduction F ● What does log to b logarithms mean? a ● How can you nd logarithms using a calculator? x An exponential equation ● a is the base ● x is the exponent Exploration Write each Therst 1 Find the is in the form a = b power 1 statement one or is done as for exponent an exponential equation, and solve to nd x you. of 10 of 2 that gives the answer: 100 1000 10 000 0.1 0.0001 2 Find the exponent that gives the answer: 4 8 16 128 Continued on next page E6.1 Ideal work for lumberjacks 10 9 3 Find the exponent of 6 that gives the answer: 36 216 4 What patterns Determine do what Determine you notice? would what happen would to happen the to answer the if answer you if add you 1 to the subtract 1 exponent. from the exponent. In steps 1 to theanswer, 3 the you exponents can use are trial all and integers. When you can’t spot improvement. x 5 To solve estimate = 10 to 150, nd x estimate correct to the 2 value decimal of x and try it. Improve your places. x 6 Solve 2 7 Solve 5 8 You = 45. Give your answer to 2 decimal places. = 77. Give your answer to 2 signicant x can solve also use graphing exponential software equations gures. 1.1 to y graphically. x For example, the graph y 10 of to the solve 10 = 60, exponential draw function f Read (x) = 60 (1.78, 60) 2 x = and the the value graph of x at of y = the 60. intersection x f (x) = 10 1 to 2decimal places. 0 x x a Solve = 2 answer to 6 2 graphically. decimal Give your places. x b The Solve three 7 = 14 methods ● the ● trial ● graphical for inspection and solving Give your exponential answer to equations 2 in signicant gures. Exploration1are: method improvement Reect and ● you Would graphically. discuss use the trial 1 and improvement method or the graphical x method ● What 110 to are solve the the equation advantages and E6 Quantity 9 = 85? Explain disadvantages of your the choice. three methods? N U M B E R The trial and perspectives improvement on solving method and exponential the graphing method give two dierent equations. x Here is is another dened as method. ‘the In the logarithm to exponential base 10 of equation 10 = 500, the quantity x 500’. 1.1 You can write log 500 = x 10 log (500) Tip 2.69897 10 Using a calculator: log 500 = 2.69897… x = 2.70 10 The (2 log your You can use the equivalent button on d.p.) statements for to not calculator ‘log ’. You is do 10 x 10 = 500 and log 500 = x nd the need to enter 10 unknown exponent. Rewriting the exponential logarithmic statements statements changes number as the unknown Before variable from an exponent to a regular variable. Whenever you see calculators, an logarithms exponential or logarithmic statement you can use the equivalence concept it from another log any you two can positive numbers a and b, there exists a third number c so that write: published tables. or We the equivalent say gives base When that the of the a the c is calculate logarithms at b’. new logarithm In logarithm the and equations equation to base logarithmic b is called involving using statement the a of b’, or ‘the exponent statement the form. , argument exponents other . or This of the you is of a that called the logarithm. logarithms, allows a it to can see be the helpful . 49 When a not an exponential with base 10 are often called ‘common’ logs and written log statement. . x, base. you most does as means Logarithms On to equation Rewrite without button. 1 Solve = a perspective. Example x of the statement logarithmic ‘the answer solving rewrite from exponential in Modern calculators touch the values perspective. were For of to dierent consider 10. see ‘log’ written calculators allow this, you you without can will choose need to a base, the base use the you of can the change assume the logarithm. of base If base your is 10. calculator formula E6.1 Ideal work for lumberjacks 111 The Change of base formula: , where c is any new change formula in Example of base base. is derived E12.1. 2 x Solve 2 = 50 using a calculator and the change of base formula. x 2 = 50 Rewrite as a logarithmic Use = 5.64385619 = 5.64 Work Example (3 on your calculator. out x Find the value of The the equivalent Hence, Write 500 b using answers 2 logarithmic statement x = to 3 down log your x 10 = 150 calculator, nd c 64 the = value 60 of d x in an equivalent exponential statement = 2 b log 4 = c log 0.1 = for: -1 8 x = 5 e log 5 3 Write b = 4 f log b down an y equivalent 2 3 logarithmic statement 1 3 = 9 1 12 b 4 0 x 2 a = 3 = 0.125 E6 Quantity c 1000 = 10 2 each 3 log equal, x 10 s.f. 8 d are for: x = 45 case. e Give 2 your = an so for: 2 a bases as 1 down 10 10. x. = x a = base c s.f.) Rewrite Write of with Write 1 change formula 3 . Practice the statement. 6 surds as exponents. exponential the statement. exponents are equal. N U M B E R Use this table Powers of to help 2 you answer Powers of questions 3 4 – 6 Powers of 4 Powers of 5 Tip 3 3 0.125 2 3 3 0.15625 4 3 0.008 5 Learn results 2 2 0.25 2 2 0.04 5 solve and 1 1 0.5 2 1 0.2 5 0 0 1 1 2 3 4 3 8 3 2 3 4 9 4 4 27 4 16 5 81 32 Without log 625 = a 243 x b log log nd 243 the = 64 5 256 5 1024 5 f x log Without a log using 5 = a x b 6 Find value c of a log value 17 = of x to x b the log 7 Solve, = x g log a = 40 b Logarithms of stars; in are used geology semitones; inside nautilus of Solve these 5 in to measure Problem 8 3 the = value x of x d log 1024 1 = h x log 121 = 0.04 = x 5 x 256 = x log d 4 nearest = 4 log c 256 = x 2 hundredth. log c x 31 = x d log 3 x 3 = 5 = x 8 calculator: x a nd 6 using 0.625 3 3 log 2 3125 x. 3 the 625 5 x 0.125 log 125 4 calculator, 5 25 4 2 5 5 3 3 0.00001 = 1 2 4 calculator, 5 e 5 5 3 using 16 4 5 2 5 4 3 without calculator. 1 4 3 4 2 5 2 3 2 1 1 3 logarithmic 0 4 2 2 a 1 1 2 4 0 3 you exponential equations a 2 help 1 0.25 4 3 to 2 0.625 4 3 these x = 100 astronomy measure and shells c the perhaps whose to 4 x = measure intensity most of 85 the form apparent 2 a in = 90 magnitude earthquakes; beautifully, chambers d in nature, logarithmic music, as seen to in the spiral. solving exponential equations. 2x x a + 1 2 x + 2 2 x = b 4 3 2 x - 2 = x +1 c 9 2 1 In = 2 8, with x + 2 1 x d 2x = 3 3 2 1 + and 2 e 2x = 3 write them the use same the base laws 2 9 exponents. E6.1 Ideal work for lumberjacks 1 13 of Using C ● You an can How use do logarithms logarithms exponential equation logarithms into Example to statement one you solve as can make an to solve problems complex equations easier exponential equivalent logarithmic to solve? equations. statement Rewriting changes the solve. 4 , Solve accurate to 2 decimal places. Rewrite x 1.67195... = 2x = = 0.34 0.33567 + as a logarithmic statement. 1 (2 d.p.) Solve Practice Solve each 2 equation, giving your answer 2 x x 1 2 3 5 5 4 × 2 = x (2 5 d.p.) 2 = 4 3 6 2 × 2 2 x = 3 (2 s.f.) = x 6 (2 d.p.) x 2x 2 6 (2 s.f.) accuracy stated. 5 (3 d.p.) 5 (3 s.f.) 1 = 6 (2 d.p.) 3 8 = 16 3 You and can also decay select real-life use s.f.) an logarithms to solve equations that result from real-life growth problems. D: Applying appropriate mathematics mathematical in real-life strategies contexts when solving authentic situations Exploration use (2 3 Objective In of 2 = 7 ii. degree + 1 x = the + 1 2 1 to 2, you appropriate 114 will write strategy to an solve E6 Quantity equation it. to describe a real-life situation and then for x. N U M B E R Exploration An A amoeba certain one The a on a how number Time single-celled amoeba amoeba Determine 1 is 2 splits long of of it will amoebas take Write the number 3 Write A(t) as 4 Write and solve an and ● How do ● How could Example you of discuss know you when verify on amoebas to be = t. Copy t = powers of 1000 1 = an cell division. hour. There on the complete 2 t = is experiment. amoebas and A(2) of by every beginning A(1) as reproduces time t = amoebas the there 0 = 3 A(3) the t = slide. table: = 4 A(4) = 2. function. exponential equation to nd t when A(t) = 100. 2 to that use logarithms your answer to solve makes an equation? sense? 5 number of drosophila experiment is a Find population b Write c Find the an the for A(0) exponential an at depends amoebas that separate slide t = 2 Reect two microscope (hours) Number The into organism 200. The at exponential number of (fruit ies) population the end function days until in a laboratory increases of the for the the rst by 8.5% and the each second number population at of beginning an days. drosophila reached of day. 100 after 000 x days. drosophila. a Number of days ( x ) Number 0 of drosophila (D) 200 Growth factor b = 1 + r = 1 + 0.085 = 1.085 1 2 Exponential b a = 200, b = growth is modelled by 1.085 x y c = a(1 + r) where x is Rearrange Rewrite x After 77 = days as a to the number isolate the logarithmic of days. term in statement. 76.18 there would be more than 100 000 drosophila. E6.1 Ideal work for lumberjacks x 115 Practice 1 At the The 2 3 end of the population a Find the b Write c Predict A group of snow 2000 at exponential the year 15 in snow the increased population an of year then the population by end function which foxes the are 1.3% of 2001 for of per and P (t), the population introduced a city was 300 000. year. 2002. population should into a after exceed nature t years. 350 000. reserve. The number 0.4 t where Find 100 3 The is the how snow can be number modelled of years years after by since their the exponential their N equation = 15 × 3 introduction. introduction when there should be at least foxes. and 08:00 N many half-life Copy at t foxes of caeine complete one in the the table human for a body student is approximately who consumes 5 120 hours. mg of caeine morning. Time period Amount of Time (t hours) caeine (C 08:00 t = 0 120 13:00 t = 1 60 18:00 t = 2 mg) 23:00 a Find the common b Find the exponential c Calculate d The the ratio for the equation amount of geometric for caeine the in sequence. half-life the of student’s caeine body in after terms 35 of t hours. Each of eect hours Coco is starts (w) which is negligible there is only below a 0.02 mg. negligible Determine eect from the the time for a race training, Time (t, min) and she to records can run 1 70.56 2 69.149 3 represents 5 many run 10 her 10 10 km km in times 72 each The form week. minutes. km a times geometric sequence. Use w w to 67.766 4 66.411 5 65.082 her weeks 116 hours. caeine. = 0 and nd the decrease. Assuming period number solving training Beforeshe Week caeine after Problem 4 of it time will continues be before E6 Quantity to decrease Coco can at run the 10 same km in rate, less calculate than one how hour. = 1 rate of N U M B E R 5 A large lake decreasing has at a Make a b Write an c When a a population rate table to the show population how long Natural ● How ● Is Exploration exactly one 6 10% exponential Calculate D of year the due number model of 100 000 year for perch will of the falls take for perch. to perch P number below this The number of perch is pollution. after of to 2 perch 25 000 lake 1, be it at is a and P 3years. after at a t years. ‘critical critical level’. level. logarithms can anything change of it of per in mathematics measurable MYP Standard would grow and 14.1 with considered natural? predictable? explored the be interest how $1 invested compounded at in a bank dierent for intervals: annually semi-annually quar terly monthly weekly daily hourly ever y minute Innity is without ever y a oorless walls or room ceiling. second Author unknown The the number total The number continually In of times investment 2.71828… growing general, population P is all is called populations nal the interest is compounded is n. As n approaches innity, $2.71828… e and it is the base rate for growth/decay of all processes. growth the is the approaches that grow equation continually , are modelled by the where: population original r is the growth t is the time population when t = 0 rate period. E6.1 Ideal work for lumberjacks 1 17 Reect How and could the exponential To calculate If 3 formula be used for problems involving decay? the then The discuss natural growth the rate or equivalent the time you logarithmic logarithm is written can use logarithms statement as: with is , y base > e. 0. ln y. x Your calculator The rst mention appendix until The to Euler spiral skydiver e, Napier’s galaxy Example a of have on spiral, the an his the ln on the and in of an logarithm, logarithms, work cover where button, natural work completed logarithmic A should button. e was but it noted wasn’t in 1618 as ocially an named ‘e’ 1748. this shape book does is not a naturally alter but occurring the size increases. 6 jumps parachute. As o he a cli. falls, , his where Sensibly, speed his of the skydiver descent speed, , is has remembered modelled is in m/s speed of 40 and by the time t is to wear equation in seconds. Find: a his b the initial time speed it takes for him to reach a m/s. a Initial = Initial 50(1 speed 1) is = 0 speed occurs when t = 0. 0 m/s. b Substitute 40 for the speed and solve for t. Write = t = 8.05 1 18 -0.2 t seconds (2 d.p.) E6 Quantity the equivalent logarithmic statement. N U M B E R Example In 2000, an Assuming per year, 7 island that in the the Caribbean population was had a population continually of 2600 increasing at a people. rate of 1.68% calculate: a the predicted b the time taken for c the time taken for decrease at a population rate in 2020 the population to double the population in part of 2% per b to return to 2600 if it began to year. a Standard population equation. = The 3638.3 Use your calculator. population in 2020 will be 3638 people. b Double Rewrite = The as a the population logarithmic is 5200. statement. 41.258… population will double in 42 years. c For exponential Rewrite = The 1 a rate is logarithmic negative. statement. will return to 2600 people in 35 years. 4 Carbon-14 and as the 34.657…… population Practice decay, dating is a common method used to determine the age of fossils bones. 0.000121t One formula where A P femur the is used the bone carbon-14 to calculate percentage found found in in of an a the age t (in carbon-14 Australian normal years) left in of the aboriginal femur. an item item P (written burial Determine is the site = e as a , decimal). contains femur’s 11% of age. E6.1 Ideal work for lumberjacks 1 19 2 Radioactive substances decay half-life time for (the taken over half of time the and are often substance to described by their decay/disappear). b t Theformula used to describe this decay is A = A e , where A is the amount 0 left after time t, A is the original amount of the radioactive substance 0 and b is decay Iodine-131 has diagnosing issues a Find b Hence c Find start 3 the A the a half-life decay write how with biologist constant. with down the 8 days. thyroid constant many 3 of the b for of is a common iodine-131 formula grams It substance used in gland. for the iodine-131 if you begin exponential will be with decay present 3 of after grams. iodine-131. 28 days if you grams. monitoring a re ant infestation notices that the area infected by 0.7 n the ants and 4 n can is the be modelled number of population size. the initial b Find the population c Calculate group of 20 = 1000e after Find A A weeks a how by long rabbits after it is one will , the where initial A is the area in hectares, observation. week. take the introduced population to a rabbit to farm. cover After 50 000 t years hectares. the 0.6 t number of rabbits a Predict b Determine Give your the N is number how modelled of long answers to rabbits it an will by the after take 3 for appropriate exponential equation N = 20e years. the number degree of of rabbits to reach 400. accuracy. 0.8 t 5 The model where t is for the measured a Write down b Calculate The in of it wombats will take of a small Dutch 2010 2011 Population 5101 5204 0 in that were for town Year = wombats in a nature reserve is P = 50e the introduced original to the reserve. population to quadruple. the population is was modelled obtained by the for two standard consecutive equation, and 2010. a Calculate the rate b Calculate the predicted c Calculate the number 12 0 , years. many long P solving population Assume t how how Problem 6 population of growth, r. population of years E6 Quantity in until 2020. the population exceeds 10 000. years: that N U M B E R Reect ● What and do discuss you think are 4 the limitations of continuous growth and decay models? ● Why do you think ln is called a ‘natural’ logarithm? Summary x An exponential equation has the form a = b : Generally all continually ● a is the base ● x is the exponent growth or any exists a two positive third numbers number c so equation a that and you b, there can write is the is or the exponential the equivalent modelled that by , grow the population where: power P For populations are nal the population original population when t = 0 statement logarithmic r is the growth t is the time rate statement period. ; We say or ‘the In the the that c is ‘the exponent of logarithmic base of the logarithm a that to gives base the of b’, answer b’. statement logarithm a , and b is called a is called If then is , The Change of Mixed 1 Write of the base natural logarithmic 0. logarithm is written as ln common logarithm is written down formula: the equivalent logarithmic 4 Find the value of x to the nearest hundredth. for: x 7 = 23 b 10 = a 95 log 7 = x b log 12 = x 21 = x 4 2 x x 8 = 6 d 4 = c 47 log 312 = d x log 9 5 x e 2 12 = Write e 1200 down statement an equivalent exponential a log 125 = b 3 1 log = = 3 d log 9 log m = Find 2401 = 3 log of x without = b x c e 1 calculator: 20 d 3 × 3 f 3 × e = 20 x + 1 = 15 2 x = 45 + 1 = 30 the 9 = a x value of x without using a calculator. 1 2 2 x = 2x = g x = 2 × 3 Find x d log 7 log d.p. x b 8 5 + 4 3 x - 1 = 125 3 log log 2 5 2x e to b 2 x e a log 2 c x n value 16 of = x 20 4 x a value ln 5 = 4 6 the f x a 3 a -2 3 log 1000 the x 7 e Find = x 5 c 5 log 650 for: 7 3 = 1 = x c 3 + 3 1 1 = 6 x f log 8 = 9 x 8 3 6 6 = y. aslog y logarithm. x c statement practice statement a > equivalent the The argument y the x 6 E6.1 Ideal work for lumberjacks 1 21 7 The table price in below shows Canada from the average 1990 to movie ticket b 1994. in c Price of Calculate the Find the year average price of a movie ticket 2016. when the average price will reach $20. a Year movie 1990 ticket 8 ($) A kettle to cool. of water The is heated temperature and can then be allowed modelled by 4.00 0.2 t the 1991 4.22 T exponential is the equation T temperature (in = 100e °C) and t , is where the time in minutes. a 1992 4.45 1993 4.69 1994 4.95 Find the exponential model for the a Find the initial b Determine c Elizabeth the can ticket price as a function of t, Review of years in Charles Francis Richter and magnitude the of intensity. 1935 it It is formula earthquake a the an American who created which by scale, standard the quanties measuring logarithmic been earthquake One scale, earthquakes has was physicist Richter size 1990. context seismologist 1 since their and measure since of intensity. for modelling using the the Richter magnitude scale of an is: I c M = log 10 I n where M is the magnitude, I is the intensity of c the ‘movement’ and is the of the intensity earth of the from the earthquake, ‘movement’ of the n earth a on The day a normal intensity in as earth the from 250 000 this of is the 100 on microns. of the earthquake microns. on basis. movement intensity earthquake 12 2 the Oklahoma December, the day-to-day Determine the Richter E6 Quantity a normal Last movement was of recorded the drink is 40 the leave number temperature the after water 3 minutes. when the average temperature movie temperature. size scale. of it to cool. °C. Find how long she must N U M B E R 2 To calculate the pH of a liquid you need to 4 The decibel scale measures the intensity of + know the inmoles concentration per liter of the of hydrogen ions (H ) liquid. sound D where I On The pH is then calculated using the pH = - log (H is the the equation intensity decibel scale, ratio the = 10 log of purr a of , sound. a cat measures logarithmic D + formula: the using = 10 log 330 = 25.2 (3 s.f.) decibels. ). 10 Sound a HCl is a strong acid with a hydrogen intensity is measured on a trac light ion system: concentration of of 0.0015 Find the pH the Find the hydrogen HCl moles per liter. solution. Green: b liquid which has a ion pH concentration of of no ear protection needed. 1 – 75 DB a 9.24. Orange: ear protection recommended. 80 – 120 DB c A solution nor base) if is said its to pH be is 7. neutral Find (neither the acid concentration Red: of hydrogen to be ions which considered would make a ear The pOH of an aqueous solution measures of hydroxide ions (OH ) in a the the formula: pOH = - log sound determine + DB intensity whether or of not these ear noises protection solution, equipment using 120 the and number necessary. neutral. Calculate 3 protection solution (OH is recommended or necessary. ) 10 a a Find the pOH of an aqueous A chainsaw solution that has a hydroxide ion concentration b moles × 10 per an intensity ratio of × 10 of 5 6.1 has 11 1.04 A owing river has an intensity ratio of liter. 3100 000 . b Find the hydroxide ion concentration in an c aqueous solution that has a pOH of A rocket launching has an intensity ratio 2.3. 16 8.2 Reect and How have you Give specic × 10 discuss explored the statement of inquiry? examples. Statement of Inquiry: Generalizing relationships and changes that can in quantity model helps duration, establish frequency variability. E6.1 Ideal work for lumberjacks 12 3 of Slices E7.1 of Global context: Objectives ● Drawing cosines ● and and Converting SPIHSNOITA LER ● Using ● Solving the pi Inquiry using the tangents angles radian unit of between formula problems circle to nd sines, degrees for involving What is a ● the and of sin θ length angular and and time What is the ● How radian? cos θ, unit circle? radians of and an arc are the trigonometric related to the unit Which parameter functions circle? linear C graphs space questions ● ● Drawing in F angles displacement ● Orientation where θ is translation of a aects the sinusoidal horizontal function? in ● What is the dierence between phase radians shift ● Describing transformed trigonometric the form f ( x ) = a sin ( bx - c ) + d D shift? the order matter How do we on dene when you sinusoidal ‘where’ perform functions? and ‘when’ ? Critical-thinking Gather and Statement organize of Generalizing in Does transformations ● ATL horizontal functions ● of and space can relevant information to formulate an argument Inquiry: and help applying dene relationships ‘where’ and between measurements E7 1 ‘when’. E9 2 E11 1 12 4 G E O M E T R Y Y ou ● should nd exact ratios ● draw of ● values 30°, the cosine already of 60° of how trigonometric and graphs know 1 sine a and 2 exact on 3 a sin x a Find functions b = the 2 length tan 60° of an arc 4 a the the graph Find of and graph of sin 2x. graph the c cos x amplitude Describe the nd of : cos 45° b frequency y ● value b for values of x between 0° and 360° transformations sinusoidal the sin 30° Sketch the graph of these functions functions describe T R I G O N O M E T R Y to: Find 45° A N D of the of y = transformations y 3 = cos x cos x + to get on the 1. circumference of this circle. b Find the length of arc AB A B 60° 12 cm O Radian F Until measure ● What is a ● What is the ● How now, you are have in units measured in dierent Another unit of as the unit circle radian? unit the circle? trigonometric measured measured and varied units. as angles functions in degrees. kilometers, Exploration measurement for 1 miles related Like and angle is the the unit distances, light investigates to years, radian gradian, circle? which angles measure also known can can for be also be angles. as You do know the grad. One grad is equal to of one revolution. The French the name replace of the Objective In the describe B: a temperature general in of scale. honour of a grad, Hence, Swedish but the the term term was Celsius astronomer also was Anders used gradians. as adopted Celsius Investigating 1, as to who look rule to patter ns general for r ules patterns describe the in consistent the central with angle ndings and length of the arc, and pattern. E7.1 Slices of pi to work scale. patter ns Exploration write one-hundredth Centigrade, proposed ii. means need to term with centigrade not how 12 5 Exploration ATL 1 A unit circle 2 circle has interms Copy and circle with Central 1 a of radius complete dierent angle of 1 unit. Find the circumference of a unit π this table sized with angles, the in lengths terms of in of the Length Fraction of arcs of the unit π of circle degrees corresponding arc 360° 1 2π (circumference) 180° 90° 60° 45° 30° The lengths of rstcolumn. a 3 Suggest 4 Consider a this with table the So formula Central arcs 360° circle the radian , convert with the angle to are = radius lengths in of an r, angle as the Central measures and so of a° to shown to the arc s of this of the angles in the on. radians. right. circle angle in Copy terms Length and of r complete and of : s θ r degrees 360° in radians corresponding arc s (circumference) 180° 90° 60° 45° 30° 5 Suggest a formula theangle 6 By 8 radius Suggest 12 6 a the of for your arc length s of a circle with radius r when formula in step 5, explain why radians are a units. central the the radians. without Determine the in considering measure 7 is angle, in radians, of an arc equal circle. denition for the radian E7 Measurement measure of an angle. in length to G E O M E T R Y A 1 radian radian is is a unit the for angle measuring at the A N D T R I G O N O M E T R Y angles. center of an arc with s length equal to the radius of the circle. θ and r 360° 1° = 2π = radians radians Practice 1 Convert a these angles 10° f 2 1 b 72° Convert g these radians. 15° c 126° angles π to 18° h to 3π 5π 40° j 300° 3π 7π e 5 4π 8 5π h 5π i 12 Problem e d 4 g 9 225° c 3 8π i 150° 2π 6 f 36° degrees. b a d j 3 3 4 solving 2 πr 3 The area of a sector of a circle is given by A θ = where the angle is 360° measured You of use rotations. and An angular one radians the of Angular formula turn of s 360° revolutions second tip work displacement Example The to Rewrite = displacement full complete degrees. The angular than 5 can in the out rθ the links (angle greater = 2π . formula distance the of linear a 2π an wheel for means example, angle measured has moved displacement rotation) than For for an a wheel that the angle s in in a number (distance of radius wheel of 10π is radians. travelled) r. rotates more equivalent to (turns). 1 hand the on second a clock hand displacement for is (the 1 20 cm long. distance second is: the Find the second linear hand Find displacement travels) the in angular Find 6 of seconds. displacement the Continued angular on next each second displacement (in for 6 radians). seconds. page E7.1 Slices of pi 12 7 r = 20 cm cm cm Practice 1 The (3 s.f.) 2 hour hand is 15 cm long. the linear displacement of the tip of the hour hand in 4 hours, to 3 s.f. b Find the linear displacement of the tip of the hour hand in 9 hours, to 3 s.f. The A a 20 b how Give The Tour diameter 70 cm. wheel A wind tip A a of de Find hand is 15π cm . Find how many meters your in bike the accurate a the the to 3500 wheels minimum entire distance diameter odometer answer kilometers is has to 3 as the wheels cm. measures accurate odometer 3 travelled 62 when the wheel makes s.f. measures after 150 rotations. s.f. km used bike in number race. the of completed race The rotations race, rules must to a the be specify between Tour de nearest that 55 the cm France and bike hundred. solving blade Giveyour the blade rotates travels horse-drawn Find linear road bike the makes Determine b the a France the turbine the measures answer of Problem hour Give many your the of many rotations. Find c wheel how of passed. odometer The Find displacement have bicycle rotate. solving linear hours 4 clock Find c 3 a a Problem 2 on 18.85 carriage the linear in m. has angular answer through a Find wheel 90° the of in 3 seconds. length of diameter displacement of the the 3 During blade, that accurate time, to 2 the d.p. m. wheel in 15.25 rotations. radians. displacement of the wheel, to the nearest tenth of a meter. 90° The unit with its circle center The axes The section part of is at divide at a circle the the the of origin circle top of radius of into page the four 129 1 unit graph. 2nd 1st quadrant quadrant quadrants shows the θ 180° is a the radius unit circle ofthe in circle, the and rst quadrant. thus has 0° OP length 1. 3rd 4th quadrant quadrant 270° 12 8 E7 Measurement G E O M E T R Y A N D T R I G O N O M E T R Y y In the right-angled triangle OPQ : 1 PQ sin θ PQ = = = OP OQ cos θ so PQ = sin P = OQ , so = OQ = cos 1 PQ = (cos θ, sin θ ) OQ = OP tan θ PQ , 1 y = OQ x θ Since of P PQ is has y coordinates and the (x, length y), of the OQ O length is x Q 1 x Therefore: y sin = y cos = tan θ x = x The coordinates ofthe unit circle Reect This of the are and diagram point P (x therefore discuss shows the full y) in the 1st quadrant (cos θ , sinθ ) 1 unit 90° circle. y Point P is in the 1st quadrant. 1 P P Point in P the 2nd quadrant 2 is (cos θ, sin θ ) 1 2 the reection of P in the y-axis. 1 θ Point P in the 3rd quadrant is 0° 180° 3 x the reection of P in the x-axis. 2 Point P in the 4th quadrant is 4 P P 3 the reection of P in the 4 x-axis. 1 ● What P 2 ● P are the and 3 P coordinates points 270° 4 What conclusions ratios in the graph protractor paper, to can dierent Exploration On of ? you make about the signs of the sine and cosine quadrants? 2 draw draw a quarter angles of 0°, circle 15°, with 30°, radius 45°, 60°, 10 cm. 75° Use and your 90° as shown. y 90° 75° 10 60° 8 45° 6 nis 30° 4 15° 2 0° x 0 2 4 6 8 10 Continued on next page E7.1 Slices of pi 12 9 1 For each 2 Copy angle, and read complete θ in the this values table θ in degrees of of cos and sin from the graph. values. radians 0 using π sin θ cos θ 0 1 0 15 30 … 90 3 4 Compare etc. Predict the 105°, 5 your sin 30°, Repeat 4th values Explain values 120°, step 4 Reect of 135°, for quadrant: the = and with why sine 3rd calculator may and 150°, 285°, the they be cosine 165° for and discuss …, angles 180°. = quadrant: 300°, values for sin 0°, sin 15°, dierent. in Check 195°, the 2nd with 210°, …, quadrant: your 270° calculator. and the 360°. 2 π ● Use this sin = unit circle to explain 2 why: sin 5π π 6 6 30° sin = π -sin 0 7π 11π sin ● = Do you The your 6 results made trig 6 -sin in functions cotangent can conrm the Exploration secant, also be conclusions 2? cosecant found 3π 2 Explain. on and the U R unit circle. θ T Pick a point P in the rst quadrant and extend P the line enough is segment for labelled = 1 it to RU line x line segment OP and intersect here. from up the Then point S, to the line draw right, y = the upward to 1 far which tangent meet the θ OU and label this point T S O Then OT 13 0 represents sec , OU is csc E7 Measurement and RUis cot Q . G E O M E T R Y Example Write down these values without b = T R I G O N O M E T R Y 2 a a A N D using a calculator. c Convert the degrees so radian measure to 120° you can draw it easily. y 1 √3 2 2 1 Draw the Make a angle in the correct quadrant. √3 right-angled triangle with the 2 x-axis and label the lengths of the sides. 120° 60° x 1 2 = cos 120° = or b = the x-coordinate. 90° Convert the radian measure to degrees. y (0, 1) Draw the angle on the unit circle. 90° A point on the unit circle has coordinates (cos θ, sin θ). x So = c π = sin 90° = the value of sin θ is the y-coordinate on the unit circle. 1 180° Convert the radian measure to degrees. y 180° ( 1, 0) Draw the angle on the unit circle. x On the unit E7.1 Slices of pi circle, tan θ 13 1 = Reect ● When and you always ● If you To nd ● the draw angles 3 in the unit circle, why is the hypotenuse value positive? drew theother How discuss a circle sides does of that the ratios triangles radius triangle compare trigonometric special with and to of = be? the 2 for What value angles Example in would four part the calculated the 2 a, what x-coordinate in Example quadrants, you 2 would be? part can a? use: SOHCAHTOA 30° 45° √ √ 2 2 3 1 60° 45° 1 1 ● similar special triangles Thiscorresponds to the where unit the hypotenuse is equal to one unit. circle. 30° √ 3 1 45° 1 1 2 √ 2 60° 45° 1 √ Practice 1 Write down these values. π sin b tan 2π g 2π cos 3 f 2 2 3 π a 1 c d 3 5π 11π h sin 2 Find two 3π cos e cos 6 2 3π cos i tan 6 4 Problem 5π tan 4 4 solving angles that have the given trigonometric ratio, 0 < A ≤ 2π If 1 a tan A = -1 b cos A the = c sin A = given - 2 give cos A = 0 e sin A i Write π a down cos π coordinate = 5π d 4 2π The on unit the 13 2 circle unit has equation 11π 11π circle. E7 Measurement , sin 6 x 3 cos point. , sin 2 ii each 3 , sin 4 for 2π cos b 6 5π cos values , sin 6 c the 6 2 + y = the radians. 2 3 in is radians, 2 3 d domain 2 1. Show that these four points are answer in G E O M E T R Y Reect ● Can ● How than To the and an can 0 or answer unit angle Write measure you nd more the circle Example discuss the questions you drew sine than and ? Can cosine an values angle of measure angles that less than measure 0 ? less ? in in Example Practice 3, 3, you could question also use the results from 3 3 down these values a without b a T R I G O N O M E T R Y 4 more than A N D = using a calculator. c cos 495° Convert the radian measure to degrees. y ( 1, 1) One √ rotation 360°, so 495° is one rotation plus 135° more. 2 135° 1 Draw x 1 the = = cos 495° an angle x-axis sides b is in and the of 135°. label special Make the a right-angled angles. triangle Label with the angles triangle lengths 90°, 45°, of with the 45° = sin 990° y Two is complete 270°more. rotations Draw an is 720°. angle of So 990° 270° 270° x The (0, = sin 990° value of is the y-coordinate on the unit circle. 1) = -1 Continued on next page E7.1 Slices of pi 13 3 c y Negative angles start at zero degrees and rotate clockwise. 1 Draw 150° clockwise from zero. Make a right-angled x √ 3 triangle 2 with the x-axis. This is one 150° = Practice 1 Write down a 8π b 3π 13π Write tan ( 3π ) 7π down a negative angle (in 4 radians) π 6 has the given π 3 cos that i 6 sin f sin h 7π 4 tan 2 tan c e 4 9π cos cos 2 values. 3 g these sin d 4 trigonometric ratio. 1 a tan A = 1 b cos A c = sin A = -1 2 3 d cos A = 0 e sin A = 2 Graphs of sinusoidal functions C ● Which parameter aects the horizontal translation of a sinusoidal function? ● What is Exploration 1 Graph of 2 axes the 13 4 dierence write the between phase shift and horizontal shift? 3 functions and Describe the f ( x ) down = the sin ( x ) and relationship transformation on E7 Measurement the on between graph of f these that two gives the same set functions. the graph of g of the special triangles. G E O M E T R Y π The graph of y = cos T R I G O N O M E T R Y x is A N D 2 a horizontal translation of the graph y = cos x π by units in the positive x-direction. 2 y y y y = 2 2 2 3π π x 0 x π π π 3π sin x 1 0 2π = sin x 1 3π 2π 2π π 3π π 2 2 2 2 π π 2 1 1 y = 2π π y cos x = x − 2 The graphs of y = a cos bx and π So the graph of y = cos x y = a has 2 have amplitude a and frequency b. - sin bx amplitude 1, frequency b = 1, and is translated π horizontally by units in the positive x-direction. For sinusoidal functions, 2 when The y = the four a cos parameter b parameters ( bx - c = of 1, a ) + d are the horizontal sinusoidal interpreted translation function y graphically = is a sin called ( bx - c the phase shift ) + d or as: b y a d x c Exploration 1 Plot the graphs horizontal 2 g Plot graphs the Rewrite Using a in = your a y = a the ( x ) form of the f y = a y = on cos b (x sin = on 2x the g ( x ) ( x ) = sin (b x + + g ( x ) graph of sin 2(x cos g ( x ) graph steps + 1 d of f + and into ( x ) sin that . gives Write the down graph of the g ( x ). ). and the c) f = = ( x ) cos that . gives Write the down graph of the g ( x ). ). 2: an equivalent function of the form d cos (b x ) and (x from ) a = form results sin b (x convert f translation in convert y b g of translation Rewrite horizontal 3 4 c) + d into an equivalent function of the form d E7.1 Slices of pi 13 5 The values sinusoidal For ● ● of b and c both inuence the horizontal = functions 1, the y = a sin (b x When c > 0, the shift is in the positive When c < 0, the shift is in the negative shift is the equal to c is + b horizontal parameter c) When called actual graphs of = a cos (b x c) + d : shift to the to right. the translation left. of the graph, . shift is in the positive When < 0, the shift is in the negative window phase horizontal the the y x-direction, 0, x-direction, to x-direction, the to right. the left. 4 amplitude, translation and x-direction, > Example d the When State of functions. sinusoidal The translation of from y = 0 - 2 to frequency, sin (2x period, π) 4. horizontal Draw the shift graph and of the vertical function using a 2π In : |a| y amplitude is |a| = is the amplitude 2 2 b frequency is b = is the frequency 2 0 π π 3π 2π 2 2 2 period is is the period. 4 6 y = −2 sin(2x − π) − 4 horizontal shift is 8 is the horizontal shift. vertical translation is d = - 4 d Example Without On the using frequency horizontal vertical = = a set GDC, of vertical draw axes, use the graph of the transformations function to draw y = the sin x, graph from translation. 0 to 2π of Find the shift and amplitude, frequency, 1.5 vertical 2 shift = translation = -2 Continued 13 6 the 5 same amplitude is E7 Measurement on next page translation. horizontal G E O M E T R Y A N D Rearrange y = so T R I G O N O M E T R Y that x is ‘on its own’. 1.5 Work Step 1: Compare y = sin x with outward from x : y 2 π y = y sin x = x 1 The 2 graph of is a horizontal 0 x π π 3π translation of x-direction of units in the positive 2π 1 2 2 the original function y = sin x 2 Step 2: Compare y = sin with : y 2 π y = The x graph of is a horizontal 2 1 dilation of , scale factor . 0 x π π π 2π The 1 2 frequency tells you the number of 2 y = sin(2x − π) complete sine curve cycles in the period 2π 2 Step 3: Compare y = sin 2 with y = 1.5 sin 2 : y 2 y = 1.5 sin(2x − π) 1 0 Redraw with amplitude 1.5. x π π 3π 2π 1 2 y = 2 sin(2x − π) 2 Step 4: Compare y = 1.5 sin 2 with y = 1.5 sin 2 2: y 2 y = 1.5 sin(2x − π ) 1 0 Redraw, translated 2 units down. x π π 3π 2π 1 2 2 2 3 y 4 ATL = 1.5 Practice 1 State the vertical a y c y sin(2x − π) 5 amplitude, translation = 0.5 sin π 2x π x + 7 4 = - sin 3 period, phase or horizontal shift, and b y = sin(3 x d y = 6 - π ) + 2 - y frequency, of : = 3 cos 4 x e 2 cos (3 x + π ) - 3 - + 2 3 E7.1 Slices of pi 13 7 2 Without using π a y = cos x (4 x b y = c y = 3 sin d y = 0.5 sin The draw the graph of each function: + 3, 2 from 0 to 2π - 2π ) - 1, ( 0.5 x ) - 2 , Problem 3 GDC, - cos a (2x from from 0 0 to ) - 2, from - π π to 6π 0 to 2π solving function y = a sin ( bx - c ) + d has amplitude = 2, period π , = horizontal π shift = to the right, and vertical shift = -1. Write the equation of the function. 4 4 For each graph, equivalent of f ( x ) = nd forms: cos x. i as the a Verify equation of the transformation that your two of sinusoidal f ( x ) answers y a = sin are functions x, and ii as equivalent in a two transformation using technology. y b 10 4 9 8 2 7 6 5 0 5π 3π x π 3π π 5π 4 2 3 2 4 1 x 0 π c d y 2π 3π 4π y 10 x 0 π π 3π 1 2 8 3 6 5 4 7 2 9 π 0 x π 2π 3π 4π 4 15 13 8 E7 Measurement 2 2π G E O M E T R Y Reect ● In and Practice functions Some periodic sinusoidal a can seaside be where is of 4, 5 for sine, which and phenomena, in graphs which such as was in it easier terms tides, can of be to nd cosine? the Explain. modelled using 6 town, the a Draw b State c Explain a natural modelled t question terms T R I G O N O M E T R Y functions. Example In 5 in discuss A N D the the the by the number graph values what depth of the (in meters) sinusoidal of of d hours the the water over the course of a day , midnight. amplitude, you the function after sinusoidal values of function. period, found in b horizontal shift and vertical shift. represent. d d(t) = 1.6 sin(0.5 t + 0.47) + 1.93 4 Draw the graph for 24 hours, 3 for values of t from 0 to 24. 2 1 0 t 4 b amplitude period 8 = 12 16 20 24 1.6 Find the values from the function. = horizontal vertical shift shift = = 1.93 Explain what these values mean c in depth The full over period cycle 24 vertical The horizontal the , high The above context of the tides. hours. is of the shift or is low the shift mean about and 24 hours, and is the time taken for a tide. mean means at depth over midnight the the 24 hours. water depth was already value. E7.1 Slices of pi 13 9 Practice 1 A buoy 6 bobs thebuoy in up π t b State the shift. Explain the The the (in water with seconds) can the be waves. The modelled of values the of model to i 2 seconds ii 5 seconds. amplitude, these nd period, represent the height in of the the horizontal context buoy of shift the force of the sun and moon cause changes 3 a Draw can b State the a be modelled number graph the values c Find the d Explain height of of the amplitude, their The by the function in this height why h in hours since ride begins midnight and h is the a Draw b State c 4 diameter of period, the be the the tide of vertical at Find the 10 lasts in a height of of amusement The ride seconds, 32 Ferris this the seconds. high particular by wheel height and and car the is horizontal low on a tides giant function 172 period, by the the car ride 7 then after m can shifts, 5 Draw b Interpret The table a function graph the of this h the and of the and will occur Ferris is wheel interpret t so important. minutes 2π h (t ) = 86 sin horizontal the of average each for be modelled ground. descends car after (t - 7.5) + 94 30 shifts, and interpret using car along meters - 3π a a sinusoidal travels track. after t horizontally The seconds entire can ride be + 7 4 from 10 parameter monthly A t t in π h (t ) = 3 cos function meaning shows and minutes. also above climbs height 10 a meters. m. vertical modelled in function. park The + 0.67 , context. starts and + 3) midnight. when modelled amplitude, values function. for graph their Another the of context. meters of heights (t 6 The the function. predicting can in h (t ) = 1.3 sin the vertical π is and problem. after: t of function solving which where h the function. the what gravitational tides height by graph Problem in t 2 Draw Use time + 5 a c the down at π h (t ) = 1.5 sin 2 and meters in to 32 the temperatures seconds. function in in this Fahrenheit context. for a US city. Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 32° 35° 44° 53° 63° 73° 77° 76° 69° 57° 47° 37° 14 0 E7 Measurement G E O M E T R Y a Draw a graph months, b Use and c the and data to interpret Write the ● Does nd their of the How Reect ● Write do and down data, the Now draw in function matter order in dene b Describe graph c a the in b a 4 Summarize f give the vertical and horizontal shifts, this problem. perform transformations on and ‘when’? used, in order, to draw you the graph of 5. are used. always Try get a the changing few the dierent same graph as in on the graph of y = cos x on the graph of y = sin x the graph of y = cos x that give the transformations that give the 3. the transformations on that give the . steps the the . function 1 in step 1 by applying the two transformations order. or and your transformations to Do transformations whether Repeat represent 5 the each 3 to Explain. dierent State you transformations of Graph models Example of Describe graph 2 of period, by 5? graph x-axis of Example Describe the 6 transformations. a on y-axis. context. when ‘where’ ordersof Exploration 1 that transformations graph which this 12 functions? discuss the to the amplitude, in ● 1 on T R I G O N O M E T R Y transformations we the using meaning order sinusoidal ● this temperatures sinusoidal Order D of the A N D not 2 for of f is these ndings need graph there by to be ( x ) = a dierence your two graphs. functions: indicating performed a in sin (bx the on c) + order the in graph which of y = sin x d E7.1 Slices of pi 141 Summary On the P ( x, unit y ) on circle, the the coordinates terminal side of of a angle point For are sinusoidal and ● : When b phase A radian is a unit for measuring angles. radian length of the is the equal angle to the at the center of an arc = 1, the parameter c is called the shift When to 1 functions the c > 0, the shift is in the positive x-direction, negative x-direction, right. with radius When circle. to the c < 0, the shift is in the left. s ● and The horizontal shift is the actual horizontal θ translation of the graph, equal to . r 360° 2π = radians c When > 0, the shift is in the positive x-direction, b 1° = radians to the right. When to Mixed 1 the these interms of angles from degrees to radians, 5 π State 12° 225° the b 240° c 288° d g 810° h 336° i 480° e 80° amplitude shift (vs) or Convert these angles from radians to π 2π 3π b j degrees. e 11π using a y = 2 c y = 0.2 sin( π x ) sin 6 y = π x -sin(6x Without using 30 a 2 3 cos b sin π c write a y e cos 13π 3π d sin 4 f 6 a b y = 3 cos (2x ) - 3, π = sin π x tan ( 4 π ) 5π 3π - 2 + 8 2 1 draw the graphs of : 2 from 0 2π to 6 - 4 , 2 from 0 to 2π 7π y = 2 cos π 0.5 x + - 3, 4 from 0 to 2π cos 4 solving sin j 6 7 Find the equation that denes each function. y a Problem π x - Problem i GDC, h = -3 cos ) an sin g tan 6 3π y -1 3 d + 2π down: c 7π = 5 cos 60 y + 12) π (4 x b j 4 calculator, (p), vertical 17π i 20 Without 23π h 5 3 π g period 12 6 7π f (f ), and of : a e 15 2 (hs), 5π d 5 12 shift 700° 8π c frequency 125° a (a), horizontal 2 x-direction, left. phase shift f 0, the shift is in the negative practice Convert a < solving 4 4 One car on a Ferris wheel rotates through an 3 angleof 120° in 11 seconds. During that time, 2 thecar travels a distance of 10.47 m. Find the 7π π radius of the Ferris wheel to the nearest cm. 1 0 31π 0 23π 0 0 12 12 12 12 x 1 2 14 2 E7 Measurement G E O M E T R Y b e y Find in the exact 2147.3 A N D distance revolutions T R I G O N O M E T R Y travelled, by in meters, a: 1 i 14″ tire ii 15″ tire iii 20″ tire x 0 π π 3π π 1 2 2 4 f 3π 2 Explain how number of the radian revolutions measure helps of you the nd the 3 4 distance travelled. 5π π 3 3 4 4 Problem solving 5 9 8 The a diameter Explain of the of why tire to a car you tire is need calculate given to in know the inches. the distance The and seal population decreases on an annually. be modelled using In early January, In early July, a iceberg The increases population trigonometric can function. diameter a car the population is 3000 seals. wheel after all the baby seals are born, travels. there b Find in the 1050 distance travelled, revolutions by in whole meters, 3000 16″ tire ii 17″ tire iii 20″ tire Draw inches to cm to 1 inch a graph the the Find of the the radian The the population following reduces to January. measure of the trigonometric population of seals function at any to time year. = 2.54 Write down of 0.6 the trigonometric equation that cm. represents c by obtain b metricdistances. seals. again represent of Convert 5000 a: a i are seals this function. c Find the seal population at the end of May. d Find the seal population at the beginning revolutions tire. of November. d Hence, in i 0.6 15″ For of is is around class, Find the when A used the travelled, in meters, a: 18″ tire a to sundial be iii to edge measure of the angle surveyor’s with made surveyor’s central the by 22″ e Find 2 on wheel the circle (in a a diameter with length of the radians) wheel rotations 3.5 a i Write The ii State what the variable State what the parameter 5 d were the rst down of iii arcs Suggest sundial. of the its arc means of State increasing the could eectively trajectory modelled where c = launches (until by 0. seals. the it a 6.25 to catapults distance stone lands on t function ( x ) t x represents. the a catapult represents. could inuence into the from it parameter b determines represents. the stone’s point The stone starts travelling when it is as and stops as soon as it hits the which State the domain and range of enemies. the air ground) ( x ) = the how rotations use neutralize function: simplied impact. t( x Acatapult the how what Explain rotations ground. they 4500 value. launched a are makes: b rotations Romans there radius v 2 month(s) school of c which tire iv a in context going playground. 20cm distance ii in science 12m the tire Review 1 nd revolutions a sin ) in terms of a and b whose can ( bx be - c ), b State what Suggest the what parameter this says c represents. about the catapult’s position. E7.1 Slices of pi 14 3 c Keeping in explained range of t mind in the part ( x ) in a trajectory iv, terms state of a, of the b the stone domain and as i and Suggest why the vertical displacement of a sine trajectory curve if the accurately starting model point of A is 10 m above the of a, equation of second rst stone is launched, State and its trajectory in this iii GDC b and this stone’s f or c otherwise, and stone’s write iv coordinates State stone the lands State at the sensitivity very the of large distances. Square to consist over and a operating hundreds scale than any of the it Hence, stone’s state revolutionize and How you of Generalizing can help or by spread (SKA) radio early and building combining over long is in access the 2020s. a of will Africa this size, radiotelescope magnitude allowing understanding It spread southern to next- astronomy, telescopes instrument of 6π better them of the to universe. discuss explored the statement of inquiry? Give specic examples. Inquiry: and dene 14 4 the facility, Reect for radio orders our either actual interferometer. Array an have is the down the modelled by the of the starting of it the is position launched. position where ground. reaches ever-greater kilometers current Statement an in of With will that have of 5π resolution by telescopes called hundreds astronomers on array Kilometre Australia. both telescopes interferometer start of an is 4π telescopes smaller This generation due from of 3π increase individual signals numbers The 2π new nd ) moment coordinates on the stone’s can is - π the maximum this applying ‘where’ relationships and ‘when’. E7 Measurement between measurements in space height, and height. domain 4 Astronomers stone’s trajectory. trajectory ( x ) = 5 sin ( 0.5 x the the where π the graph: 8 0 of is it shown range the ii A and ground? of e your function i stone Using values f the domain trajectory. the catapult’s position is ignored in this question. Does the c ii d State trajectory. and range of this Making it all add up E8.1 Global context: Scientic and technical innovation Objectives ● Finding the Inquiry sum of an arithmetic series questions ● What ● How is a series? F ● ● Finding Finding where the the sum sum of of a nite an geometric innite series geometric can rewriting easier to What are a series make it sum? series, appropriate ● between similarities real-life and arithmetic ● Can you and patterns dierences geometric evaluate a series that require series? that goes on D forever? ● What are the risks of making generalizations? ATL Communication Understand and use mathematical notation 8 1 12 1 12 2 E8 1 Statement of Inquiry: Using can dierent help forms improve to generalize products, and processes justify and patterns solutions. 14 5 MROF the C Y ou ● should work with already arithmetic know how sequences 1 to: Find the 20th nth term term of and each the arithmetic sequence. a 5, b c ● work with geometric sequences 2 9, 25, 13, 42.7, Find the 17, 22.5, 43.9, the … 20, 17.5, 45.1, next nth term two of … … terms these and geometric sequences. a 15, b c ● generate the triangular numbers 3 30, 100, 162, Write a 120, 6.25, 54, 18, rst the 5 generate explicit a sequence from an 4 formula … 2, … triangular general triangular ● 240, … down: the b 60, 25, Generate formula numbers for the numbers. the rst each sequence: a = ve terms of + u 3n n 1, ∈ , n ≥ 1 , n ≥ 1 n n b u = 3 × 2 + , n ∈ n Series F A ● What ● How sequence sequence. is an The is a series? can rewriting ordered sequence list and a of series make numbers. the series A it easier series below have is a to the sum? sum nite of the number terms of of a terms. In MYP Mathematics 1, 7, 4, 11, 2, 4 4 11 is a sequence, even though there is no pattern in it. Standard 1 + 7 + + sequence. In + 2 this + -4 case, is a the series, sum is because it is the sum of the terms of saw a do 21. that not follow An A arithmetic geometric series series is Exploration 1 1 of Find the value is the each a 1 + 3 + 5 + 7 + 9 b 7 + 7 + 7 + 7 + 7 c 1 + 4 + 9 + 16 d 7 + 14 28 + + the sum sum of of the the terms terms of of a an arithmetic geometric sequence. sequence. series. + 11 + 25 + 56 + 36 112 + 224 Continued 14 6 E8 Patterns on next page 8.1 have a you sequences to pattern. A LG E B R A 2 Look at the a Which b One is patterns are The neither terms of the arithmetic description 3 in series? geometric of a series nor in step Which 1 are geometric arithmetic. Suggest series? a suitable it. series are given by the formula u = 4n = 3 2. n Find the value of the series u + u 1 + u 2 + u 3 + u 4 5 n 4 The terms of a series are given by the formula u × 4 n Find the value of the series u + u 1 S means the sum of the rst + u 2 n + u 3 terms 4 of a series. n For example, S = u 4 + u 1 + u 2 + u 3 4 2 ATL 5 Given that u = n 2n, nd the value of S n of Some In the types Practice triangular , the sum of the rst 6 terms 6 series. of 6 series of have MYP numbers special Standard formulae 8.1 you that saw help that you the nd general the sum formula easily. for the is: n S ( n + 1) = n 2 The nth pattern triangular with n number is the T = 1 T 1 Since each number so the of nth number of dots needed to make a triangular rows: triangle dots in is made the triangular = 3 T 2 nth of rows triangle number is = 6 T 3 which can the be same get longer found as = 10 4 the by by one adding sum of 1 the every + 2 rst + n time, 3 + 4 … + n, integers. 5 ( 5 + 1) Using the formula, the sum of the rst ve positive integers is S the + 5 × 6 = = = 15, 5 2 which you can Example ATL Find 47 + the 48 easily by adding 1 + 2 + 3 + 4 + 49 + of the … + series 47 + 48 + 49 + … + 82. 82 Sum = S 82 2 5. 1 total + check S sum 46 the of series the S 1 + series 1 2 + + 2 … + + … 82, + and from it subtract the 46: = 1 + 2 + 3 + 4 + …. + 46 + 47 + 48 + 49 + … + 82 = 1 + 2 + 3 + 4 + …. + 82 = = 2322 S 46 46 S 82 S = 47 + 48 + 49 + … + 46 E8.1 Making it all add up 14 7 82 The sum S of the rst n consecutive positive integers is . ATL You can use to n You can also S use nd the total of any series of consecutive integers. ( n + 1) = to nd the sum of any series of integers with a n 2 common factor, Example Find the 5 + = 5(1 + + 15 2 shown in Example 2. 2 value 10 as + of + 3 the … + series + … 5 + 10 + 15 + … + 725. 725 + The common factor is 5. 145) = = 52 925 Practice 1 1 Find the total of the series 2 Find the value of 25 3 Find the value of 4 4 Find the value of 180 + 26 1 + + 2 27 + + 3 + … 4 + + … + 30. 53. In + 8 + 12 + 16 + 182 + 184 … + a Problem 5 6 7 Find b Hence value a Find the value of b Find the value of c Hence nd nd terms + 186 + 188 + 190 + … + 324. solving a The the + of a the the of the value 1 2 of series + 2 3 + value series series + 5 -4 of are the + + 7 4 + -6 1 given + 2 6 1 9 + + by + + -8 3 - the + + 8 + … + 5 … + 101. … + + + + 3 + 4 7 60. + + … + 59. -100. … 100 formula 9 = u + 3n 101. + 7. n Find the value of S 5 n 2 8 The sum of the rst n squared numbers 1 + 4 + 9 + … + n ( n + 1) ( 2n + 1) = 6 a Use this formula Exploration 1 to step conrm your answer Find the value of 1 + 4 + 9 + 16 + … c Find the value of 1 + 4 + 9 + … + 400. d Hence 14 8 the to 1 + 4 + 9 1c b nd value of 121 E8 Patterns + 144 + 3 and 4, take out 128. + 100. 169 + … + 400. + 16 + 25 + 36 in common factor. A LG E B R A Problem 9 Find the solving value of Exploration 1 a Copy and 1 – 4 + 9 16 + … + 361. 2 complete 40 – + 44 the + 48 48 S = 40 + 44 + S = 72 + 68 + calculations + 52 + 52 + 56 + 56 + 60 + 60 to nd + 64 + 64 the + 68 + 68 value + of: 72 + 72 + 40 The + + + + + + sum 2S = 112 + + + + + + + line + terms in are reverse b Hence nd c Deduce the value of 2 Use a similar a 57 + b 1.7 c 30 + + Check 2.9 21 Do ● Without This you S have himself + 3 + the + -6 + to + out series Gauss it, sense is of and for his + + rst line. 93 7.7 + + + of: 99 8.9 + + 105 + 111 10.1 -24 the seven to the numbers terms, called terms: have 5 task if how 9 + when from probably the + the 1 to you had + as his to twice could to nd nd 2S 2S ? and 29 it is the teacher 100. already he series … method, used numbers set in explain Gauss’s teacher to value calculator. all said all him a the with sometimes sum the 1 out all 87 -15 using write the 6.5 discuss this is nd 81 5.3 order asked Gauss knew work it method was – out it that him not the wouldn’t the total slowly. Practice Find + the the S to + answers discover made 75 4.1 12 Karl calculate + writing method rstto + need for 8-year-old to 69 + of method and ● then + your Reect 1 63 value just of the second 2S in the in the the 2 value of these arithmetic series: a 23 + 30 + 37 + 44 + 51 + 58 + 65 + 72 + 79 b 30 + 28 + 26 + 24 + 22 + 20 + 18 + 16 + 14 c 24 + 28.4 + 32.8 + 37.2 + 41.6 + 46 + 50.4 + 54.8 + 59.2 + 63.6 E8.1 Making it all add up 14 9 2 3 An arithmetic a Find the b Hence Consider 40th nd the a Write b Hence c Find Find 5 An the the the sum Use sum of + = S the of begins from has 40 terms. =15 rst terms + 19 + term in … and the + 199. the common dierence. series. + 25 + + 21 series 48 + + … + 104. … could 2 to nd u + … + have. the sum u 2 + of u u ) + (u n + + the arithmetic + u 1 n u + u 2 u ) n why … 1 2 clearly + n n 1 Explain + the Exploration + + 29 that 41 u n (u series n u n a of 1 = and series. series value … u n 2S … series. 2 = S + 3 + n + 19 arithmetic series u 1 S the the method u + the number maximum the series of value of Exploration 1 6 solving arithmetic Find ATL the sum arithmetic nd the begins term. the down Problem 4 series + … + (u 1 + (u + n u 1 ) and (u n 1 u 1 + ) + (u 2 u 2 ) n + u n are ) 1 equal in value. 1 You b Hence explain why 2S = n(u n c Write down a formula + u 1 for S in useful terms of n, u n and Use the formula for the nth term u = a + (n 1)d to general u 1 nd use formula to write down a the nth term: formula n u = n for S for an arithmetic series with n terms, rst term a and common n dierence d. Give Reect and How you have Exploration For an 2 formula discuss used to your the concept series terms of a, d and n only. 2 Exploration arithmetic in with of generalization when moving from 3? rst term u = a and common dierence d, 1 the formula for the sum where of u the is rst the n nth terms term, is given by: 3 4 or n Learn both useful for 15 0 of these dierent two types formulas. of Examples problems. E8 Patterns it the n for 2 might ) n and show they are both a + (n 1)d A LG E B R A Example Find a = the 3 value 15, d = 2 of the and n arithmetic = series with 11 terms that begins 15 u = the 22, u = of the 78, n = arithmetic series with 9 terms: = Find the when you know a, d and n rst term 22, last term terms, and n 78. 9 this formula when total 5 + 8 + 11 b 1.4 + 2 + c 15 + 29 d 57 + 52 Find the of + these 14 + arithmetic know the rst and last 17 + 2.6 + 3.2 + 43 + … + 141 + 47 + … + -3 sum + 20 3.8 + + 23 4.4 series. + + 26 5 + + 29 5.6 + + 32 6.2 + 6.8 + 7.4 + an arithmetic series with 15 terms, rst term 20 b an arithmetic series with 18 terms, rst term 6 and last c an arithmetic series with 11 terms, rst term 9 and second d an arithmetic series with 32 terms, second e an arithmetic Find Find value the the which series with common and term dierence 12, 16 common and rst term 5 43 term fourth term dierence 39 15 term and 22 last 291. the and 8 of: a 18 you 3 a term 4 formula 450 Practice 3 this 9 Use 2 ... 4 value 1 1 + 275 Example Find 17 11 Use = + last value has 11 of the term of arithmetic is the series with series that 12 terms, where the rst term is 102. arithmetic begins 17, 19.2, 21.4, … and terms. E8.1 Making it all add up 1 51 Problem 5 Find 42 6 the and An solving sum the of the arithmetic eleventh arithmetic term sequence is series with has x terms + x 1 Find the value of x 15 terms, where the eighth term is 57. + x 2 + ... + x 3 = 726. 55 . 28 Exploration You it have seen backwards approach 1 Try S = to to 1 + 3 3 Copy S = 3S = 1 + = S = 1 2S = -1 Hence 5 Explain 6 2 Use the + + 27 + + 27 + b 2.5 + c 1 1.3 d 625 9 + 27 + + 9 + 27 + 6 b 2500 c 160 was 32 + the + the + try to rst use writing the same + value 2187 + of the series: 6561 method. of 243 you by sequence? the 729 values + 3S: 729 + + 2187 + + 6561 + + 19 683 subtraction: + 81 of + + 243 2S, useful by, + + pattern and to and 128 always + + + + from 126 90 + + 1.69 + value 48 15 2 + nd series + 729 + + 2187 + + 19 683 6561 ... series will + 15 + + value it this 8 0 the why 42 the + + 500 a the 3 + to + 3 method 14 Find complete when geometric 243 81 arithmetic happens a with the 9 0 + an deduce multiply check 512 + behind work by that 2048 + the 3. your of Suggest S what suggestion you should works: 8192 geometric when value trying to sequences sum a means geometric that this sequence. 4 a + 81 9 approach 1 + problems why Explain 27 of method + + Practice + sum What sum + nd 2 2S. the 3 + multiply = 9 can 3 + 4 nd complete and 3S you Gauss’s the and Copy S to + Describe 2 that nd use 4 378 540 + these + 3072 1500 + 900 + + 360 1134 3240 320 384 240 + 2.197 400 of Exploration + + + + + 256 24 576 540 540 + + E8 Patterns + + the 10 206 3.71293 204.8 + 324 810 nd value + of these 30 618 + geometric 91 854 + + + + 4.826809 163.84 series. 196 608 + 194.4 1215 + + 1 572 864 + 116.64 1822.5 + series. 275 562 19 440 2.8561 + to 3402 geometric + 4 6.2748517 A LG E B R A 3 A geometric a Write b Hence series down nd an the begins 2 + 6 expression value of S + for , 18 + the the 54 nth sum + …. term of the of the rst 8 series. terms of the series. 8 Exploration A 1 geometric Write 5 series down has rst term expressions in a and terms common of a and r ratio for u , r u 1 second, 2 Let S third be the and nth sum of , u 2 and u 3 (the rst, n terms). the rst n terms. n n Apply the method in Exploration 4 to show that (r 1)S = a(r 1). n 3 Hence write down a formula for S in terms of a, r and n n 4 Use your a a geometric series with rst b a geometric series with nine c a geometric series with seven term 5 For the 1000 6 + geometric 800 write b show c explain Show and a + 640 down that the clearly when the geometric a of: term 3, terms, term geometric seventh 409.6 of the common rst terms, term second ratio 12 7 and term and eight second 168 and terms term 18 third sum in + 327.68 rst term + 262.144 and the common ratio gives: negative fraction above series ratio geometric second c sums numbers formula this can formula have be come from. rearranged will have a to give: positive numerator denominator. a a the formula the formula common + value the that positive 512 sum where either b nd series: + the Use a to 504. a State 7 formula of is rst the term value 16, of: seven terms in total, and a with ten terms whose rst term is 20 and whose 10 series term nd 0.4 series is with to with twenty terms whose fourth term is 7 and 56. E8.1 Making it all add up 15 3 You saw in very dierently geometric MYP Standard depending series, and you Mathematics on whether will explore or 12.2 not this in that 1 < the geometric r < 1. n 1 thebiggest dierence is that it is easier to S use The debatable sequences same is section. behave true For for now, r = a when 1 < r < 1. n For a geometric The rst The second version Reect ● What How and Example 10 a + the 5 = + 10, ratio would easier is rst to use easier if use a when use r and > 1 when common or 1 r < < r ratio r : -1. < 1. 3 the formula for a geometric series with 1? you ratio you to term r is nd the sum of a geometric series for which the 1? 5 sum 2.5 r with discuss happens common Find is version common ● series 1 of + the rst 13 terms of the geometric series which begins ... = and n = 13 1 = 20.0 (3 1 Choose most suitable formula a a geometric series with rst b a geometric series with ten c a geometric series with twenty 15 4 to a sensible 5 the r < 1 s.f.) Round Practice < E8 Patterns to term nd 16, terms, the value seven rst terms, of : terms term 20 fourth and and term 7 common second and ratio term seventh 0.4 10 term 56. degree of accuracy. A LG E B R A 2 Find the a 5 + b 7 c 96 25 3 3 + + the Find + + 6 of 3125 7 + 7 216 value geometric 625 + 7 + term the each 5 + 7 144 second of 125 4 + 7 Find 4 total + + 8 15 625 9 + 7 324 + 7 + series. 486 10 + 7 + 729 the geometric series with of the geometric series that of the geometric series with ten terms, rst term 24 and 96. value begins 18 + 24 + … and has eightterms. 5 Find the andlast value term 430 467 rst term 10, common ratio 9 210. Tip 6 A geometric series has rst term 14 are two possible and third term 56. In a Show that there values for the common 8, how b 7 Hence A nd geometric two possible series has rst sums term of 15 the and rst seven second terms term of 10. the series. the rst eight you use Find the (E7.3), they help might sum to nd this A terms If in not, solving geometric series is formed by summing the integer powers of can number 2: using S of series. you 8 the terms. number Problem know logarithms you of if to ratio. nd of trial the terms and error = 1 + 2 + 4 + ... n and Determine the least number of terms so S that > 1 your GDC. 000 000 000. n Series C ● What that There are many arithmetic or appropriate in are real-life the arithmetic real-life situations geometric to similarities require use an series. In arithmetic and and where each or dierences geometric problems worked geometric between real-life patterns series? can be example, solved using consider why it Arithmetic is and sequence. geometric sequences Example 6 life explored A company month of the to launches subscribe. year, another a Explain why b Find c Assuming the service the income in no the a In new the 500 music rst customers monthly in the rst join income rst customers streaming month, 1200 every forms service. Customers customers sign up. pay For $4 the in contexts in real- are MYP Mathematics per Standard rest 12.2. month. an arithmetic sequence. month. leave the service, nd the total income from the year. Each month the income increases a by so b this 1200 × forms 4 = an arithmetic 500 × $4 = $2000. series. $4800 Continued on next page E8.1 Making it all add up 15 5 c a = 4800, d = $2000 and n = 12 Use S = (2 × 4800 + 11 × this formula when the last term is unknown. 2000) 12 = $189 600 Example A social Remember In the rst a Explain write the units. 7 networking thenumber to of new month why site gains members of the 2016 the number new is site of members 1.5 times gains new the very quickly. number 15 000 members new per in Each the month, previous month. members. month forms a geometric sequence. b Find the number c Find the total growth of new number members of new in the members 2nd that and will 3rd be months gained in of 2016. 2016 if this continues. d Explain a The why number the of growth new cannot members continue forms a in this way geometric indenitely. sequence The because b r = 1.5, it a is = increasing by a constant scale common ratio is 1.5. factor. 15 000 Number of new members in 2nd Number of new members in 3rd month month = = 15 000 22 500 × × 1.5 1.5 = = 22 500. 33 750. Use this formula because r > 1. c S = 12 d If = 3 862 390.137… = 3 860 000 growth (3 s.f.) continued in this way, after 36 months Give much (7 greater than current world an example population billion). Examples 6 information and 7 about asked a common dierence. The example next when the you know 15 6 you scenario shows the to — you value of nd the how a E8 Patterns the value rst to series. term form an of a and series, the given common equation and some ratio work or backwards to justify your explanation. A LG E B R A Example Your aunt second 8 gives you 10 birthday and so a Find b On the total which AUD on, amount birthday on given will your increasing you for rst by your have birthday, the rst been same 13 given a 20 AUD amount on every your year. birthdays. 1530 AUD in total? The series increases by a common dierence, so it is arithmetic. AUD b a = 10, d = 10, S = 1530 n Rearrange using ⇒ the and solve, quadratic by formula Interpret n is a number of years, n = -18 does not make your There are Dollar – 17th over Australian birthday, 20 AUD, Practice GDC. the ocially just written Pound in total amount recognized using the given Dollar dollar is 1530 ($) in context The of the problem. – replaced 1966. solving scheme has three Level 1 investors. Each person recruits investors. Each Level 2 investor recruits four Level 3 pyramid scheme four is 2 in Australian Australia A pyramid Level solution AUD. currencies. sign your 6 Problem A your sense. the On 1 or or Since the factorizing, a fraudulent investors, ‘investment’ and so on. scheme. Some members a b Show Write that there down a are 48 formula Level for 3 the number of Level n large prots d Find the Show number that over of investors 1 000 000 000 make most will needed to investors ll eight would be but investors. money. c may investors. lose their Pyramid levels. needed to ll 15 schemes are in countries. illegal levels. many E8.1 Making it all add up 157 2 Competitors at various Thenal in a beanbag distances beanbag from is race the placed run on starting 40 m a straight line: from 20 the track. m, 24 starting Beanbags m, 28 m are and so placed on. In each problem, consider line. your whether answer sense in the t ratS context. Give answers to of 20 24 28 40 meters Competitors run startingline. They tothe 3 starting to the beanbag, this until pick all the it up and beanbags then return have been it to the returned line. a Find the number b Find the total A rst repeat ball is kicked before it falls of beanbags distance into and the hits that air the that each from competitor competitor the ground. each It ground. then It must collect. runs. reaches bounces up a height again, of 6 several m times. 2 Each bounce the is height of the previous bounce. 3 )m( thgieH 6 m T ime a In the Write b 4 Find the sixth time. European bounce, the total the total distance standard ball travels distance it paper has it 12 travelled sizes are m travels A0, (6 in as it A1, The area of A1 paper is half the area of A0 The area of A2 paper is half the area of A1 This 5 rst down (s) relationship dimensions 26 a Find the area b Find the total A set The (3 of block inches), Find the 15 8 by building rst and total continues is 37 of a sheet on, of A10 covered blocks 50.8 length the smallest up returns A2 and 6 second and to the so m down). bounce. ground for the on. paper. paper. ocial size, A10, which has mm. area so to m the contains mm up of by long to all the the E8 Patterns paper. one sheet blocks (2 of inches), last block, blocks of 9 each size dierent the second which combined, is from A0 to A10. lengths. is 254 giving 76.2 mm your mm long long (10 answer inches). in mm. your an appropriate 0 makes given degree accuracy. A LG E B R A 6 In a this 7 tness by 2 a Show b Find c Determine every rst that the Hannah 20 How or day does that the 5 she he km in runs. can and sit-ups rst when 30 20 on does sit-ups the the the 50 on the rst day, and increases day. number Her total sixth sit-ups. total minutes. Find you discuss goal amount of is sit-ups to of is 1100. decrease time she her time would run by for 3% in the tell when a 4 real-life situation generates either an arithmetic series? Series the 30 day does day. runs. geometric D Pedro every he runs time Reect In program, sit-ups ● Can ● What and you arithmetic fractions evaluate are the a risks sequence u series of = that making 8n 2, goes on forever? generalizations? for n ≥ 1, there is no limit to the size n that else n could can take. always No matter name a how larger large value of a n, value and of n hence you choose, nd a someone larger value for u n Todescribe (gets larger this and situation larger, mathematically, without limit), u you also say: tends ‘as to n tends innity to innity (also gets larger n and larger, without Reect discuss ● Explain why ● Explain what 4 ATL and + 6 + 8 + this 10 In all terms these of + 12 if + could you 14 + try go to on nd forever: the 4, value 6, of 8, 10, this 12, 14, … series: … 6 sequences the 5 sequence happens Exploration 1 limit).’ sequence n ≥ as 1. n For tends each, to determine innity what (becomes happens innitely to the Tip large). You your could GDC use or a spreadsheet. 2 For each ratio, r. geometric Describe sequence how the in value step of r 1, nd aects the the value of behavior the of common the sequence. Continued on next page E8.1 Making it all add up 15 9 3 a Show that the areas of the squares 1 and rectangles in this diagram 32 form a geometric sequence with 1 8 rst term 1. 1 16 b Explain why the area of the whole 1 diagram represents geometric the sum of 2 a series. 1 c Use the sum of 4 Explain diagram the series how diagram to you below to 1 determine + could + + use the the + 4 …. illustrate that 1 2 2 Exploration geometric number 6 shows series. of It terms that is an even you can nd interesting in a nite the sum notion amount of that of an you innite can add decreasing up an innite time! In a decreasing geometric series, each is term smaller Example than previous Find S = the 10 + value 8 Common S = 0.8S = 0.2S = S = + of 6.4 ratio 10 + the + geometric 5.12 = = + … 0.8 8 + 6.4 + 5.12 + … 8 + 6.4 + 5.12 + ... may fraction. by the 10 = have 50 used Example 16 0 a 10 one. series: Multiply You the 9 similar shows method how E8 Patterns to to do convert this. a recurring decimal into a common ratio and subtract. A LG E B R A Example Express 10 0.27 Let as a fraction. x = 0.27 100x = 27.27 Multiply Then by 100 willcancelout 100x = 27.27272727… x = 0.27272727… 99x = x = - 2 Find the 3 = 1000 b S = 10 + 9 c S = 20 + 12 innite An the By a + the + 8.1 + of + 7.2 the of the x it is = + part subtract. 125 + 4.32 + series. … … + series … has rst term has second 36 and second term 12. series. series term 25 and third term 5. series. each as a b geometric series, 0.37 express c as a fraction: 0.207 d 0.148 + 0.4 solving 0.55 the as a fraction formula sometimes n + 7.29 geometric sum geometric 250 0.2222… Examining S 500 considering Express why each geometric Problem 5 of + sum innite Find 4 value S Find repeating you 7 a An the 27 Practice 1 so when for the possible to by writing sum of nd it the the as x = terms sum of 0.55 of an a + 0.0055 geometric innite + 0.000055 series geometric + … shows series. 1 r = a when r > 1 or r < -1. n 1 r n If r > 1 or r < -1 then as n gets numerator of the very n large, r gets very large. Therefore, the 1 r fraction gets very large, hence S gets very large. n 1 S n r 1 r when = a 1 < r < 1. n 1 r n If 1 < r < 1 then as n gets very 1 numerator of the n r large, r gets closer and closer to 0, so the fraction gets closer and closer to 1. Hence, S gets n 1 r 1 closer to 1 r E8.1 Making it all add up 1 61 You can nd common The sum ratio to Example A r ÷ u u 4 r value of when innity 1 an < r innite < geometric series with rst term a and 1. is for |r| < 1. 11 geometric = the series has third term 6, fourth term 4. Find its sum to innity. = 3 First |r| < 1, so the series has a nite show that | r | < 1. sum. 2 u = ar a = 3 2 so u ÷ r = Find 13.5 3 Practice 1 8 Determine + 7 whether a 10 + c 2 + 4 + 8 + e 1 + 0.1 g 3 + 6 + 4.9 + or not each series has a nite sum. 3.43 + … b 10 16 + … + 16 384 d 2 + 0.01 + 0.001 f 1 9 + + … h 3 12 + 0.0001 + … + + + 7 4 + 4 + 1 + 6 + 0.2 + 0.04 6 12 + 8 + + + … … + 16 384 0.008 + … … 1 2 A geometric series has rst term 4 and common ratio 3 I a Write down the rst three am incapable of conceiving innity, terms. and yet I do not accept nity. Simone de Beauvoir 3 b Find the c Find its An 4 An sum innite Show that sum to has a Show that there b Show that one 16 2 the ve series nite geometric nd rst terms. innity. a then the geometric it innite of series are two value other has sum, of rst and has possible E8 Patterns values of second of 24 for ratio the and sum term common value 18 the second possible the term nd the and the to fourth common gives sum term 15. series. the term ratio. series innity. 1.5. a sum of 128, a. A LG E B R A Problem 5 A geometric Find 6 A A its sum to sum to has rst term 6 term x and a sum to innity of 60. ratio. series innity geometric Its series common geometric Its 7 solving is series innity has rst 75. has is Find the and second value rst term x 2.25. Find the and of x term x 3. x second value term of + 4. x Activity The Koch starting with Snowake with four an is a geometric equilateral smaller lines, triangle like pattern (Stage called 1) and a fractal. then It is replacing formed each by line this: Stage Objective B: ii. describe Make a Stage the shape. number Investigate or Explore as mathematical the some Investigating patterns all to patter ns general rules observation the consistent about perimeter, or the some with patterns; ndings for conclusion example, about the a rule eventual linking area of Stage the of how geometric these the the number ● the length ● the total of of properties of the Koch Snowake by answering number line each relates segments of the line in to: the diagram segments perimeter Stage ● the number ● the area ● the total could Sierpinski 2 questions: Stage ● You 1 of of triangles each in triangle the in 3 diagram the diagram area investigate Triangle, other which fractals, you can such search as for the Gosper Island or online. Stage E8.1 Making it all add up 4 16 3 Summary An arithmetic arithmetic A series is the sum of the terms of an sequence. geometric series For a geometric common is the sum of the terms of ratio series means S r the sum of the rst n terms of a of the rst n consecutive an > 1 or r < -1 |r| < 1 can nd the sum of an innite geometric = series For and positive You integers a series. when sum term sequence. n The rst a when geometric with r : arithmetic series with rst term u = a and n terms, with when 1 < rst r < term a and common ratio r 1. 1 common dierence d, the sum of the rst The where u is the nth term, sum to innity is for |r| < 1 or n Mixed 1 Find practice the sum of each 9 series: An arithmetic The a 1 + b 34 3 + + 5 31 + + … 28 + + 1 + 4 + d 50 000 16 + 25 … + … + + 10 000 An arithmetic Find the Find a + 2000 + … + has 32 series terms. has ten eighth terms term is 48. 405. common dierence. fraction equivalent to: begins 15 + 0.2 Find its b 0.18 c 0.123 0.64 19 + 23 + An arithmetic series has second term 9 and … fth and rst 1024 11 2 series the -2 a + of 197 10 c sum term 30. Find the sum of the rst 104 value. terms. 3 Find the value of the arithmetic series that 12 begins 18 + 17.2 + 16.4 + … + An arithmetic sum 4 A 15 geometric terms. series Find the begins sum of 10 + the 8 + … and has A geometric eight 6 An terms. series Find arithmetic begins the series 8 total has + and has of dierence 11. rst Find 12 + the … 5 of Find of series ratio has 1.25. rst Find term the 8 sum of the 10 has fourth terms term and is term 40, and the 520. common dierence. A geometric sum of series the has rst six common ratio terms is 1995. 1.5, and Find An of its innite a sum the term. geometric series has third term 128. Find the sum of E8 Patterns innity common An arithmetic 96 series of 15. has rst Find term the 10, value of the ratio. series dierence has d. rst The term rst a ve and terms have and 240 and the rst ten terms rst Find terms. to the sum term rst rst 16 geometric 16 4 series rst rst common seven the the and terms. fourth and Find solving geometric common A 11, 585. the and 8 term is and sum 15 eight rst terms terms. Problem A has fteen dierence. the the value 7 rst arithmetic sum series. term the An the rst14 the common 14 common of series. 13 5 series 2. the values of a and d have sum 630. A LG E B R A 17 An arithmetic common seven series dierence terms is 182. has x. rst The Find term sum 2x of + the 1 and 20 rst In I x A geometric series has rst term x and I received 15 19emails. as 18 January received I emails. predict anarithmetic 11 In emails. March that this sequence. In I will Find February received continue the total second numberof emails that I would receive in the 100 term x 3. The sum to innity is whole year. 3 Find the value of x 2 21 19 I receive $10 birthday, 12th to me birthdays Review A 14 rst in and by in small uncle 11th so my on. on Find uncle my 10th birthday, the from $12 total my on my to week, 12 third 10 two business grows mobile phones phones week by and phones by in so the of be The repaired second on, every word phones. will down phones an why each week Find the half the area of A4 paper, half the area of A5 paper this have b as in the the continues sheet each Find the of on A4, total an number of owners continue week, to sell the in assume follow Determine the total in assumption nth for the number of week. of phones network and a of large their is that a the the rst movie will see repaired sequence. A repaired in network possible of rst number of phones repaired in computers the of directly engineer network just be had one a second Adding a new Past expects lm in its experience week, the that rst tells number 1 000 000 week her of in that in lm will be 80% of the people week , T 3 people the third a each includes with her modelling the number the rst Explain assumptions second month a rst your Show of network will this on only to the a server can other. test all the network. one terminal, connection to test: there Server-T terminal adds and T -T to they that will is the why will prints they sell sell 120, and 100 and adding more: -T 2 add 2 three 3 the nth another n terminal to Hence explain why added the number when the nth of to forms c estimate. sells T-shirts. shirts. in the In arithmetic terminal numbers form is sequence. in an Find the total connections an an the third 50 d the of possible network when there a are terminals. Determine would to number in lead the to number 2080 of terminals possible that connections test. 144. these the connections. who lm answer only T 3 -T 1 adds more estimate see your and two before. accuracy. answer month sell who Give company month they people weeks. degree why internet their of eight appropriate In if which each wants terminal 1 Explain added An months terminals Server-T connections 3 they correct. connections connections: b Use shirts 12 will sequence. the weeks. producer subsequent the …, 1 total 10 her cinemas. see sales geometric number number communicate phones arithmetic A Server-T A paper. A6, area. 2 2 A10 week. Find the to A5, mouth. number forms The Adding c pattern one paper. would 10th cm has If b 625 has increasing week expression repaired Explain of paper in 4 Write area paper A10 repairs predict capacity a an A6 I 20th has A5 and amount 10th paper context business the my my (inclusive). managers the on birthday given 1 from $11 A4 geometric sequence. E8.1 Making it all add up 16 5 5 A blog gains month, in its 150 000 120 000 third in followers its second in its rst month, 7 and 96 000 A in month. parcel two They Show that the number of new month in the rst three to cities: c in its the website A new gains in its and a Find the months forms for the the of fall blog to music in the of have subsequently nd open that it gain in down rst in rst to 13th subscribers basis, with ofthe its rst c and start running in follow starts each Assuming of of its this of have can its third 2500 month, increasing subscribers of new 13th by it Write subscribers month number on a attracting of if a it 16 6 fourth connect new only as They and monthly subscriptions overall that down the would it do not to service generalize can of and processes E8 Patterns all in of if additional they were Doncaster, previous if each the c number if inquiry? Give specic justify and patterns solutions. as Find connections the expect additional Falmouth, Doncaster. 75% leave maximum statement products, to open to routes and open then depots. each needed other Determine is as the total for to Edinburgh one number their be in in of entire network connected directly warehouse. how before the would exceed examples. depots well the warehouse discuss forms improve number required warehouse continues. the the be model. members the explored dierent help services: the Statement of Inquiry: Using new service month, year, decrease new that and you two Birmingham– total. to nd trend Reect How the month subscribers this to and way, before. service, in year. number gain month, number month warehouse, followers same b the third month. number the would continues After a Cambridge. that Write daily a a b a packages. would followers in streaming its 4000 each new in number whole amount total to expect month, continues, that number subscribers the would Birmingham. with months. maximum second on pattern continues subscription constant a six should 1000 so this followers that month nd of rst Assuming per 6 that number gain warehouses sequence. Assuming the with and warehouses Aberdeen–Cambridge b starts Aberdeen the transport Cambridge, geometric service followers They per UK connect service a delivery many number 200. of depots could connections be built needed Another dimension E9.1 Global context: Objectives ● Understanding three ● the formulae and using coordinates ● in F Using distance, in three Pythagoras section and dimensions and can How can 3D Finding the angle describe space in three you nd distances and angles solids? How does your understanding of 2D C dimensions space ● you in ● three expression questions How in trigonometry cultural dimensions? ● midpoint and between a line and a extend to 3D space? plane ● How a can given ● Can ● Is a you divide a line segment in ratio? 4th dimension exist? D ATL human activity random or calculated? Critical-thinking Analyse parts complex and concepts synthesize them and to projects create new into their constituent understanding 7 3 9 1 E9 1 Statement of Inquiry: Generalizing the relationships construction and between analysis of measurements activities for ritual enables andplay. 167 SPIHSNOITA LER ● Inquiry dimensions Using Personal Y ou ● should nd the points already distance in two know between how two 1 Find dimensions two a nd in the two midpoint of two points 2 a use Pythagoras’ theorem right-angled in 3 and 6) 7) (2, Find triangles distance ( between the 9) 2, 30) midpoint and 6) (7, and the answer (7, and the (3, b ● 5) (5, Find dimensions the points: (4, b ● to: ( the points: 9) 2, length in of 9) of exact side (surd) x, giving your form. 11 x 8 ● use in trigonometr y right-angled to nd angles 4 Find angle y, to the nearest degree. triangles 6 cm y 4.5 Describing F You can world at How can you describe ● How can you nd describe three surfaces computer say when To – space for screen. two example, But a and describe cerealbox, 16 8 in dimensions. creating Reect ● space ● has a they of discuss cuboid, or and computer not a three useful new dimensions? angles using dimensions for 3D very giving or in solids? coordinates, are program building to useful display but for a 3D real something instructions using the describing in 3D an object shaped would like you a cuboid, give? such as on a space, printer. 1 measurements E9 Space in dimensions a are space distances Two in model what cm a G E O M E T R Y To fully three You describe objects perpendicular can describe such as cuboids measurements: positions in 3D in width, space three depth using x, dimensions, and y you A N D T R I G O N O M E T R Y use height. and z coordinates. Tip The x-axis, y-axis and z-axis are perpendicular to each other. The convention is y to z draw y-axes the as if horizontal of a the x x- on the base cuboid, z-axis and and pointing upward. O A at surface y-axes is named The the in x 3D y space plane, is and called the a plane. planes The plane including the containing other pairs the of x- axes and are similarly. cuboid below is drawn on a 3D coordinate grid. y z D C F G x O E From the origin O y-direction, and To point nd the 1 to point unit in with A the is 0 units in z-direction. coordinates (3, the x-direction, The 4, 1) coordinates start at the 0 units of A origin in are and the (0, 0, 1). Tip move: Some GDCs dynamic 3 units in the positive x-direction to point E 4 units in the positive y-direction to point F 1 unit software 3D and graphing can graphs. draw Practise plotting some points. in the Example Two points Calculate C has so it z-direction, to point C 1 have the the is positive coordinates distance same x vertically and C (3, 4, 7) and D (3, 4, 18). CD y coordinates above as D, D The 7 ( 18) = distance dierence CD = 25 move With a between C and their z D is the coordinates. units Objective iii. between 25 C: Communicating between some diagram. specically dierent questions in Sometimes mention forms Practice it might 1 of you help to mathematical will need draw a to representation translate diagram, written even if the coordinates question into does not it. E9.1 Another dimension 16 9 Practice 1 Write 1 the (x, y, z) coordinates for each lettered vertex in these cuboids. z y a b z D (4, 9, 1) E G B (0, 7, –2) H A x F x O C (–5, 2 Find the distance between a (1, 1, 4) and (1, 1, 11) b (3, 2, 0) and (9, 2, 0) c ( 2, 11) and ( 4, The 4, space straight diagonal line joining of these 11, a one pairs of 0, O –2) points. 11) cuboid vertex is the H G to E the opposite the center vertex, passing through F D of the C cuboid. A A face diagonal one vertex one of the to is 1 box faces of the the theorem 2 passing joining B through shape. cm triangle to line AG is the space BG the face is diagonal diagonal 1 measures Sketch straight another, Exploration This a nd by BCA. the 3 cm Use length by 6 cm. G Pythagoras’ of CA. Give F your answer in exact (surd) form. C H 2 Sketch the triangle GCA. 2 cm B E Label the lengths of GC and CA D 6 What is the size of ∠ cm ACG ? 3 Explain 3 Use 4 Find 5 Another the box’s A you Pythagoras’ Using 6 how length box the Find, same space cuboid in is theorem BH. 1 to What cm deep, method as nd do 4 the you cm you length notice wide did to of GA about and nd 8 GA cm GA, to 1 decimal and place. BH ? long. nd the length of this diagonal. measures terms of x x cm and by y, y the cm by length z cm. of one of its face diagonals. Continued 17 0 cm A know. E9 Space on next page G E O M E T R Y Hence show that the space diagonal has A N D T R I G O N O M E T R Y length z y x In a cuboid with dimensions x, y and z, the space diagonal has length The is space also volume Reect How many dierent ● How many space ● In the is rst the Practice 2 Find the length a cereal b a room c a pencil Find a the box box that of cardboard b a smartphone c a storage length pencil 16 cm Sets of known 4 If a 3 9 cm cuboid cuboid between of diagonal cm by space 1, G have? explain and have? Are why ts by the 4 7 of 12 m 2 cm 50 by cm dimensions 13 space an 7 by m, 26 of 20 space diagonal cm which is 4 14 m tall cm. each by are inches diagonal exact diagonally 2 integers 4 cm. cuboid, giving your answer 15 cm 123.8 by of 13 a by 22 mm by inches cube cm 58.6 by 18 whose mm by 7.6 mm inches. sides are 5 cm. form. has 5 into Find which three 5 length form 2 + integer are cuboid called 12 shaped of the sides box pencil of include a with 2, 2, 3} and 2 + 23 {2, correct to right-angled {3, 4, 5} and 3 s.f. triangle {5, 12, are 13}, 13 and also Pythagorean 14, dimensions 2 = sides a the Examples 2 and a the can triples. 2 = 2 + equal? cuboids: an integer space quadruple. 2 2 the all A these cm by diagonal measuring in by numbers include{1, and they accuracy: measuring 2 + cuboid thefour of 2 Pythagorean 2 because a solving cm three as a does Exploration space whose answer just by the box box Problem A in does measuring is degree a your the oor length the diagonals distance measuring a Find face shown of with suitable Give 4 box diagonal 2 diagonals shortest the 2 a to 3 discuss ● GA 1 and diagonal called 23, 27}, because 1 2 + 2 diagonal, Examples 2 + 2 of these 2 = 3 2 = 27 E9.1 Another dimension 171 Exploration 1 Points D (19, of a h, C (4, 17, a 7, 17) cuboid and 11) are of depth Write 2 and two width d as down D(19, 17, 17) vertices w, height h shown. the values d of w w,h b 2 and Hence Points P nd (x 1 P (x 2 , y 2 , depth a w , z ) the y 1 2 cuboid C(4, d , 1 ) CD and (x are = – x x two vertices of w, height . Write for show P h h, The distance The distance Reect two d that and the P (x d , y 1 , z 1 w ) 1 distance is . 2 formula between two points P (x and discuss dimensions, the , y 1 , 1 z ) and does Example d this to (x 2 , y 2 , 2 z ) is: 2 3 distance between (x , y the distance formula ) and (x 1 in , 2 three y ) is given by 2 dimensions? 2 distance your relate P 1 1 the ) 2 h 1 Give z a and similar and 1 Find , 2 1 between How y d Hence In , 2 1 width 2 ● 11) 2 of expressions b z distance 7, answer between correct points to 3 (5, 7, 3) signicant and ( 4, 8, 2). gures. = Substitute the values into the formula. = Be = 9.11 (3 17 2 s.f.) E9 Space careful with the negative numbers. G E O M E T R Y Practice 1 Find 2 the a (0, c (23, 11, e ( 11, a Find b Use 3, 0) and 18) Three Show 4 Show In this plane. CE points the of points, 11) 3, OA, 19) where to nd coordinates plane an O is the the giving b (5, d ( 6, f (5.5, 4, origin distance is an in between ABCD is O (0, isosceles coordinates forms ABCD Theangle and (33, forms have PQR cuboid, 17, method have OAB that pair 6) (17, and each your 8) and 3, 2) 11, and from answer (6, and 4) A is the 8, the 7, form. ( 9) 4.5, point origin exact 10) (0, and in to 1, (4, B (3, 13.5) 6, 12). 14, 18). solving points Three and similar that 3, distance Problem 3 between (2, 16) the a T R I G O N O M E T R Y 3 distance 0, A N D P (0, isosceles a 0, 0), A (3, 6, 6) and B (4, 9, 1), Q (1, triangle. 5, Find 9) and the R (5, area 7). of 1, 2). triangle G diagonal labelled PQR F horizontal the 4, triangle. E θ H B θ C A Example 3 D Find the Give angle your between answer to the the diagonal nearest CE and the plane ABCD in this cuboid. degree. F G E H 2 cm B θ C 3 A 4 cm cm D 2 AC ⇒ 2 = 3 AC = 2 + 5 4 = 25 Find the length AC. cm E 2 Sketch cm the triangle ACE. θ C A 5 tan θ = θ = tan θ ≈ 22° cm Use the tan ratio. 1 = 21.801…° E9.1 Another dimension 17 3 Practice 1 Find Give the 4 angle your between answer to the the diagonal nearest FD and the plane ABCD in this cuboid. degree. F G E 4 cm H B C θ 5 cm A 12 2 a In cuboid length of PQRSTUVW, PR is 149 cm show D that the W V cm. T 3 cm U b Find the angle between VP and the plane S R PQRS correct to the nearest degree. 7 cm P 10 3 a In cuboid the ABCDEFGH, diagonal BH and nd the the plane angle ABCD Q cm between to 1 H G d.p. E F b Hence nd the angle between BH and the plane EFHG 8 cm D C 4 cm A 4 4 In this triangular right-angled prism, triangles. BCE The and other AFD faces B cm A are B are 2 rectangles. E F a Find the length BC, correct b Find the length DB, c Find the angle to correct to 3 s.f. 3 s.f. 10 CDEF, d Find correct angle that to BCE, DB the the makes nearest angle with the plane degree. between D planes the 5 nearest ABCDE The is point which ABCD is a is the Find b Hence c Find EB d Find the CDEF, correct 5 C cm to degree. square-based E a and 8cm right directly midpoint of the pyramid, above the with point AB = 8 E cm. M, base. BD nd BM D C M angle Giveyour between answer to EB the and the nearest base ABCD degree. A 8 1 74 E9 Space cm B cm cm G E O M E T R Y Problem A N D T R I G O N O M E T R Y solving 3 6 The volume Tothe nearest longest 7 Micol east As face holds and 4 soon cuboid decimal the string due the lets length to the The 440 place, cm . what The is base the measures length of the 5 cm ● How does ● How can midpoint a of go of kite 1 m Rachel, of the the kite above who kite it string, is ground Conjecture a level. holding rises 11 m assuming the He kite (x 2 2 Use B , 2 your (19, 19, cm. vertically that it stands at y , your you 6 m the due ground. makes a straight line understanding divide a line of 2D segment space in a extend given to 3D space? ratio? 3 of the similar z 2 on upward. line segment joining (x , y formula for the midpoint ) and (x 1 , y 2 between ) is given by 2 P (x 1 P 8 space 1 and by cuboid’s kite. Dividing Exploration 1 is of north Rachel Micol C ATL a diagonal? m as Calculate from of , 1 y , 1 z ) 1 ). 2 formula to nd M, the midpoint between A (7, 11, 14) and 38). Continued on next page E9.1 Another dimension 175 3 Use 4 Explain the the distance why knowing midpoint 5 Find the 6 Hence 7 Prove formula of that AM = that BM AM is = not BM enough to show that M is AB how your that verify AB distance explain to you can formula be from certain step 1 that gives M is the the midpoint midpoint of of AB segment P P 1 Example Find M M, 4 the midpoint of A (3, 2, 9) and B (1, = = 8, The 3, midpoint given by Example P, Q Q is and the the mean of the x, y and z coordinate values in A and B 3) M of the line segment joining P (x 1 is 3). Find (2, 2 R , 1 y , 1 z ) and P 1 (x 2 , 2 y , 2 z ) 2 M 5 have coordinates midpoint of PR. ( Find p, p, 3, q 8), and (1.5, q, 9), and (7, 2, r) respectively. r Use the midpoint formula. Therefore: Form equations using the x, y and z ⇒ coordinate Practice 1 Find the 5 midpoint a A(0, 0, b C (1, c E ( d G (1, e I ( f K (1.7, 1, 2, and 1) − 6, 0, 11, 17 6 0) 8) 32, and 1) and 12) − 0.4, of each B (4, 8, D (25, and 11.8) of points: 16) 11, F (− 4, H (8, and pair 10, E9 Space 4, 23) 8) J (− 4, and 7) 7, 5) L (2.3, 4.1, 12.1) values. Solve for p, q and r G E O M E T R Y 2 Two M 3 points is the Three and have points R (4a + Points and same. 5 A, Q is P, the Find a both The c b < h line 2 : ATL and g < midpoint parts, Two 3) and M (11, coordinates P (a the 2, b, midpoint coordinates that the 2c), of have of of Q (a PR. + in : b a, + b 3, 3b) and c PR. The P (a, letters is used of 3, of 11), AC B ( and on the nds ratio dierent in P 3 2, 11, 1), midpoint C (7, of BD 11, are 7) the a to b, i integers 1 Q (d, e, represent exactly statements c), f ) the and R( g, integers h, i ). from 1 to 9 once. to 9 are to the variables a to i such that satised: how the 1 : point 1. that How proportions, would you divides would for nd a you line nd example the point a the that segment point ratio 1 divided into that : 2 a two divided or the line a ratio segment n ? points lies 0.5). 2, Find 4 Tip the x-y plane have coordinates P (x 1 P 3, B ABCD coordinates integer A (1, midpoint quadrilateral formula m have assignment Exploration 1 1, the e into ratio is mathematical Generalizing, the D each thus segment 3? into R midpoint < Q Show the and these < 3c). and 19). possible of a equal C 3, Q inclusive, A (1, Find coordinates 3b, Describe Points AB. T R I G O N O M E T R Y solving B, D (10, of have 3, Problem 4 coordinates midpoint A N D P 1 and divides it in the ratio m : , y 1 ) and P 1 (x 2 , y 2 ). When 2 n that 2 you P write divides P 3 in the P 1 ratio m : 2 n, y P (x 2 , y 2 ) the 2 so n order matters the m section closer to P and the 1 n section is closer P 3 C to P 2 m A P (x 1 a Explain why triangles AP P 1 b Find the scale factor that , y 1 B ) 1 , 3 BP P 1 , and Hence show that P A P 3 transforms P BP 1 c CP 2 = and to are all similar. 2 AP 2 P 1 derive a 3 similar expression 1 for AP 3 d Use your expressions for P A and AP 1 P are given by to show that the coordinatesof 3 . This is called the section formula 3 Continued on next page E9.1 Another dimension 17 7 – is 2 Points 3 A and a Use b Verify Verify the 4 Two have section that that matches C AB when the points coordinates formula = nd m = n pointP , = 1, the coordinates Suggest which lies a Use UV P and 2UT formula the (16, = ratio 30, section If (x 1 P , y 1 has 3 3) to : C (10, divides 16). AC in the ratio 2 : 1. 2 formula in two dimensions (x , y 1 , z 1 formula and ) and P 1 for divides (x 2 it the in , y 2 , z 2 ) coordinates the ratio in three 2 m : of the n 2 nd the where coordinates U and V respectively. Use the of have T, the point coordinates distance that (1, formula 5, to divides 8) verify that 3VT The P P 1 your in which section P suitable on 3 5 and formula. 1 dimensions. B, 2) 2 BC midpoint have to A (4, , formula z 1 ) and P 1 (x 2 , y 2 , z 2 ) where P 2 divides P 3 P 1 coordinates in the ratio m : n, then 2 . 3 Example Point and T U 6 divides are (4, the 3, line 8) segment and (24, SU 18, in 21) the ratio 1 : 4. respectively. The Find coordinates the of S coordinates of T T = = Substitute (8, 6, Practice 1 2 3 Use the 2.2) 6 section formula a Divide A (5, b Divide C (− 4, c Divide E (11, Use the section a Divide A (1, b Divide C (3, c Divide E ( Find point the (4, 17 8 11) 6) 4) and 2, 2, and and 7) D (5, F (1, to to 27) 0) 24) B (25, 6) and D (15, 3) the and of a E9 Space (24, line the the the 9, 6, 4) 0) 1, three − 4, 1 ratio line in in 2 in fths 1 : : the given ratio. in the given ratio. 2. : 3. ratio ratio the of in 3. segment the the 24) 42). segment ratio ratio each F (12, point point in in divide and 8, each in 5) coordinates 6, divide B (25, formula 3, to 1 3 : ratio the : 2. 1. 4 way : 3. from the the values into the formula. G E O M E T R Y Problem 4 Three P (2, 2b). simplest T R I G O N O M E T R Y solving points 21, A N D have P form coordinates divides and AB hence in A (a, the nd 11, ratio the b m values + : 1), n. of B (11 Find a , the and 36, 3b ratio + m 1) : and n in its b D ● Can ● Is a 4th dimension human activity exist? random or calculated? 2 In two dimensions, the distance formula ( is 2 three dimensions it ( is x - x 2 1 x - x 2 1 ) 2 2 ) ( + y - y 2 1 in two dimensions the midpoint + ( z - z 2 1 x dimensions it + formula What ATL if in two you and of 1 the you form Use your , x 1 2 Use 3 , y 1 your a (0, 0, b (2, - 4, c (1, 3, Use , 0, , (w 1 your 4 x , y 1 Use your Use your 6 Explain What could In book his life in one we a it have (w z and ) x 4, (7, 3, of , to in x + x 1 y 2 + y 1 2 is , 2 and in 2 There is a clear link between the to contain four 4, another letter, w ? dimensions, with coordinates , z in two distance and three between ). distance between each pair of points: 0) 12, a y 2 15) midpoint formula , z 2 nd the 2 5, , formula for 4) the x distance formula the formula for the in two midpoint and three between ). 2 M, formula your answers and to A whose the to midpoint between A (7, 4, 1, 3) to consider Romance they misunderstood we nd step the 5 distances support AM, the BM claim and that AB M is the B geometry of inhabitants that which and 1). distance mean in 2 1, (w y 0, 2 A , conjecture and 2, a 2 (7, formula of the nd (1, 1 discover dimensions , to and Flatland: world day , how midpoint and to 3, 5 of knowledge 1 andB ( and 8) 2) dimensions points conjecture formula 3, , 2 2 formulas 2 0) z ) z). 1 0, + 1 1 dimensions. draw y, to ) z 2 y 5 x, z 1 y 2 these knowledge dimensions (w 2 three could (w, + 1 . extended Exploration Imagine y 2 is formulae x 1 2 ) three y 2 ) Similarly, ( + are the actually space cannot Many believe we in more than Dimensions, they part live in? Edwin occupy of a 3D Could three a 2D Abbott space, universe. there dimensions? be explores but then Similarly, other could geometric perceive? E9.1 Another dimension 17 9 Some that as problems we inhabit many this as 12 makes Is ● Explain ● Show that test square, to equal Show Do to maybe nd is meant you can you the time been three the goes understood dimensions time on better being, – we scientists imagining sometimes can’t will by know develop using whether a greater it we 4 by the points apply must familiar term T (1, 6, geometric isosceles 5, 8), shapes in 4D? triangle U (5, 2, 4, 4) and V (1, 1, 0, 0) square is that A (0, four dimensions? Is it sucient and 0, the in BD 0, 0), points length, must B (6, A, also 4, B, C diagonals 2, be 13), and AC equal C (2, D to and in form BD a must length. 10, 15, 11) and square. possible can’t for equal AC a in sides? be and form is a equal points 2) think dimensions than For describe identify four sides 13, have triangle. midpoints, 6, as and three you that D (− 4, more problem. discuss the four physics idea. have that all with a isosceles could simply ● but the what an How ● of possible form have space and ● One theoretical solve sense, Reect ● a to understanding it in that we could be living in a world with see? Summary ● In a cuboid with dimensions x, y and z, ● the The P 1 space ● A at The diagonal surface plane has in 3D space containing plane, pairs of and axes the are , y 1 , z 1 ) the is x- called and a 1 planes y-axes named including the is distance The distance (x 2 , y 2 Mixed 1 Find , z 2 A 13 inch to 50 a between of cm the by P (x , y 1 space 15 reasonable The section If (x P 1 , z 1 is joining given by 2 formula , y 1 , z 1 P ) and P 1 P (x 2 in the , y 2 ratio , 2 m : z ) where 2 n, P 3 then 2 P has 3 ) coordinates and 1 cm diagonal by degree 22 of of cm. a shoebox Give your by storage 18 drumstick box inches. would E9 Space measures Determine t into 3 Find the these midpoint pairs of of, and distance points: accuracy. solving shaped inches 18 0 2 ) formula length cuboid 20 segment z practice the by 2 , ) is Problem 2 line y 2 measuring answer 2 , the similarly. 1 P the (x other 1 The of P M plane. divides ● M and length ● x-y midpoint (x the 13 inches whether box. a a (1, 1, b (5, 5, c (13, 3) and 2) 2, (3, and 11) 2, (6, and 1, (9, 9) 10) 2, 4) between, G E O M E T R Y 4 A straight path coordinates axes are runs B (0, 3, measured directly 2) in and from C (15, points 6, 8), with where b The the middle of216 meters. angle any a Find the length of the path and m the of its Find the ends of dierence the in height between the A single totwo Determine strand from of a spider web runs in a one opposite shaped Two points if like and 3 corner corner a of a room at the oor Find at cuboid meters the the 4 ceiling. meters The wide room by 6 19, ratio Find the 6 angle tombs famous of the strand of a Each of height the with tag in One To one of C (150, be Give at base m. the played the Two web and B The of the 42). 2 : 9 In the its top your answer. coordinates A (13, 2, 7) and Find the point that divides AB in solving points Find the most Great and have 7). divides A B ( 10 the or B is 1, coordinates its any divides in the closer have z). A Show that C (5, A UV points 3, and angle and answer 1, Two the − 4, ratio to U ( the all B 5, : the 3. 11, 17) 1 : and 2. which origin. 11 A ( form ratio Determine A (3, possible are points 3) 1 in coordinates Find and UV an values units 13, 5, 2, 8) for and z apart. 4), isosceles B (11, 6, triangle. 12) Find area. of accurate it, to ‘tag’ the designers to simulate representing one corner corner each arenas of from the outdoors, other is in used the one the or with 3D rectangular origin is With was the prism, at creating 3D space video to characters. creating two coordinates while In one to 17, runs programmers game to game, tunnels. GH 17) the geometry E (22, tunnel G (28,19, games, create transformational and space, foot. When use Arizona, a 2 a Tunnel 16) and from H (213, objects programmer EF has F (215, end 30, and move end 28, 18), coordinate 19). 20). a a Justify 5. giventhat m, pyramid your built Giza. 230.4 indoors largest system 120, similar. places. trying plan furthest the of were pharaohs. 145.5 sides. of unit are context can originOas the strand Egypt measures base decimal coordinate with the players lasers. USA. the pyramids of Giza sloping two Laser sides of in and three measures Review 1 queens the between to between pyramids the Pyramid pyramids web. of for are two meters oor. Square-based as places. tall. length the and answer is V (7, b your to 8 a sides the pyramid Give decimal these have Problem long the base Find straight the the of sides. m. path. B (34, line has 143 two 7 5 Giza of base sloping mathematically the at height midpoint. c b a T R I G O N O M E T R Y the accurate coordinates pyramid and between of A N D arena, a refuge tower is located along the so that Find two the dierence between the lengths of the tunnels. 3 is of the way line joining b There is a sign at the midpoint of the tunnel 4 O and the b C Find coordinates of the top entrances of tower. The company lasers away. will Find Determine the travel that reliably appropriate c the for of the the the targets whether use longest within middle makes hit within distance the this your structure arena lasers up if to says 175 lasers that feet c the sign. An access of one and H corridor tunnel tunnel. are F Find to the Find runs the the coordinates from the midpoint length of this of midpoint the other corridor. arena. laser you could stood in the oor. E9.1 Another dimension of 181 3 A new roller straight The coaster tunnel roller that coaster ride is passes gains designed through speed as to a it have natural passes a long a hill. tunnel before turning sharply as it starting emerges. control center is situated at (0,0, 0), shortest and distance nishing between her points. Suggest and reasons why the distance she travels The will ride the through b the Find on be greater than this. a 1 scale of A (15, a 1 25, Find of b unit 26) the this Find If total tunnel the the 1 and m, the leaves to the tunnel the change total Problem c to hill in enters at the B (75, height hill 50, from c at 14). one Given that her the minimum the slope. average time speed needed is for 20 her ms to , ski nd down end other. length of this tunnel in meters. solving tunnel is created by boring a cylindrical 2 hole with estimate Explain d A cross-sectional the why refuge two a volume your point thirds of coordinates is the of earth answer to be way this of area is built from refuge to an in A of 9 be m , excavated. estimate. the to tunnel, B Find the point. Another 4 A skier travels down a straight ski slope. slope, units measured in meters, her starting to the ski lift are (4, 7, 2). The the point where she nishes are ( 208, 355, d to the his the ski Find The ( you have nish. slope, he skier 370, to ski the statement of and analysis 18 2 relationships of activities between for E9 Space ritual inquiry? measurements and play. loses leaves 75) nd his and ski down from the the starting of the way control and drops one Give Find the distance f Find the angle from the café. specic enables the of the point where he of examples. construction his skis then at walks a café back at up point to the pole. e Statement of Inquiry: Generalizing route line pole. discuss explored same Three-quarters coordinates the male 240, slope How the straight poles. the drops and a 78). of Reect in coordinates down of travels heading coordinates point relative skier With from the elevation café of to his his ski ski pole pole. Mapping the world E9.2 Global Objectives ● Finding the context: Orientation Inquiry area of a non-right-angled ● triangle F ● Using the sine ● Using the cosine How Using area sine can you nd the area of a non-right- triangle? How does the area formula help you nd rule of a segment of a and cosine rules to area of other shapes? circle ● the time solve problems How is the sine rule related to the area of C involving a bearings ● triangle? How is the cosine Pythagorean ● D Apply is How do related to the theorem? more thecosine ● ATL Which rule useful, the sine rule or rule? we dene ‘where’ and ‘when’ ? Transfer skills and knowledge in unfamiliar situations E7 1 E9 2 E11 1 Statement of Inquiry: Generalizing in space can and help applying dene relationships ‘where’ and between measurements ‘when’. 18 3 S P I H S N O I TA L E R ● the and rule the Finding space questions angled ● ● in Y ou ● should nd the given already area two of a know triangle 1 how Find perpendicular the to: area trigonometr y right-angled triangle. b 3 cm 7 use each a measurements ● of in 2 Find triangles x in cm each 6 cm 14 cm triangle. a b 7 cm x 8 cm 5 cm 62° x ● nd of a the area of a sector 3 Find the area of this sector. circle 115° 6 ● use radians 4 Find x in each cm sector. a 2 Area = x b cm 14 1.7 cm x rad 8 5 Area F of a rad cm cm triangle A ● How can you nd the area of a non-right-angled convention practice ● When label with How working vertices a with and capital does area triangles, the letter, the interior and the formula the you convention angle side help at each opposite is nd the area of other shapes? with Practice the same letter in lower case, to things vertex Here are easier everybody this: it. For follows example, in algebra, the convention 1 triangles remaining ABC, DEF, LMN and UVW. Copy each vertices and triangle sides. F c d A E b L u M v 18 4 is to a and variables E9 Space in label alphabetical the makes if c write 1 usually essential, A that like a which, although not b vertex is triangle? order. G E O M E T R Y Reect Here of is this and Paco’s discuss calculation A N D T R I G O N O M E T R Y 1 of the area triangle: 5 1 cm 1 2 Area = × base × height = × 2 5 × 10 = 25 cm 2 ● What ● Will ● What mistake has he 10 made? cm 2 It would the true other be answer be greater information better if Paco or might had less help than you remembered 25 to the cm ? How calculate area do the formula you true know? area? as 1 Area = × base × perpendicular height. 2 In mathematics, ‘height’ Exploration 1 A triangle a Use means sides 13 trigonometry of the cm height’. 1 has length ‘perpendicular the cm to and work dashed line, 15 out cm. the which meets 13 b 15 Hence side nd the at right area of angles. the triangle. 47° 2 Triangle AC = 22 ABC cm a Sketch b Hence has and sides BC ∠ ACB triangle = = 7 cm, 42° 15 ABC 2 3 A nd triangle By the has area sides considering the a, of b the and length of triangle in cm c : A the line through A c b perpendicular to BC, of in terms the and triangle the size of angle nd of a formula the for lengths a the and area b C a 4 Use your when BC formula = 10 cm, from AC step = 5 3 cm to show and that ∠ ACB = 30°, the area of triangle 2 ABCis 12.5 cm Tip In Exploration nding its formula 1 length to solve you and found then problems the area deriving than to of a a triangle formula. draw in It extra by is drawing usually lines. an altitude easier to use and the An to a Area of a triangle altitude line one side triangle passes three E9.2 Mapping the world of that the vertex. height triangle its a through opposite The is perpendicular is of a one of altitudes. 18 5 Reect ● What ● Where ● How Use is the would the discuss measures Practice 1 and do you angle you in 2 need to relation change the use to this the formula new area formula? sides? for a triangle that is not labelled ABC ? 2 formula to nd the area of B a each triangle. Give your answers to b 3 s.f. K c 36 m 34° 8 cm 18 58.5 m km E 60° 72° C A 12 L cm J 34.8 2 Find the area of each triangle to the nearest A a square km centimeter. E b 126 cm D 140° 84 56 cm 124° B In triangle Sketch 4 F C 48 3 cm Here the is a cm PQR, PQ triangle = 34 and triangular cm, PR hence = nd 67 its cm and area ∠RPQ correct to = 3 120°. s.f. tile. 20 cm 120° 15 a Find the area of the cm tile. 2 b A to tiler the divides nearest i Explain what ii Explain why Problem 5 In triangle Sketch 6 A 10 large the The of paint 18 6 this it DEF, d = triangle is the area calculation likely side 12 and cm, to 8 m. how Maria on many e = hence tetrahedron thickness Determine by of one tile and rounds up number. be represents. an underestimate. solving regular triangle m whole has is each tins E9 Space 18 cm, nd four going area faces, to surface of its ∠ E paint 49º be Maria and correct each paint will = all 1 of 3 which four mm. to ∠ D faces Paint should buy. = 30º. s.f. is of is an equilateral the sold tetrahedron. in 1.5 liter tins. G E O M E T R Y Reect and discuss Triangle A N D T R I G O N O M E T R Y 3 2 130° 50° 12 ATL ● Find ● Explain ● How the area why does of Exploration In this areas 1 A relate some 2 to cm 1. has the the same area trigonometry as of Triangle the unit 1. circle ? 2 Exploration, of 12 Triangle Triangle this cm other parallelogram use the formula shapes. has Give sides 20 Area to answers cm and correct 45 cm. to Its 3 help you signicant acute angle is nd the gures. 75° B C 20 cm 75° A D 45 2 a Copy b Explain c Find d Hence An the a Write b Hence a. s a a and line segment BCD are BD identical. parallelogram. side value for length of the formula sin area to a 60° of nd an the equilateral area of an triangle with equilateral triangle show hexagon that the can area be of divided a into regular identical hexagon equilateral with side by logo is a sector OAB of a circle with A radius 4 cm and side cm. regular given company 4 the ABD the has exact your length ABD of formula Hence is area the draw triangle triangle Use how triangles. length nd of the down side Explain A nd and triangles area equilateral with 4 why the length 3 diagram cm center O, a portion of which B is shaded. 4 a Find the b Explain c Hence d Find area why of the ∆OAB sector is cm 60° OAB equilateral. O nd the the area area of the of ∆OAB shaded segment. E9.2 Mapping the world 18 7 The area familiar how to formula shapes. divide Area of a for The a triangle key shapes can results into be are simple used given parts parallelogram with below, than to Area of other but results it is more memorize an to nd the areas important to of learn theseformulae. equilateral triangle a θ s b Area = ab Area of a Degrees: sin θ Area = segment Area = r θ r Radians: Practice Give 1 Area 3 answers Find the = correct shaded to 3 areas. signicant The a gures central angle unless is otherwise given in directed. degrees. b c In 1b, two there parts to are the 220° 32° 63° 2 6.2 11 2 Find the total cm shaded areas. The a central angle cm is given in radians. b 7 cm cm c 0.2 9 cm 2π 0.9 13 cm 3 Problem 3 Find the solving area of each shape. a b 7 c cm 28° 9 cm 35° 35° 2 4 m cm 62° 35° 8 cm 5 11 18 8 E9 Space cm m area involved. G E O M E T R Y A N D T R I G O N O M E T R Y 2 4 A segment of a circle has radius 7 cm and area 2 cm 2 7 Find, correct to two decimal places, the central cm 2 cm angle ? of the segment The C in radians. sine and ● How is the sine ● How is the cosine Exploration cosine rule related rule rules to related the to area the of a triangle? Pythagorean theorem? 3 A c b a You have already 1 Explain 2 Hence 3 Show 4 Use why show the that triangle’s that similarly your shown this area can has also be area found using . that formula triangle . from step 3 to show that cm in the triangle below. C 16 cm a 38° 24° B 5 Show 6 Hence A that nd . the size of the acute angle at B in this triangle: A 12 9 47° The For sine a rule triangle ABC A : c b and a E9.2 Mapping the world 18 9 Example Find the correct 1 value to 3 of a, giving signicant your answer gures. a 11 cm 60° 40° b = 11 a cm Label the triangle. 60° 40° A B To nd sine ⇒ a rule missing with side, sides use ‘on the top’. cm Example Find the nearest 2 size of ∠B correct to the degree. 7 cm 13 cm 65° B b = 7 cm a = 13 cm 65° Label the triangle. A B To = B 0.488… = arcsin (0.488…) = 29° (to 19 0 the nearest degree) E9 Space nd a missing angle, use the sine rule with angles ‘on top’. G E O M E T R Y Practice 1 Find the A N D T R I G O N O M E T R Y 4 length of a the sides marked with b A letters, correct B to 3 s.f. c A A 40° 5 cm 110° 63° c 14 42° cm 11 cm C 33° b 33° B B C a C 2 For each triangle, nd the B a 14 size of b cm the 20 unknown angle, B cm to the nearest degree. c B 17 cm A C 80° C 70° 10 20 15 cm cm cm 68° C A A 3 Find the value a of 5 x for each triangle. Give each answer b cm correct to 1 d.p. c x 58 x 7 x 12 cm cm 11 cm 81° 38° 4 In triangle XYZ, Problem 5 A yacht After 6 x = 16 crosses the 2.6km, another b Calculate the size c Calculate the total diagram point moving on sights X, a a Sketch b Determine c Calculate inkm, a A to ship bearing the a ∠ Y = of the show 44º ∠CBA sights of the to and ∠ Z = 72º. a is race B due of the by on Find the length of side y L 10km/h. by of yacht on a time illustrate this information. 3 all three from angles point signicant Y in to a the the the a bearing of 335º of until 026º. it yacht. ∠CAB correct bearing to of minutes this of on bearing bearing Thirty on sails a C size the lighthouse at and followed nd sailed C sails north path and at and again, distance to a 020º of buoy the distance size accurate a which lighthouse triangle line rounds buoy Sketch and a starting it a From cm, 42° solving sailing reaches cm 37° cm of 3 s.f. 350º. later it The is at ship is point Y 325º. triangle. lighthouse. Give your answer gures. E9.2 Mapping the world 19 1 Reect Explain and why discuss you cannot 4 use the sine rule to nd length x in this triangle. x 10 cm 120° 8 Exploration 1 a Copy 4 triangle angles at cm ABC, point with the altitude through C meeting AB at right P. C A B P Label the b Label length c Use show Expand d Use e Hence For why B the cosine a the b as and x. it c Hence theorem label to length write two PB terms of for c and x CP. . and to simplify express x in this equation terms of A as and far as possible. b that is possible to rewrite the formula from step 1e so that it as formula so that it uses angle C A rule triangle in expressions that brackets show angle Rewrite The AP trigonometry Explain uses a, Pythagoras’ Hence 2 sides ABC : c b a Reect ● How the ● does discuss the How would wanted How 19 2 is the required you to 5 information information you ● and modify use cosine the required to the use E9 Space rule related to use the formula: formula cosine rule the to to the if the nd cosine Area = triangle the rule is ab sin C labelled measure Pythagorean compare of side theorem? to ? MNP and p ? Explain. G E O M E T R Y Example Find the 3 T R I G O N O M E T R Y 3 length of side a correct 4 to A N D signicant gures. cm 80° 6 cm a A c = 4 cm 80° b = 6 cm B Label sides and vertices. a C Use ⇒ a = 43.665... = 6.61 Example Find the the cm s.f.) Check that your answer cosine seems rule. sensible. 4 value nearest (3 the of x correct to degree. 132 65 cm cm x 98 cm B a = 132 cm Label sides and vertices. c = 65 cm x C A b = 98 cm Use 17 424 12 740 = 9604 + 4225 cos x = −3595 cos x = −0.28218... x = arccos = 106° ( (to 12 740 cos x the cosine rule. Rearrange. 0.28218...) the nearest degree) E9.2 Mapping the world 19 3 Reect discuss 6 ● Show ● Which version do you think is easier to use to nd an unknown side? ● Which version do you think is easier to use to nd an unknown angle? ● Does that it Practice 1 and Use the the cosine matter rule which can version rearranged to use? 5 cosine rule to nd the lengths A a you be of the marked B b sides correct to 1 d.p. A c 6 75° 4 30 B 25° c 14 12 a C 140° C 35 b A B 2 Use the nearest cosine rule to nd the size of the marked angles correct to the degree. A a B b D c 13 B 12 15 14 27 21 20 C 5 C A 18 3 4 Find these side a ∆PQR, p = 14, b ∆DEF d = 6, c ∆XYZ, x = 7.2, d ∆BCD, b = 25, Two for boats 13km, a q e leave the = = z c = = the b Find the angle c Find the distance triangle f = 5.4, 31, on Draw A R d same other diagram and 11, 12, a Problem 5 lengths a angles, = 98°. 9. Y = 34. illustrating their between y for 8 on a bearing km. positions. courses. the two boats. solving has sides of length 4 a Find the size of the largest b Find the size of the smallest 19 4 their s.f. D travels 135º 3 r side angle One of to E Find Find harbor. side angle 121°. bearing between Find Find = accurate E9 Space cm, angle 6 cm in angle and the in 7 cm. triangle. the triangle. of 060º C G E O M E T R Y Applying D You can ● Which ● How use triangles. the To the Referring do to the sine useful, dene and are rule trying triangle rules to to discuss the and sine ‘where’ cosine which you and more we sine decide information Reect is the rule and to use, cosine or the A N D T R I G O N O M E T R Y rules cosine rule? ‘when’? nd look missing at the lengths and information angles you in have and nd. 7 here: 9 7 ● Which measurements can you calculate? 38° What rule ● What information ● What By should parts, so the use only sine each two use? rule: b to leads rule be you and For shown 2 = a Explain needs one. are 2 Cosine you information examining you will your given to in use cosine the sine selection. order the rule to be cosine you to use the sine rule? rule? carefully, rule, able you only ever can use work two out of when the three here. 2 + c 2bc cosA Sine rule: 21 17 x 17 Tip 19 50° If an angle and the 30 x side opposite known, The cosine rule involves three sides The sine rule involves two one angle. and two rule triangle sides so and use the problem one cosine Example Find the angle involves (the three This unknown), sides rule. can be angles. used. This the sides sine and then are triangle and problem two unknown), so angles use involves (one the sine is two use If the not, then cosine rule. the rule. 5 size of the angle at A A 10 5 26° B C The C ⇒ A = arcsin(2 sin 26°) = 61.25 = 180° = 92.7° − 26° (3 − 61.25° problem involves two sides and two angles, Rearrange The angles in a to so use make triangle the C sine the add up rule. subject. to 180° s.f.) E9.2 Mapping the world 19 5 Practice 1 In each used 6 triangle, to nd the determine value of x. x a whether Explain the cosine how you rule have 4 b or sine made rule your should be decision. c 19 x 11 7 21 52° x 12 10 2 d e 47° f 12 15 140° x x 47° 16 x 15 45° 8 2 In each triangle, nd the value of x, giving a your 62 b 7 answer to 3s.f. cm cm 78° 11 correct 130° cm x 30° x c d 4 172 88 cm cm cm x x 6 240 cm cm 40° 78 e cm f x 130° 45 cm 14 35° cm x 11 3 Use the Give a sine rule answers 17 or cosine correct to 3 cm rule to nd signicant the marked sides and cm angles. gures. b b 5 c cm 57° 4 cm 110° 12 6 a cm cm c 10 42° d 8 cm 30 e cm f 11 cm 47° d 9 e cm 19 f cm 57° 61° 19 6 E9 Space cm G E O M E T R Y Problem 4 Find the A N D T R I G O N O M E T R Y solving area of this triangle. 2x x 1 1 120° x 5 Circles of radius 10 cm and 6 cm overlap as + 1 shown: A 10 cm 6 cm O B C The circles meet Find b Hence nd ∠ABC c Hence nd the handy length and measurements Objective iv. In justify the that ATL points a One the at D: the of the in space and straight C, line of you mathematics degree accuracy inaccurac y comment in the segment trigonometry can’t Applying Activity, ∠AOC = 0.8 rad. joining A to C area. use that of and radians. shaded benecial in A on the original of is measure a accurac y in to help you calculate directly. real-life contexts solution of the measurements original would measurements have on your and the e ect calculations. Activity 1 Telephone cables from a house are connected to a telegraph pole C at the roadside, but C is not yet connected to the network. Continued on next page E9.2 Mapping the world 19 7 On the other side of the road, two other telegraph poles A and B are A 30meters theodolite tool An engineer uses a theodolite to measure ∠ CAB = 27° and ∠ ABC = used maps Copy and complete this aerial view of the street, adding the to a measure 68° angles a is apart. size when or surveying of construction angle B and the length making sites. AB C b Find the c Hence d actually Calculate ii Find iii Suggest From It 2 the this b Calculate c Find the boats other the ship km distance leave on a size a a c Find the distance diagram Alex of and 113º. the I standing and C AC 27° should A B in the measurements. The angle at A Justify your the to your original engineer connect B degree calculated should to of bring accuracy. value of BC more cable C on R of on a angle from to one 145º between point Q bearing on of a bearing of 039º. 072º. diagram. P travels for 18 their their between to a PQR. illustrating Mary Mary distance at I am are on a bearing of 050º for 14 km, km. positions. courses. the two boats. is sea-kayaking. on between point markers R. of km R solving Find Q and at BC. in why value 5.5 harbor: angle P, of error point bearing the are BC error length sails information Find am an reasons to b there true calculated Draw bearing 4 discovers a Peter, of pole B. percentage the Problem 3 a 4.1 Show the pole three the P, sails a Two to lengths telegraph 7 point then the C 23° i Practice angle the engineer than 1 why connected The is of calculate Explain be size O, every 20 m a bearing Peter near 100 a m. away of and can from 210º is 430 and a m from distance Alex of 310 on m a from Alex. Mary. major I Peter road. see Along three marker P. the road consecutive The bearing markers: of P from R my current position is position is 340° and the bearing of Q from my current 030° Q a Find the angle POQ b Find the bearing c Find my distance from Q d Find my distance from R of Q from P P O 19 8 E9 Space G E O M E T R Y A N D T R I G O N O M E T R Y Summary When working opposite with vertex A a and triangle so ABC, side a The is sine rule on. A and c b a Area of Find cosine rule triangle Mixed 1 The practice the shaded areas correct to 3 s.f. 3 Find the angles a areas are of given these in segments, radians. Give whose your central answers b correct 4 to 3 s.f. cm 9 cm 110° 50° a 7 b cm 15 cm 2.1 c d 0.3 7 11 cm cm 50° 11 cm 4 Find the labelled side correct to 3 s.f. 120° a 7 cm b 20 cm 42° 5 5 15° 130° cm 34° cm 8 e d cm f 42° c 7 cm 50° 19 40° 6 cm 9 73° cm 7.2 cm 11 cm cm e f 42° 8 cm 108° 110° g 15 21 5 cm 24 cm cm cm 7 cm 3 cm 62° 5 2 Find the areas of these segments correct to 3 Find the labelled angle in degrees, correct 3 s.f. s.f. a 9.6 8.2 80° a to cm cm b b 14 6 20 cm cm 47° cm 115° 57° 9 18 m 15.4 cm d 18.2 6 cm m c 11 m 25.9 E9.2 Mapping the world cm 19 9 cm 6 Find the labelled angle in radians, correct to 3 s.f. 8 Two One 14 friends walks start 50 walking meters due from the north. same The spot. other walks cm 35 8.2 meters on a bearing of 057° a 11 cm 14.7 Find 1.2 19 cm the correct distance to 3 between their nal positions, s.f. b Problem 11 solving 14 cm 9 c Find the perimeter of this triangle, correct to d 7 3 s.f., given that 2.1 18 15 cm 15 cm 2 Area 7 Find, in degrees, the size of the smallest angle = 180 cm in x a triangle with sides 4 cm, 9 cm and 11 cm. 27 ATL Review Many maps Surveyors in are underpins Use the these created map the on questions. sensible context measure that degree map, the as next Give of by triangulation; distances and illustrated page your to this bearings you when a in this here help answers is to high answer correct to a network degree of b a It is 9.5 km from of 076°. bearing of 130° a from Using three their 20 0 the Rolle to Saint-Prex Thonon-les-Bains from Rolle, and on of Find the are and joined use Hawaiian and label ∠ STR and Hence nd lies on a Prex a on a d bearing the across them to island size of a form of landscape. the skeleton Oahu. angles ∠ RST, ∠ TRS letters R, S sketch positions and the from distances Rolle to from Rolle to Saint- Thonon-les-Bains. When standing in Saint-Prex, there is an angle of 100° between Lausanne and Thonon-les-Bains. Saint-Prex. towns, points accuracy. bearing of170° of accuracy triangulation c 1 cm Lausanne lies on a bearing of 038° from Thonon- and T triangle relative E9 Space to to denote RST each to other. les-Bains. Add this information to your diagram. the show e Hence nd Saint-Prex the and distance from Lausanne Thonon-les-Bains. to G E O M E T R Y The map border lake below and itself, places on is shows known and the the some as key Lake mountains shores of the towns Geneva that lake is on in the most surround banks of Lac Leman, English-speaking it, nding which countries. point-to-point lies A N D on Because distance the of T R I G O N O M E T R Y French-Swiss the presence measurements of the between dicult. Lausanne Saint-Prex Vevey Rolle Montreux Evian-les-Bains Saint-Gingolph Thonon-les-Bains Yvoire Coppe Chens-sur-Leman Geneva Problem 2 The 3 solving distance from Evian-les-Bains to The distance from Vevey The distance from Montreux is measured to be from between Viewed of 66° Lausanne, Evian-les-Bains from there and Lausanne is an angle of and there isan a 9.6 km. lies on a The is distance 8.6 km Find the angle on from a Vevey bearing between Saint-Gingolph angle 6.5 km. of to Saint- 200° as Montreux viewed from and Vevey. Saint-Gingolph. b Evian-les-Bains is Saint-Gingolph 54° Saint-Gingolph. Evian-les-Bains, between to 16.9kilometers. Gingolph Viewed Montreux Saintis Gingolph to bearing of 200° Hence nd the bearing of Montreux from from Vevey. Lausanne. c a Find the bearing of Saint-Gingolph Find the bearing of Saint-Gingolph from from Montreux. Lausanne. 4 b Find the distance from Lausanne to Nyon is 7.0 km from Chens-sur-Leman. Coppet Evianis 6.1 km from Chens-sur-Leman. As viewed les-Bains. from Reect and How you have Chens-sur-Leman, between Nyon Find distance the and there is an angle of Coppet. from Nyon to Coppet. discuss explored the statement of inquiry? Give specic examples. Statement of Inquiry: Generalizing in space can and help applying dene relationships ‘where’ and between measurements ‘when’. E9.2 Mapping the world 2 01 84° Time for a change E10.1 Global context: Objectives ● Drawing Orientation Inquiry graphs of logarithmic ● functions in space and time questions What does a logarithmic function F looklike? ● Finding ● Justifying the inverse of an exponential function ● algebraically and graphically How are logarithmic toexponential a logarithmic S P I H S N O I TA L E R exponential function function and are the Identifying and transformations applying on inverses of What are the properties of logarithmic C function graphs related functions? corresponding mutual ● ● functions that functions? logarithmic ● How are the properties of logarithmic functions functions related to those of exponential functions? ● How do you transform logarithmic D functions? ● ATL Is change measurable and predictable? Critical-thinking Draw reasonable conclusions and generalizations E6 1 E10 1 E12 1 Statement of Generalizing relationships and 20 2 Inquiry: changes that variability. can in quantity model helps duration, establish frequency N U M B E R Y ou should already know how to: x ● rewrite exponential logarithmic statements statements and as 1 vice Write y = 5 as a logarithmic statement. versa 2 Write y = log x as an exponential 7 statement. ● nd the inverse of a function 3 Find a the f (x) inverse = 3x + of the functions: 2 2 b ● describe transformations on 4 g (x) = x Describe 1 the transformations on x exponential functions the graph of y = 3 that give the x graph ● justify algebraically graphically are mutual that and two 5 functions y of Justify = 2 × 3 -1 algebraically graphically that the and function 5 inverses f ( x ) = is its own inverse. x F From exponential to logarithmic functions ● What ● How Objective ii. In in B: describe to are Fold 1, solve an of the will functions need to r ules look related like? to exponential functions? nd consistent the correct with rules ndings for the patterns you generate problem. 1 piece of paper thickness of the folded function patter ns general given size the as you the A4 Assume logarithmic logarithmic patter ns Exploration 1 a Investigating Exploration order does paper is 0.1 in half. paper is You 0.05 now mm. have The two total layers. thickness mm. A4 of size the paper standard thickness = 0.05 used Fold the paper in half layer again, 3 Find the 4 total a thickness function number Write terms down of the of a f of for folds the the most around world. the two mm In and Canada, size is the USA the ‘Letter’ standard, layers and write down the number of layers folded paper. number of Repeat layers of once the 8.5 by and 11.0 the in countries measuring 2 part mm 0. 1 one is international inches. more. folded paper in terms of x function number of g for folds the total thickness of the folded paper in x Continued on next page E10.1 Time for a change 20 3 5 Use a 6 function 10 Use a 7 10 a 8 It ● area Do you In folds of Why the think times? 2002, a the ● her Britney of folded nd ● For in 13 at a paper 1 an layers 10 give a total m Moon total after : give : folds the a A4 to thickness d is 384 thickness sheet fold this to fold a a is? number American roll paper, to of of of paper sheet Think folds larger 400 of of in A4 about of the piece This fold shows the mm it 14 that is 1 km. 384 half of : km Determine 400 is paper the km. seven more times. than relationship of paper. of paper more in 1200 thickness, world of record and the for Massachusetts paper thick, long than Gallivan, could be folded , thickness was paper Britney m formula its the the student, paper the t nd held of 0.058 to a school times. length order Exploration the Gallivan the the developed formula students to give think possible that She of to paper 1 you 16-year-old length Use is Earth impossible to 30 many folded folds folds c folding do 30 c how the Explain. demonstrated 12times. from paper it layers needed for many m discuss record times. seven ● distance of c how determine mathematically the 20 1 thickness folds determine to of and world is g total 20 b average seven the b number The to cm Reect ● f layers 10 the nd b function The to folds function Use g 0.058 that was how is the paper showed mm 13 would a where number she until paper Use of half L is folds. used. folding that thick. folded long n paper in the a can group be formula to times. sheet of paper need to be times? the inverse of an 1.1 exponential x function is a logarithmic function. For example, theequivalentlogarithmicstatementis log y = for y = 2 , y x y = x 2 x Interchanging gives the the inverse x and y function in y the = logarithmic log expression y = 2 x 2 x Graphing y = 2 and y = log x together veries that they are x 2 f (x) = 2 f 1 mutual inverses, since their graphs are reections of each 0 in the line y = x x To nd the equivalent inverse of an logarithmic exponential statement function log y = x , y = then a , use the interchange the a x and y to obtain y = log x . The domain of the exponential So the domain a + x function y = a is , and its range is . of + y = log x is , but the range is a 20 4 {0}, since log x a E10 Change ≠ 0. (x) 2 = log x 2 other its inverse x N U M B E R The inverse function. Practice 1 State the of The an exponential inverse function of is the corresponding is and logarithmic vice versa. 1 inverse function of f ( x ). x f a (x ) = 4 b f (x ) = log x c f (x ) = ln x 6 2 3 lnx x f d (x ) = 3 log x f e (x ) = f f (x ) = (11 ) 5 3 4 Problem 2 The solving population of seagulls P in a coastal village can be modelled by the x exponential a Draw equation P ( x ) the graph of P , = 15 × 1.15 (on your where GDC) and x is in state P months. , the initial seagull 0 population. b State c Draw d Using reach the inverse the the graph function. of graphs, the nd ● What ● How are are the the of Exploration 1 Graph long it on would the same take the logarithmic properties properties ofexponential ATL how function for axes. the population to 20seagulls. Proper ties C inverse of logarithmic logarithmic functions? functions related to those functions? 2 function Experiment of functions with and dierent values add of a a > slider for the parameter a 1. 1.1 y 4 3 2 f (x) = log 1 x a 1 0 x 1 2 3 4 5 6 7 8 9 10 1 2 a 2 3 0 10 4 2 a State what happens b State the c State any d State whether domain to and asymptotes the the value range of the function of of the y as a increases. function. function. is concave up or concave down. Continued on next page E10.1 Time for a change 20 5 3 e Does f Determine g Explain Graph the the x-intercept if why the x remain function cannot be the has less function a same all y-intercept. than for for or equal dierent values of a ? Explain. Explain. to 0. values of a, where . 1.1 y 3 a 2 0 f (x) = log 3 1 x 0.3 1 x 0 4 3 2 1 1 3 2 4 1 2 f (x) = log 2 x 0.5 3 4 a State b Repeat Explain alike, 5 what steps how and happens b–g graphs how Summarize 2 they your to the for of value this of results as a increases in the interval (0, 1). graph. logarithmic are y functions with dierent bases are dierent. in a table like x this: y = x a y = log a domain range equation of asymptote intercept(s) Properties of graphs of logarithmic functions y y y = log x ; when a > 1 y = x x A logarithmic ● domain All graphs x-intercept function and is its 0) and of the range logarithmic (1, when 0 < form is < 1 functions vertical , where . . of the asymptote x form = have 0. Continued 20 6 a 1 is of ; x 0 1 Its x x 0 ● log E10 Change on next page N U M B E R ● The shape graph is concave ● The Find the domain the graph is concave down and up value Example of and of a determined by increasing. the For base 0 < a. a < For 1, a the > 1, the graph is decreasing. controls how rapidly the graph is increasing or decreasing. 1 inverse and of range and of the function verify and its your result graphically. State the inverse. Interchange Rewrite as a the x and logarithmic y variables. statement. 1 Graph f and f and conrm that f and Graphically: 1 f are reections of each other in y = x. 1 Since in f the and line f y are = x, reections they are of each mutual other 1.1 inverses. y Domain of f Domain of f range = of f f (x) = log 2 x + 3 2 1 = ; range of . x f (x) = 3 2 1 x y Reections every type echoes are and of and sonic observed light, which iii. In move C: with of can many are properties think of. studied types produces reection of in well known study acoustics; and electromagnetic beautiful can are Geologists also and mean x the act of wave, interesting of for just seismic about waves; course, reections including images. peaceful visible Perhaps not meditation. Communicating between Exploration forms physical you eects often coincidentally, Objective their wave = 3 dierent you logarithmic will forms move of between mathematical graphs, tables representation and equations, and dierent functions E10.1 Time for a change 207 Exploration 1 Here is values. the 3 graph Explain of a how logarithmic you can nd function a using , the table of with its table of values. 1.1 1. 0. y 2. 0.63093 3. 1. 4. 1.26186 5. 1.46497 6. 1.63093 7. 1.77124 8. 1.89279 9. 2. 10. 2.0959 1 0 2 x 1 1 2 3 4 5 6 7 8 9 10 1 2 2 Copy the 3 Identify allow 4 the graph function. Use the you what from Draw step the coordinates to nd you a in learned 1. Explain graph on of the its how you inverse graph of can draw the inverse of inverse that function. the function and its both. in steps 1–3 to nd a in this graph of . 1.1 y 4 2. .5. 3. 1. 4. 1.58496 5. 2. 6. 2.32193 7. 2.58496 8. 2.80735 9. 3. 2 0 x 2 1 1 3 4 5 6 7 8 9 10 2 4 5 10. Approximate . the State value what of you a from think this the 3.16993 graph exact and value table of a of values might be. for Explain. 1.1 0. 1. y 4 2. 0.693147 3. 1.09861 4. 1.38629 5. 1.60944 6. 1.79176 7. 1.94591 8. 2.07944 9. 2.19722 2 0 x 2 1 1 2 3 4 5 6 7 8 9 10 2 4 10. 6 Explain function 20 8 an easy way to determine from its E10 Change graph the or 2.30259 unknown table of base values. of a logarithmic N U M B E R The graph Practice 1 Match a f of = through the point (a, 1). 2 each ( x ) passes graph log to its function. x b f ( x ) = log 2 x c The C y 4 3 3 3 2 2 2 1 1 1 0 x 2 5 x 1 1 2 0 5 2 5 1 1 2 2 2 3 3 3 4 4 4 shows function y the year. = log height The in height meters data of can a be silver maple tree, approximately measured modelled by at x 1 1 each x B 4 1 of log 4 table end = y 0 2 ( x ) 0.3 A y 2 f 5 the the x a Age of tree 1 2 3 4 5 6 7 8 9 10 0.1 3.5 6 7.5 9 10 10.5 11.5 12 12.5 x (years) Height y (meters) a Plot b Find c Conrm you 3 Each these the inverse on of in a graph this graphically found graph values and function, that the estimate and the state function in b its is value of domain the a and inverse of range. the function a below represents a function of the form f ( x ) = log x. a For each graph: i state the natural ii state the base of domain the and the logarithmic range 1 0 x 1 1 2 3 4 5 function y 2 1 the function. y 2 of 2 3 4 5 2 1 1 0 2 y 2 1 x 0 2 x 1 1 1 1 2 2 3 3 4 4 5 5 E10.1 Time for a change 2 3 4 20 9 5 4 For each i state ii nd function the the natural inverse function iii in domain of order the for conrm graphically original function. x a f (x ) f d = (x ) + = Explain and 2 − range function, the that the of and inverse to the function state be function a any domain restrictions on the function you found is the inverse of the 2 e Problem 5 below: log (3 x − 2) b f (x ) = e f (x ) = 3 log ( x + 2) f c (x ) = 4 log (1 + 2 x ) ln( 2 x ) − 4 solving how logarithmic the change function of of base the property form y = log of x logarithms can be ensures expressed in that the every form a y 6 = For b ln x each description below, write down a function with the given characteristics. + a A logarithmic b An function, passing through (1, 0) and (4, 2), domain = 1 exponential function whose inverse is f ( x ) = 2 log x + 7. 5 c A logarithmic function, passing through (5, 1), (1, 0) Transformations ATL ● How ● Is do change Exploration 1 2 State the a f ( e f ( x you measurable eect of each b h ) a logarithmic logarithmic and 25 functions functions? predictable? 4 x ) Using transform of , 2 D 1 and f graphing the same eect the transformed transformation f f ( x ) tool, on the ( x ) + c k verify graph on af the graph of f ( x ). ( x ) d f (ax ) g that of y the = transformations log x. Draw a in graph step of f 1 ( x ) have and 4 Summarize 3 Conrm graph your your to results results demonstrate in with a what you have discovered. table. another function of the form y = log x a 4 For each aects 21 0 of the transformations (domain, range, in x-intercept, E10 Change step 1, indicate asymptote) which and how. property it N U M B E R Transformations of exponential functions Reection: For the logarithmic ● the graph of ● the graph of y function = : is the reection of y = is the reection of y = in in the x-axis. the y-axis. Translation: For the logarithmic ● function : translates by k units in the When k > 0, the graph moves in the positive When k < 0, the graph moves in the negative ● translates by h units in y-direction. y-direction y-direction the When h > 0, the graph moves in the positive When h < 0, the graph moves in the negative (up). (down). x-direction. x-direction (to x-direction the (to right). the left). Dilation: For the logarithmic ● function is a vertical is a horizontal : dilation of scale factor a, parallel to the y-axis. ● dilation of , scale factor , parallel to the x-axis. af ( x ) f (ax ) y y f (x) = 4log x f (x) f (x) = = log(3x) log x f (x) x 0 vertical dilation scale factor y log x x horizontal 4 = 0 dilation scale factor y f (x) = log x f (x) x 0 = log x x 0 1 f (x) = log x 1 4 f (x) = log 3 vertical dilation scale factor horizontal dilation scale factor 3 E10.1 Time for a change 21 1 Example Describe 2 the transformations on to to in the negative is a translation factor Practice 1 f (x ) f the = (x ) is transformations log x ; g (x ) = log f = (x ) log x ; g (x ) = log f (x ) = (x f (x ) outward from the variable. a vertical dilation, = to ( x ) to get g ( x ). - 3 ; g (x ) = log (6 x ) - 4 2 x ; g (x ) = - 4 log (x + 2) + 8 5 2 log (x + 1) - 5 ; g (x ) = 6 log 3 Problem f - 7) + 1 x 5 e Work 8 x log applied = 2 log 2 d units 4 8 c 4 3. 4 b of 3 Describe a . x-direction. to scale get (x - 4) + 2 3 solving 2 f f (x ) = log x ; g (x ) = log (3 x + 12) - 10 7 7 3 2 Describe a g (x ) c j (x ) the = = e m( x ) g p( x ) transformations ln ( x applied to - 3) + 2 ln ( 2 x ) - 1 = -3 ln ( x + 1) f (x ) = ln x to give: b h( x ) = 0.5 ln x - 1 d k (x ) = 2 ln x f n(x ) = ln (0.5 x ) + 2 + 1 1 = -2 ln(5 x ) - 3 q (x ) = h ln(2 x - 6) + 4 5 3 Each For graph each function shows one, in an original describe terms of the function f ( x ), labelled transformation(s). Hence A, and write transformed down the function, equation of labelled the B. transformed f y y a y b c 1.5 2.5 4 B A 1 2 3 B 1.5 0.5 A 2 1 0 4 2 2 0.5 1 x 4 6 A 0.5 0 1 0 x 2 1 x 2 2 4 4 1.5 0.5 2 B 1 2 1.5 2.5 3 4 Problem solving 4 Draw the graphs of f (x ) = lnx and g (x ) = ln 1 2 x 2 Describe 5 Draw the the transformations graphs of f (x ) = on log x the and graph h( x ) of = 5 of axes. 21 2 Describe the transformations E10 Change f on the same give the graph - that - log set of axes. [5( x + 2 )] on the of g same set 5 on the graph of f that give the graph of h 4 N U M B E R Summary A logarithmic function is of the form + where range is ● , the graph of y = is the reection of + , . , Its since domain x is cannot and take the its y value = in the y-axis. 0. Translation: The inverse of the inverse of an exponential For function is the corresponding logarithmic the logarithmic ● The inverse of is translates When of logarithmic All graphs of logarithmic functions of the k > 0, asymptote x The of x-intercept (1, 0) and = shape and a. For the is > graph up value of a graph point (a, the For and increasing The 1, increasing. concave The a is determined by graph 0 < a < is 1, concave k the graph When is < 0, how rapidly the When graph of h Match a y = > 0, h < passes through the (to 0, x-direction moves in the negative by h units in the the (to graph in the positive in the negative right). graph the moves moves left). Dilation: the of logarithmic the logarithmic is factor function of in is ● : the the function : functions reection b, a vertical parallel is scale 1 graph 1). graph Mixed the (down). x-direction decreasing. logarithmic = positive x-direction. ● y the down Reection: the in translates decreasing. controls or Transformations ● moves the For the graph 0. the base the vertical ● For in (up). y-direction ● units form When have ● k functions y-direction ● by y-direction. versa. Graphs ● : and the vice function function. factor a to dilation the horizontal parallel of scale y-axis. to dilation the of , x-axis. of x-axis. practice the log function with its graph: x b 5 y = log (− x ) c 5 0 = log x 0.5 A B C y y y 1 y x 0 x 1 E10.1 Time for a change 0 x 1 213 2 While training average speed for for a a race, 10 Joseph km run. tracks The his 4 data, Describe change the the transformation(s) graph of f (x ) = necessary log x into the to graph a shown in the table modelled by where speed the below, function can s = be log approximately of w the + 14, the given same. function, Where assuming more than the one base remains transformation a s = and w = week of training. is needed, correct Week Speed make sure you write them a order. y = log x + 2 b y = log 5 14 2 14.88 c y = e y = g 15.76 y = - 2) - 3 x d y = ln (- x ) + 2 f y = ln (2 - h y = 2 log 16.04 6 16.27 7 16.47 8 16.64 i y = -2 log (- x ) Sketch g (x ) 9 = the -7 10 16.92 Explain for - 2) - 1 x ) + 2 solving graphs ln (3 x of f (x ) - 12 ) + 1 = on ln x the and same set of axes. 16.79 Describe a (x 8 -2 l n (1 - Problem 5 x ) 4 3 5 + 2) log (x 7 ln (x 15.39 4 the (km/h) 1 3 in this why kind a f logarithmic of model is a good t 6 to give Sketch the the the transformations graph of g graphs of f (x ) = on log the x graph of and 1 data. g (x ) = log (2 - x ) on the same set of axes. 4 b Plot these values on a graph and estimate the Describe value of give c Find the inverse of this function. State that the inverse function the each function in parts a to of on The data in the the table form y here = a follow + of f to the natural domain an exponential k e: 1 state graph x of x i the g represents. model For transformations graph the 7 relationship 3 the a and range of 3 0 1 2 the 2 function y ii nd any in the inverse domain order for of the given restrictions the inverse on to function, the be a and original 4 conrm found graphically is the a y = ln ( x b y = 5(7 c y inverse that of the the - 3) 0.2 x ) + 2 1 = log (4 x - 8) - 5 2 2 log (x + 1) 2 d y = log 3 2 1 e y 21 4 = x 4 E10 Change function 11 state function original 7 a Find the inverse b Describe of this exponential function. function inverse iii 5 you function. the dierent function. ways you can nd this N U M B E R Review In E6.1 of some here in you explored natural explore considering context the the the logarithmic phenomena. graphs of The these models on their The by r graphs. = Richter pH is calculated using the logarithmic of energy can 0.67 log the 1 amount earthquake phenomena transformations 3 questions E be - 7.6 , scale, and earthquake in released modelled where E is the r during by is the the energy an function number on released by the ergs. formula + pH = - log (H ) a By comparing this model to the standard 10 logarithmic Using transformations of functions, dierence standard 2 The in graphs logarithmic formula for of this model modelling y model = the log f (x ) = log x, describe, describe using the function and transformations of functions: the i x . the eect the graph of the of scale f ( x ), factor and the 0.67 name on of this magnitude transformation M of an earthquake using the Richter scale is ii I the eect of the parameter - 7.6, and the c M = , log10 where I is the intensity of the c name I of this transformation. n ‘movement’ of the earth from the earthquake b and I is the the intensity of the The range for this model is the number on the ‘movement’ n Richter ofthe earth on a normal day-to-day scale, A series of earthquakes were recorded which followed the standard series Explain of earthquakes were recorded which were 4 times of these this the graph the earthquakes of domain of this why the graph State graph Height above can that sea be the of this kind of would give level and modelled is Australia, known Russian this to Reect be and have Give specic you the Describe would using How magnitude double quakes. model model the dier of the how from the the of has no y-intercept. the air function p of the graph of standard the where per h is square measured foot. transformation -26 400 ln in feet, Describe of the 2120 and this graph p in model of y = pounds as a ln x functions. Statement of Inquiry: discuss explored = quakes magnitude transformations examples. a atmospheric by In model transformation functions. h b model. using pressure transformations the intensity. 4 Describe 10. in on Mexico ≤ model. y-intercept. A r in c Russia, ≤ basis. Determine a 0 statement of inquiry? Generalizing relationships and changes that can in quantity model helps duration, establish frequency variability. E10.1 Time for a change 21 5 Meet E10.2 the Global transformers context: Objectives ● Graphing rational Inquiry functions of the form (x ) = + k x Finding technical innovation questions ● What ● How is a rational function? are asymptotes linked to domain h and ● and F a f Scientic asymptotes of graphs of range? rational MROF ● functions How can understanding transformations C of ● Transforming rational functions rational functions help you graph using them? translations, ● Identifying reections and transformations dilations of graphs ● Can ● Does a function be its own inverse? D ● Finding the inverse of a rational function science solve problems or create them? ATL Critical-thinking Revise understanding based on new information and evidence Statement of Inquiry: 10 2 Representing helped change humans apply and our equivalence in understanding a variety of of scientic forms has principles. 11 3 E10 2 21 6 A LG E B R A Y ou ● should nd the already domain and know range of how a 1 to: State function the these domain and range of functions. 2 a f ( x ) = 2x + 5 b f ( x ) = x 2 c f ( x ) = 1 ● write statements of 2 Write propor tionality b transform the statement propor tionality a ● x functions 3 y is y is State propor tional inversely the to x propor tional combination transformations get of for: of applied 2 nd an inverse function 4 Find algebraically x to f ( x ) the −2( x inverse + 3) relation algebraically, whether or also a not the + 5 of and inverse each state relation function. 3 a to 2 g( x ) = , function is x g( x ): f ( x ) = ● to f ( x ) = 2 x + 2 b f ( x ) = ( x − 2) 4 F A ● What ● How rational cables and ( x ) is the is and is this design forces is the of together. g ( x ) on tension is are ≠ 0, real of and so by and a of x, be and reciprocal of real excluding range? expressed g(x) ≠ a quotient 0 function, numbers as is one excluding type zero, of and zero. of the bridge. stable, who opposing the work Clifton spans River set of can and reciprocal layout the domain which the the bridge which the is compression photo Bridge, called engineers that and a the to functions numbers suspension keep bridge Gorge Bristol, a achieved This x linked function domain design help Suspension Avon of any application the used cables Its set function? asymptotes , practical function The f function. range One are rational function rational its a function where The is the Avon, in England. E10.2 Meet the transformers 21 7 Exploration 1 Complete x the 8 1 table 4 of 2 values Use x a the table from 8 Explain b . 1 2 4 8 c In a a you the as x positive draw behavior of gets and y as positive dierent color, draw Find b help happens both the graph of for values a closer to negative x gets and closer negative vertical line 0. Think values and of that closer values on about x your for to what approach 0 on 0. the x graph that the curve touches. why x can function and to about Explain the 1 Think never d step 8. for Describe graph. in to what happens 4 function 2 of 3 the 1 y 2 for the be equal to 0. Hence, state the domain of . values negative Explain never why x for which values for x y of can never be y gets equal to closer 0. to How 0. is Think this about positive represented on thegraph? c In a dierent curve d For ● State a never the ● The Reect ● Find the How of are the 21 8 of x horizontal line on your graph that the function asymptote x for is approaches is discuss the of the graph domain the horizontal positive the approaches equation the the asymptote as and asymptote ● as vertical approaches a function: horizontal approaches draw touches. range reciprocal The color, 0. or vertical (The line negative line that that the graph of f ( x ) innity. the denominator graph can of never f ( x ) equal zero.) 1 horizontal asymptote and the vertical of and asymptotes? E10 Change range of this function related to the equations A LG E B R A Exploration 1 a Copy x and 8 2 complete 4 2 this table of values for 1 1 2 4 8 y b Draw c State the domain d State the equation they e graph Explain g Write in Reect ● > and If eects Graph values 2 Move of the the of Generalize Write 4 for g the and a 1 and and is 0. 8 and 8. function. from for between vertical asymptotes. How do range? of < x of 1. Explain why 3. only which Test Exploration in quadrants quadrants your the 2 and graph conjecture with a 4. of will GDC. 2 is g ( x ) = -f ( x ) transformations f or ( x ) is g ( x ) and f ( = f x ) ( x )? How compare do when 3 10 to to and the explore eect the insert a slider for the parameter a for +10. (positive, why this of , two of quadrants graph and values horizontal conjecture conclusions Explain in discuss slider a the graph function from values 3 a 0, Exploration 1 the range domain only and the ATL your down a of at is for and the why for of to back f be graph relate Look that the what negative, of for case the fraction, parameter when when happens a a > = 0, 0 a and is to the graph for dierent zero). on for the a ignored < in graph of . 0. step 3 y The graph is a of a reciprocal special hyperbola. It case has a of a function curve horizontal called , a asymptote a at x y = = 0. 0 and avertical Because the asymptote asymptotes < 0 a > 0 at are x perpendicular, rectangular it is also known as a hyperbola E10.2 Meet the transformers 21 9 Reect ● and Compare its eect discuss the eect of 3 parameter a on the graph of with on: a linear function a quadratic ( y = ax) 2 ● For y = on f the rational (2x)? the each What graphs Example For function ( y = ax ) function does of this rational , mean is about the the eects same of as these y = f ( x ) or transformations functions? 1 function ● state ● write down ● draw the the a below: domain the graph and range equations of the of the asymptotes function. b a x Domain: ; Horizontal Vertical range: asymptote: asymptote: x y = y = -4 0.75 -2 1.5 0 0 y 1 3 14 6 10 Make a table of values. Draw the graph by 12 plotting several points 6 from the table of values. 12 2 4 2 0 2 4 6 x 2 1 3 6 2 1.5 4 0.75 10 14 Continued 2 20 E10 Change on next page A LG E B R A b x y 0.5 4 Domain: ; range: 1 2 Horizontal asymptote: y = 0 2 1 Vertical asymptote: x = 0 4 y 10 8 Tip 6 8 When a > 0, 2 is 0 5 3 3 in 4 x 1 1 always 5 quadrants 1 and 3. 2 When 1 6 2 1 = a f in x-axis, the reected and always ( x ) is a vertical dilation of f = factor a, parallel to the 2 and (ax) is a horizontal dilation ( x ), f ( x ), scale factor , parallel to y-axis. the a f f x-axis. ( x ) f (a x) y y 1 f (x) = 5 2 x 1 1 f (x) f = (x) = x 5x 1 f (x) 1 2 = 1 x 0 vertical dilation 0 x scale factor 5 horizontal x dilation is in 0.5 function of scale the is quadrants y y 0, graph therefore 4 the < 2 10 For a scale factor Continued on next page E10.2 Meet the transformers 2 21 4. y y 1 f (x) = 1 x (x) f 1 1 5 x = 2 0 x 0 x 1 f (x) = 1 x 1 f (x) = 2 1 • x 5 vertical Reect dilation and ● Explain ● Based why scale discuss it horizontal factor makes dilation scale factor 5 4 sense that the vertical asymptote of is x = 0. Rational on your answer above, what do you think the vertical with will be for the function When does a rational ? function more vertical are ● have two vertical asymptotes? Give Example It takes Model 20 of such Determine beyond 14 situation how days with many a days x = number of students Let y = number of days to eat all rational it the snacks function would take 8 in and a vending the this course. sketch students to its eat machine. graph. all the snacks. Dene ∝ of function. Let y one 2 students this a than asymptote an level example functions asymptote variables. variable is Decide dependent which on the other. ⇒ Identify inverse students When x = 20, ⇒ k = y = 14, proportion increases, the – as number the of number days of decreases. so: 280 Use the the initial constant condition of to calculate proportionality k. ⇒ y 240 When 200 x = 8 (8 students), Therefore, 160 x 120 it would take 35 cannot graph for 80 8students same 40 0 x 4 2 2 2 8 12 16 20 E10 Change number take negative values, so the days to eat the of snacks. is in the rst quadrant only. A LG E B R A Reect ● In and Example number If ● not, In ory what describe them. to 2, a kind how do x each to ● draw a ● draw and value of the domain graph of label and the the x your have take? Does graph maximum reasoning. to or Would Is it possible your graph reect this minimum it make to have represent any this? limitation. values? sense for If so, either x 0? range function asymptotes. 8 = y b 1 = c y length of time it 2 = x x The y your can fractions? change and 4 2 values function: state y of 1 ● a 5 including Explain have Practice For 2, students, Example state 1 of discuss d y = 3x 4 x takes to build a community shelter is inversely A 2016 Design of the proportional to the number of people working on the project. It takes Year 600hours for 4 people to build a to a Model this situation with a rational function and sketch its Determine how long it a would take 12 people to build a all shelter. for 3 Below is the graph of the resistance in an electric circuit (R) at-pack versus which the (I) owing through it for a constant shelter included tools required assembling, and the could current awarded graph. kit b was shelter. be put together voltage. by y four four people in hours. 50 45 40 35 )R( 30 ecnatsiseR 25 20 15 10 5 0 x 0.5 1 1.5 2 2.5 Current a Describe b Find c Hence the the relationship constant write of down between function 3.5 4 4.5 5 (I) current proportionality the 3 using relating and resistance. points current from (I) and the graph. resistance (R). E10.2 Meet the transformers 2 23 just 4 The graph build a models shelter for the number of hours ( y) it takes for aid workers ( x ) to refugees. y 50 40 sruoh 30 fo rebmuN 20 10 0 x 5 10 15 Number From long this it graph, would the 1 person to build the shelter b 5 people to build the shelter c 10 people Newton’s force, a b C the the and law ii acceleration sketch of and ii acceleration motion, versus and How can and 2 24 how = ma, states the relationship between relationship between: mass. the what rational functions transformations of rational functions help them? discuss function on F understanding graph . your explain of : versus y = graph demonstrate Predict hence acceleration Transforming k and mass. graphs force the function acceleration i hand rational shelter. proportional force For workers acceleration. i Reect ● build and you ● to second Describe ● 35 30 solving mass Hence of 25 take: a Problem 5 determine 20 f (x of what happens What 6 h) y you to will = f reasoning. E10 Change k, describe Use mean the be + ( x ). with graph the the eects appropriate an the parameters terms example. of equations of mathematical after of its it is transformed asymptotes? using Explain A LG E B R A Objective i. select and complex In Investigating apply draw state your mathematical new 4 you 2 Use conclusions 3 Set the values graph Describe Set the Sketch 6 Sketch = h and 0 7 a of = 1. 8 the Include of Determine Determine = and your exploration ndings skills clearly to with function 0. a. the discover make new labelled the ndings sketches insert k sliders the at a and for and and eect and h h explore on of and and the negative range. what fraction). graph values of of h. range. k on fractional domain parameters of fraction). and negative, fractional domain the to happens positive, domain time eect what negative, Include (positive, the negative the . one explore positive, of negative state to asymptotes, and the slider (e.g. demonstrate and of the h state positive, eects a demonstrate and to of sliders of positive, graphs and the graph State values to Move values on of asymptotes k the graph values of of k. range. in on the . the , 9 a graphs the k Move dierent several the dierent asymptotes Generalize graph to k. and Include Label graphing Explain values several the use graph eect value for a, for the . Label techniques clearly. to h fractional happens 5 GDC parameters and 4 your the problem-solving 4 the to will conclusions. Exploration 1 patter ns patter ns Exploration and ATL B: horizontal just the by and looking domain and at vertical the range asymptotes of a rational function, function. of just by looking at the function. Reect ● In and Reect discuss and discuss might completely 6, look. correct, 7 you How what were good should asked was you to predict your have how prediction? the If graph you of weren’t predicted? E10.2 Meet the transformers 2 25 The function (the parent The domain Therange The , of of Sketch the the of the the is a transformation of function function horizontal is x = is . is asymptote is y = k . and the equation of the h 3 graph Horizontal rational rational asymptote Example , function). equation vertical where of . asymptote: y = 3 Find Vertical asymptote: x = the asymptotes. 1 y 6 Sketch the asymptotes on the 5 graph using dashed lines. 4 y = 3 3 x = 1 1 0 4 3 2 x 1 1 2 3 4 5 6 1 Sketch 2 3 Tip To check value For of the You x For to can then each a the graph Practice 1 where graph right in of is Example sketch the located, the you vertical 3: when curves x of the functions ● write down the equations ● write down through the domain the value of h and (x ) = of and the 2; these when x its the = 2, equation left. y = 4. points. asymptotes range. b f 1 (x ) = c x + 3 + 2 - 11 e f + π (x ) = x x E10 Change 1 f (x ) = + 8 x 1 1 (x ) = 2 2 6 = into to 1 - 7 x f y value k 1 d 0, a below: nd f = substitute and 2 ● a can axis, 5 a the function. A LG E B R A 2 For each function ● draw ● sketch ● state and label the the below: the asymptotes function domain on and a graph range. 1 a y 1 = - 4 b y c x 1 d y 1 = x y = 4 + 3 x 1 = e x y 1 = + 5 2 x + f y = 2 +1 x 3 1 3 Each of these functions has an equation of the form y + k. = x Find the equation a of each graph. b y y 2 x = 2 x 0 0 8 6 4 h x 2 2 4 6 = 2 0 8 8 6 4 2 2 x 2 4 6 4 4 y = −5 6 6 8 8 10 10 y c d y x y = = 8 2 = −7 y 6 10 4 8 2 6 −4 0 4 0 10 8 6 4 x 2 2 4 6 y = 2 2 2 x = 3 4 0 6 4 2 x 2 4 6 8 10 6 Problem solving 1 4 Find the equation of a curve y = + k x a y = 4 and c y = -1 x = 3 b y = 2 and the x = 2 d y 3 and = asymptotes: y-axis 4 and with h x = 3 4 1 5 Describe the individual transformations on f (x ) = for a each set i h > 0 ii h < 0 of values for h b and 1 to x obtain f (x ) = + k x h k. i k > 0 ii k < 0 E10.2 Meet the transformers 2 27 Example For each 4 function ● list ● nd ● hence the below: individual the equations sketch the transformations of the graph on asymptotes of the function. a b Use the values a, h and k from the a rational h = in 3 ⇒ the horizontal positive translation of 3 function . units x-direction y 10 a =10 k = 2 ⇒ ⇒ vertical vertical dilation scale translation of factor 2 10 units 5 in the positive y-direction y Horizontal asymptote: y = = 2 2 x 5 5 Vertical asymptote: x = Draw the asymptotes 10 3 as 5 dashed sketching x = lines the before graph. 3 b Rearrange factorizing ⇒ horizontal translation 1.5 units in the positive the equation out the to look coecient = -2 ⇒ vertical stretch of factor 2 and horizontal y = 3 ⇒ vertical translation 3 units 8 x in the positive = 1.5 y-direction 6 Horizontal asymptote: y = 3 4 y Vertical asymptote: x = = 3 2 1.5 0 6 4 2 4 E10 Change x 2 2 2 2 8 x in the denominator. negative value of a gives reection a k of by x-direction A a like 4 6 8 reection in the x-axis. A LG E B R A The order for performing 1 Horizontal 2 Reection 3 Vertical dilation 4 Vertical translation For a rational multiple translation in the x-axis (if a horizontal ● k determines the vertical ● a determines a the Practice 0) : the the is: (k) determines factor functions (a) h ❍ < function either on (h) ● ❍ transformations horizontal reection in the translation; translation; dilation x-axis (if of a the the vertical asymptote is x = h horizontal asymptote is y = k factor < or the vertical dilation of 0) 3 1 1 Perform these transformations on the rational function f (x ) = , then write x down the function obtained as a single algebraic fraction. 1 a Vertical dilation by scale factor , vertical translation of 1 unit in the 2 negative y-direction, horizontal translation of 4 units in the positive x-direction. b Horizontal vertical dilation translation by scale of 2 factor 3, horizontal translation of 3 units, units. 1 c Vertical dilation by scale factor , reection in the x-axis, vertical , reection in the y-axis, vertical translation of 4 translation of 8 units. 3 d Vertical dilation by scale factor 2 translation 2 For each of 4 rational units, horizontal function 2 units. below: 1 ● list ● nd ● hence the transformations applied to f (x ) = x the equations sketch the of the graph asymptotes of the rational 3 a f (x ) = - 5 x + b f f (x ) = 2x + 3 2 c f x (x ) = 3x 5 + 2 8 9 (x ) = - 6 5 d function. 5 e f 13 (x ) = - - 8 2x + 1 1 f f (x ) = - - 11 x E10.2 Meet the transformers 2 2 9 D The inverse ● Can ● Does a function science Exploration 1 Using your graph 2 Repeat step 1 solve rational own draw the line y for the graphs graph what a Find create them? = x. and Describe what the you line your results . inverse y = x. Reect the notice. of : c , the or of b Explain function inverse? problems the function 4 its in a 3 be a 5 GDC, of of tell Justify you why d about this function the inverse inverse of the relation relation is a of a rational function. function , algebraically. b Determine c Summarize Reect You could because y when x is the ● not = How the and say your that in This inverse are the and ndings discuss represents 0. domain the the means range about the inverse function function multiplicative that . of , . 8 reciprocal function of yx of y multiplicative = = 1. inverse However, , (or the y is the inverse reciprocal) reciprocal of x, of x, except function x inverse (reciprocals) and inverse functions dierent? ● What is meant ● What is the inverse function of ? ● What is the inverse function of ? Example Find the by ‘inverse function’? 5 inverse of . Interchange the Isolate 23 0 E10 Change x the and the variable y y A LG E B R A Practice 1 On 4 your GDC, graph each function 4 a y b y e -1 y y inverse of each of b y y y = +1 1 x x 1 + 6 x - 3 e y c = - - 8 x 1 f x 12 2x = x y 9 3x = 5 4 function: = 6 d + 1 f each + 1 grid. = 7 = x y x 3 the same 1 c = 3 + 5 a the 3 = Find on x x 2 inverse = - 3 y its 2 = x d and y = - + 3 x 4 Summary A rational expressed are a the real of For is of x, and numbers a reciprocal is x ≠ is the a f ( x ) can and rational Its zero excluding horizontal which be function domain and its is the range For a rational as x is h determines the horizontal ● k determines the vertical ● a determines set ❍ either the horizontal the vertical ❍ the horizontal ❍ whether the dilation translation dilation of that the is the vertical denominator function, line that f positive the ( x ) approaches 0. or never equal < 0) domain vertical the or graph not (a > is reected approaches (The the isy = For x = x-axis of the rational function . The range of the as the rational function is . denominator horizontal asymptote , h and the the asymptote is at x is = at y = k and the h vertical horizontal asymptote k Mixed 1 is the 0.) function asymptote in 0). asymptote vertical For or negative The can factor graph The reciprocal of a reection is a factor horizontal innity. For translation zero. line approaches : ● (a approaches function g ( x ) 0 function. function, the ≠ 0, excluding numbers asymptote function where g(x) , reciprocal real any quotient function called set as functions The of function practice each function below: 2 Perform these transformations on the 1 ● rational state the largest possible domain and f function (x ) = to obtain g ( x ). range x Write ● write down the equations of the down g ( x ) obtained as a single algebraic asymptotes fraction. ● sketch the graph. 1 a a y The b = - y = scale 2 is vertically dilated by factor 3, negative translated vertically 5 in y-direction and units horizontally 4 = - 8 x (x ) = x the y f +1 x x c function 1 5 2 d y = - + 2 x 5 units in the positive x-direction. + 3 E10.2 Meet the transformers 2 31 by 1 b The function f (x ) = is vertically dilated ● sketch ● nd the graph of the rational function by x 1 scale factor , translated 1 unit vertically in its inverse. the 2 1 y-direction and reected in the + 9 y-axis. x The f function (x ) = is reected in the vertically positive and + 1 by 2 units horizontally in by 3 the in m (x ) = - x + 6 8 + 2 1 n (x ) = the +1 3x 5 negative units 4 d 5 e y-direction - 3 x k (x ) = c x-axis, x translated h (x ) = b 2 10 1 c 3 g (x ) = - a positive p (x ) = f 4 x 4 x 5 x-direction. Problem solving 1 d The function f (x ) = is dilated horizontally x by scale factor translated 1 y-direction 12, unit and 4 reected vertically 4 units in in the the x-axis, in adult rational list the drug dosages pharmaceutical for drug the mg. dosage says that the children’s dose is x , where x + 12 x istheageofthechild. function: a ● 50 = 50 each calculates certain the For is a x-direction. C 3 For dose Young’s positive dosage children. negative horizontally Young’s individual transformations Calculate the dosage of the medicine for a applied 10-year-old child. 1 to f to (x ) = obtain the given a function b x Rewrite the function in the form C = + k x ● nd the equations of the asymptotes c Review 1 in Catherine and then She starts is to Explain the series Yen. travelling from New York to with Tip 1000 spends USD 40 and 000 converts Yen in this Tokyo, her remaining money into AUD reaches reciprocal Sydney. Using functions and your the knowledge below, Catherine explain now has how currency in much the rate, W is the work time (in this case ll 1 reservoir), t is taken. of conversion a rates is when the she r and required converts transformations. Tokyo Sydney. She of context where to h Let the the fast hours needed to ll one reservoir from money pipe be p. The rate of lling is the AUD. 1 reciprocal 1 USD =113.4 YEN = 1.32 Two in oil pipelines Nigeria. three times pipelines lled in One 14 between pipeline faster are run than a can Abuja ll second operational, an oil an and oil b tanker pipeline. reservoir If How you have be c As it both helped explored the 232 apply and our statement equivalence of in understanding E10 Change . Find the reciprocal inquiry? a rate of lling by the slow pipe. an takes the expression Give specic variety of of scientic forms has principles. for the two pipes together. 14 hours nd reservoir discuss change humans the pipelines, ll Statement of Inquiry: Representing for nd working both can Hence to and = Lagos hours. Reect r p function 2 function AUD examples. to p. ll the Hence with just reservoir nd the the slow with time pipe. taken Unmistaken E11.1 Global context: Objectives ● Using ● Solving Orientation Inquiry trigonometric expressions identities and identities solve equations to ● simplify F equations involving functions time How do you solve trigonometric How many solutions How do you does equation prove a have? trigonometric identities? ● How to ● D can solve Can you use trigonometric trigonometric two dierent identities equations? solutions both be correct? ● How do we dene ‘where’ and ‘when’? Creative -thinking Make unexpected or unusual connections between objects and/or ideas E7 1 Statement of Inquiry: Generalizing help and dene applying ‘where’ relationships and between measurements in space ‘when’. E9 2 E11 1 23 3 S P I H S N O I TA L E R ● can and questions trigonometric C ATL space equations? ● trigonometric in Y ou ● should conver t radians already angles and from vice know degrees how to 1 to: Conver t: versa a 120 b to 135 radians to radians π c to degrees 6 5π d to degrees 3 ● nd or the value tangent of of the any sine, angle, cosine 2 Find a special the a missing sine, angle cosine or when given tangent 3 trigonometric Find x ● use quadratic the side or sine functions 4 sin A in sin B = = Describe 0.5 the graph of of transformations f ( x ) = g( x ) = to a nd a sin x to on give the 3 sin ( 2 x ) + 5 2 equations rule angle when: sin x graph solve ) cos x = 0.321 the ● 3 value b transform ( tan 47 a ● of : 2π cos c nd value sin 45 angles b ● the including missing 5 Solve 15 + 7 x 6 a Find ∠ B in - 2 x this triangle. = 0 triangle. B sin C = a b c 6 cm 60° 3 b Find the cm length of side x, to 3 x 30° 40° 8 Trigonometric F In ● How do ● How many problems with you solve trigonometric solutions right-angled equations does a triangles, equations? trigonometric you solve equation trigonometric 1 to get a single solution, such as solving sin x = Exploration equation can 234 1 you will investigate have. E11 Equivalence how many equations π to get x = 30 2 In have? or radians. 3 solutions a trigonometric s.f. G E O M E T R Y Exploration Draw the graph 2 Draw the line 3 Use of graph State 5 Generalize how to many 8 how domain how many numbers. this ● In the angles Explain equation 1 and you to 8 if the the for . angle that satises the important it to trigonometric domain, Trigonometric identity is there which this equation you the domain other angle . within when the domain is the set know. , is state the how set of to nd real of , all angles that numbers. for . 1 number using generalization state within b equation graph same Why An each this domain discuss nd of if the for Explain. given of equation , how ndings: negative? is value this value satisfy domain solving a your steps your the satisfy the in ● angles within Would , graph. if sine b Repeat ● a domain Reect In many Generalize 9 ndings: has the satisfy same satisfy within real function determine a State of the angles your also 7 sine . 4 State the on equation 6 T R I G O N O M E T R Y 1 1 your A N D in of the solutions unit Exploration specify a to sin x = and cos x = circle? 1, domain does for it the matter if values of b is positive or when equations? may be multiple solutions to a trigonometric equation. identities: true for all values of the variable. E11.1 Unmistaken identities 23 5 Example Solve these graphically 1 equations using a algebraically GDC or for dynamic a Verify geometry your solutions software. b Rearrange to isolate sin θ. The domain is a given in radians, so give angles Find in one radians. value of . 1.1 π y 2π 3 2 3 1 2 y = 2 0.5 Graph the LHS and the RHS of the x 0 π π 3π 2 2π equation 2 0.5 y = sin where and they nd the x-coordinates intersect. x 1 b Solve each equation separately. ⇒ Use the identity . ⇒ Answer Use is the outside the given domain. identity . 1.1 Use the same identity again, as long y 4 as the solution is within the given 3 domain. 2 1 (0.322, 0) (5.96, 0) Set 0 (2.82, 0) (3.46, 0) 1 2 y = 9tan2x − 1 3 4 23 6 E11 Equivalence x your window to the given domain. G E O M E T R Y Practice 1 Solve ifnot A N D T R I G O N O M E T R Y 1 each equation possible, for round 0 to ≤ θ the ≤ 360°. nearest Give exact degree. answers Check your where possible; answers graphically. 1 a sin θ = b 4 cos θ e tan θ = -1 c tan θ f 2 cos θ = 1 2 3 2 sin θ d = -1 = - = - 3 4 2 Solve ifnot each equation possible, for round 0 to ≤ θ 0.01. a 2 cos θ = -1 b d 6 cos θ = -5 e ≤ 2π . Give Check exact your 2 cos θ = answers answers where possible; graphically. 2 c 2 sin θ f - = - 3 5 7 cos θ = 1 sin θ = 1 3 2 g tan θ = -1 h 3 tan θ = 3 θ sin i = 1 parts the j to q, factorize quadratic rst. 1 2 2 θ sin j + 2 sin θ + 1 = 0 k 2 θ 4 cos - 1 = 0 tan l θ = 4 2 2 m 2 cos p 2 tan θ + cos θ = 1 n 6 cos q 2 sin 2 a b - cos θ - 1 = 0 o 2 sin θ cos θ + sin θ = 0 2 θ - tan θ Problem 3 θ - 6 = 0 θ 2 ) sin θ + (2 - - 2 = 0 solving Find the set of values in the domain 0≤ θ ≤ 2π such Find the set of values in the domain 0≤ θ ≤ 2π that that sin satisfy = the cos equation: 2 sin 4 x + sin x cos x a Show that b Hence Find all a a 0. 6 sin x cos x solve Example = 6 sin x + 3 cos x cos x + 4 sin x + 3 cos x + 2 + 4 sin x ≡ + 2 (2 sin x = 0 in + the 1)(3 cos x domain + 2). 0≤ x ≤ 2π 2 solutions , within the given domain. b , Let Substitute ⇒ a variable then the for 2x. domain If of the u = domain 2x of x is is . ⇒ Solve for u. or Substitute 2x for u and solve for ⇒ ⇒ Continued on next page E11.1 Unmistaken identities 237 x. b If the domain of x is Let the domain of u = then is . ⇒ ⇒ or Reject since it lies outside ⇒ Practice 1 Solve 2 the equations within the given domain. Check a sin (2θ) = 1, 0 ≤ θ ≤ π θ your = − 2 solutions graphically. 1 cos b , 0 ≤ θ ≤ 2π 2 3 sin θ = c 3 , sin 0 ≤ θ ≤ π d cos (3θ ) = 1, ≤ θ 0 ≤ 2π 2 e 3 (5θ) − g 2 sin (3 x ) i sin = = 1, 0 ≤ θ x ≤ π 0 , 0 ≤ ≤ π f cos h sin (2x) j 3 cos 2π 2 2 (3θ ) − sin (3θ ) = 0, 0 ≤ θ ≤ = 1, 0 sin θ 2 θ ≤ θ ≤ (2x), = 0, 2π 0 ≤ x 0 ≤ θ ≤ 2π + cos 3 (2θ ) 2 ≤ π π 2 k 2 sin (3 x ) − 3 sin (3 x ) = −1,0 ≤ x ≤ 3 2 3 co l (2x) − 5 cos (2x), 0 ≤ x ≤ 2π C ● How do ● How can you prove you use trigonometric trigonometric identities? identities to solve trigonometric equations? Exploration Identity 1 For the 2 1 this right-angled trigonometric triangle, write down ratios: r y a tan θ b sin θ = = θ c cos θ x = Continued 23 8 E11 Equivalence on next page the domain . G E O M E T R Y 2 Rearrange your Explain Identity 4 For sin θ of how equation for cos θ and cos θ equation terms 3 your this to relates sin θ for make x to how r 1, to make the you y the subject. subject. Hence calculate tan θ A N D T R I G O N O M E T R Y Rearrange write using tan θ the in unit circle. 2 the unit expressions a circle where = write for: b c P(x, y) 5 Using the right-angled triangle, write an r y expression for r in terms of x and y. θ x 6 Rewrite using 7 Test your your that values obtuse expression result your of . result Make angles Reect from and and is sure for step 4 true for you negative discuss dierent test some angles. 2 ● Why do you think Identity 1 is called the Ratio ● Why do you think Identity 2 is called the Pythagorean Ratio identity? identity? identity: Pythagorean Rearranging identity: the Pythagorean identity gives two equivalent identities: and Once you have trigonometric Example Solve proven an identity, you can use it to simplify and solve equations. 3 for , and check graphically. Use the Pythagorean identity to write the Multiply by Factorize Continued equation on 1 to and next in sin θ avoid solve negative the coecients. quadratic equation. page E11.1 Unmistaken identities 23 9 or or ⇒ or Find the all the values of in the given domain. ⇒ Reject as it is outside the domain. ⇒ 1.1 y 1 2 y = 2 cos x − sin x − 1 (2.62, 0) (0.524, 0) 0 x 1 2 Practice 1 Solve 3 these exact form trigonometric (in radians) if equations possible, for 0 ≤ θ otherwise ≤ 2π . write Leave your your answer answer to 3 in In s.f. Japan, use 2 a 2 θ cos = 1 b 2 θ sin - cos θ = 1 aid 2 2 θ c cos e 3 cos cos θ + = 2 θ sin d 2 θ 3 tan cos = 2 + cos for θ to 3 - 6 cos θ these s.f. below remembering sides involved 2 θ = θ sin - 3 in Solve shown 2 θ the 2 2 students memory 2 θ - sin the trigonometric where equations for 0 ≤ θ ≤ 360° . c 4 sin θ answer + 1 = cosine 0 b 2 cos d 4 sin θ sin θ = 1 - cos θ = 1 + the The triangle for and letter superimposed 2 θ - cos sine, formulas tangent. 2 θ 2 sin your appropriate. 2 a Write the is on drawn 2 = tan θ 2 e 4 tan 2 θ cos 2 θ - sin θ to sides 2 θ = cos include Determine = is an identity. Justify your answer. 2 can use in case. 1 whether 1 + tan θ You two solving 1 3 involved θ each Problem the the other identities. same as trigonometric To prove an sin in θ identities identity, you work have on previously one side until proved your to prove result is the os the other side. an 24 0 E11 Equivalence G E O M E T R Y Example Prove A N D T R I G O N O M E T R Y 4 that . LHS: Start side on one that side. seems Tip: more Start on the complex. = Use = = Write the expression with common the Ratio identity. denominator cos θ = Use the Pythagorean identity. =RHS Example Prove 5 that . LHS: Factorize Use = the the Pythagorean quadratic identity, expression then = factorize in the the Cancel numerator. denominator. common factors. = = RHS Objective iii. prove, To prove be if true. the you graphs Prove Investigating verify other If Practice 1 B: or and identities, are are unsure the patter ns justify , make about same, the general sure a that r ules you statement, statement is only you use can probably results justify an that it by have been graphing proven both to sides: identity. 4 these identities: 2 1 sin θ cos θ tan θ ≡ cos θ a b cos θ 2 c cos ≡ 1 sin θ 2 θ (tan + 1) ≡ 1 d sin 1 2 θ θ ≡ 1 1 + 2 tan θ E11.1 Unmistaken identities 241 1 4 e 2 θ sin + cos 2 θ 2 sin ≡ 2 sin 2 θ sin f + tan 2 θ θ + cos ≡ 2 θ cos In part g, multiply 1 + sin θ 1 the tan θ cos θ ≡ 1 + h cos θ RHS by . 2 cos θ g 2 sin θ + sin θ ≡ 1 1 + sin θ 2 cos θ tan θ cos θ Problem Tip solving When 2 Use your GDC or graphing software to graph these both identity Based on the graph, conjecture an identity and justify your 1 a + (1 tan x sin x ) sin x + tan x in are part work - cos x - 1 on sides reach equivalent ATL 3 ● Explain how verifying an identity is similar ● Explain how verifying an identity is dierent The D ambiguous ● Can ● How two do Exploration 1 Find 2 In two the dierent we dene to solving to an solving equation. an equation. case solutions ‘where’ both and be correct? ‘when’? 3 angles diagram where below, sin nd B = , angle 0 B < to B 3 ≤ 180 s.f. B 10 30° C A 10√3 3 Hence, 4 Based step 5 Can 2. nd on your Write you angle the B ? third answer down construct If so, angle to the a write of step other triangle down the 1, triangle there possible with the (angle should A angle and of C ). have solution angle third for angle this the been two solutions E11 Equivalence in B second value for triangle. Continued 24 2 you can independently both you discuss complex, h, (cos x ) and an b cos x Reect of answer. as sides expressions. on next page until an expression. G E O M E T R Y 6 Based (give on an the diagram exact below, nd the value of angle N in this A N D T R I G O N O M E T R Y diagram value). N n = 5√2 45° M P 7 Using the formed 8 Write When are other down using two i word word each why for why the sine of sine Latin the there is SSA is word jiba, for is of for missing called will the and it is of N. Can answers? a triangle be Explain. triangle. angle in a give triangle, you ambiguous cosine (S) you or ambiguous to one case sometimes solution for case of an error in sinus, misread hence as the a or a the there as sine ; the rule. any given of three combination whether missing or not you side/angle. these: SAS case. translating mathematician was for ambiguous normally (A) state nd iii the are angles scenarios, rule ASA Arab value these this triangles, sides following or result fold possible each 4 produces the 5√2 calculator with no = angles a either rule famous is nd problems the ‘sine’ by triangle and For and Your This ii Example In . SSS written to information: use Explain The rule discuss solving other possible 180 of Explain the is and both. only the angle solutions. pieces would nd given sine When of ● the the solution rule, the possible Reect ● sine with m a trigonometry Al-Khwarizmi. jaib, word which In means book Arabic ‘fold’. the And sine. 6 ABC, ∠B = 40 , BC = 14 cm and AC = 10 cm. Find the other sides angles. B 40° 14 cm Sketch the triangle. C 10 cm A Continued on next page E11.1 Unmistaken identities 24 3 Find both possible values of ∠ A of ∠ A or If ∠A = 64.1 ⇒ If ∠A = c Reect How Does In = 15.7 cm c = then 6.36 the = ∠C = Find 24.1 ∠ C ∠ C and and side side length length c c for for the the rst second possible possible value value of ∠ A cm lengths also Find 75.9 discuss opposite this triangle , and Example and ∠C are angles ● then 115.9 ⇒ ● , of them? hold 5 the sides Why true for in does a triangle this triangles make related to the sizes of the sense? produced by the ambiguous case? 7 XYZ, ∠ X = 65 x = 23 cm and y = 18 cm. Find the other sides angles. X 65° 18 cm Sketch Z the triangle. Y 23 cm Find both possible values of ∠ Y or If ∠ Y = 45.2 , then ∠ Z = Find 69.8 ∠ Z values and of constructed z If = ∠ Y 23.8 = cm 134.8 Therefore, 24 4 the , then only ∠X + ∠Z solution is is already the one E11 Equivalence more already than 180 found. . length ∠ Y. Verify with of side that each a of z for the triangle these two can be possibilities. G E O M E T R Y Reect Although and it ambiguous there are In sucient case, two Practice 1 is for 6 this you course nd a without to check general rule checking both to them solutions determine of or not both? ABC, nd to 3 all possible values for the measure of angle = 38 , a = 14, c = 22 b A = 71 , a = 10, c = 7 c A = 62 , a = 12, c = 3 d A = 53 , a = 11, c = 13 missing 0.1. a r = 5 c r = 20 In triangle sides Make cm, = 8 q = 30 ABC, and sure q m, C s.f. A the the whether a Find T R I G O N O M E T R Y 5 triangle nearest 3 could solutions, Giveanswers 2 discuss A N D all nd = ∠R m, nd you ∠R cm, angles = in all triangle possible 30 22 possible values PQR. all values to the solutions. b r = 26 d r = 7 for Give cm, km, angle B q q to = = 22 13 the cm, km, ∠R ∠R nearest = 55 = 18 0.1. C 15 7 26° 4 In to 5 In ∆ DEF, the ∆ RST, tothe 6 e = r = Determine f = 6 m, and 25 m, s = 30 m, and how many unique with ∠ P = 50 , p = 10 b ∆ PQR with ∠ P = 90 , p = 3 c ∆ PQR with ∠ P = 115 , d ∆ PQR with ∠ P = 62 p the at at point a Sketch b Determine A all with m and the B. is Find all possible solutions for ∠F ∠R = 40 . Find all possible values of t , p = = are possible m, q = 6 m cm, q = 2 cm 9 m, 2.8 q km, = 3 m q = 3.0 for each scenario. km the 10.8 Seen a Determine b Calculate 10 km from from the diagrams a ship, ship the at point angle C and between 8 the km from a lighthouse for this distances situation. from the ship to the sailboat, to the kilometer. land long, is enclosed respectively. by a The fence. other Two side sides forms of an the fence angle of are 41 side. how all a of m m is possible of plot 7.6 A 48 possible tenth triangular 10.8 point sailboat nearest . solving lighthouse and = 19 triangles ∆ PQR A ∠E meter. a sailboat 8 m, 0.1. nearest Problem 7 7 nearest many possible lengths lengths are to possible the for nearest the 0.1 third side. m. E11.1 Unmistaken identities 24 5 Summary An identity is true for all values of the variable. Rearranging equivalent Trigonometric the Pythagorean identity gives two identities: identities: and When in a using solutions. Ratio identity: solution the Pythagorean Mixed the triangle, Your as sine rule sometimes ; calculator the ambiguous to other case is for nd there a are will give 180 the missing two . sine angle possible you one This is called rule. identity: practice 2 1 Solve each equation for 0 ≤ θ ≤ 360 . Give exact 4 a θ Find sin θ if = , for 0 ≤ θ ≤ 360 2 answers where possible; if not possible, round to b 2 d.p. Check a cos θ c 5 tan θ = your answers 0 3 tan θ b = -2 cos θ > 0, Problem -1 2 = If in which quadrants θ ? is graphically. sin θ d c solving tan θ Find if cos θ < 0. = 7 1 5 Find tan θ if os θ = - and sin θ > 0 . 1 e 3 cos θ = 2 sin θ f 2 = 2 2 Without using a calculator, nd these angles 2 6 Prove the identity: sin x cos x tan x 7 Prove the identity: sin x - sin x 8 Prove the identity: ≡ 1 - cos in 2 radians, for 0 ≤ θ ≤ 2π . Give exact 3 a sin θ 2 = b cos θ 1 - cos θ + = e cos θ = 3 d sin θ = f tan θ = sin θ sin θ + cos θ sin θ 9 3 Prove equation answers for 0 ≤ θ ≤ 2π . a in radians when c 2 sin give = θ cos Solve ≤ θ these answers in trigonometric ≤ 360° . Write your degrees to appropriate. the 2 - (2θ) 3 = b 1 d 5 cos θ 2 cos = 2 θ a sin b 2 sin c 2 sin d 3 sin 3 (3θ) + sin θ = cos θ 2 = −1 θ = cos θ 2 + 2 2 θ + 3 cos θ = 3 2 24 6 2 θ sin E11 Equivalence equations answer possible, 0.1 2 sin θ 1 ≡ 2 4 θ sin for Give where nearest 1 + identity: sin 0 otherwise the 3 10 exact - 1 2 2 each x cos θ 1 Solve sin ≡ cos θ -1 1 3 ≡ 2 1 - sin θ tan θ 3 x = - 2 c cos answers. θ - 4 cos θ - 4 = 0 to 3 s.f. θ x G E O M E T R Y 11 Solve 0 ≤ θ these 2π ≤ radians if . trigonometric Leave your possible, equations answer otherwise in for exact accurate 13 form to 3 in s.f. Find and both solutions sketch accurate each to 1 A N D for T R I G O N O M E T R Y ∠ B solution. for each Write triangle, your answer d.p. 2 a 2 cos = 3 cos a B 1 = 2 sin θ b 5 cm sin θ 2 tan θ c θ sin 2 tan θ = 30° 2 d 2 cos e 3 cos f ( 6 θ + 3 sin θ = cm 3 B b 2 θ - 5 sin θ - 4 = 0 2 2 - 2 ) cos θ - 2 θ 2 sin = 1 - 2 4 2 cm 44° Problem solving 5 cm 1 2 12 Determine whether is θ - 1 = tan an 2 θ cos identity. Justify Review 1 Anouk a in and standing 20 m a 40 away are looking and answer. context Timur shoreline, measures your angle the standing at an between island. from 30 island m out where Kelly is on apart to Anouk Timur the N along sea. is island, B O Timur. 35° a Find the nearest two 0.1 ) possible that angles Kelly (to could the measure 250 400 b between Timur Find two the nearest 0.1 between 2 A canoe buoy it 5 and the the the Anouk course dock, canoe’s of and the whether and possible answer. travels travels angle not A toward the You will than once. from 3 the 3 while Lucas He from a is is lost knows his path, but walking A. the current walking point that after at east. a from point B but 400 the is dock, more and than the orienteering line the O. meters bearing In the an position, Lucas’s away on nish of is he 125 nish nish says line. line due He diagram, GPS use the sine rule more km. a Find how b Explain away one far east Lucas is from point O is Lucas isn’t nish A, how far but line could not Lucas be is be 250m located from the at follows is he of now only at 250 walks m to there. E11.1 Unmistaken identities B actual line. course. realizes he the point east instead he how from Determine nish solving to buoy c Problem have Determine 12 there a buoy, another between is canoe or the measure reaching position explain (to could Kelly. dock Upon the angles Timur and the away. distance Anouk. possible that leaves km changes From ) and 24 7 4 Both sun Earth (S) in distance 149 (E) paths from million from and Venus that are Earth to Venus to the sun orbit nearly the kilometers, (V) is circular. sun while around is the a The roughly distance 108 a system, approximately the Sketch diagram showing (Draw the form triangle.) a of the planets this part orbits and the of of the the sun so solar two that planets. they million b An astronomer measures the angle SEV to be kilometers. 20 Determine Earth Reect and How you have at space At can explored the put laws of turn the the his physics statement of resulting in of the a inquiry? the that forces Earth due at odds later, and the there on gravity for with the the of a theory, relativity. no dierence person and law unied special was Einstein relativity Einstein theory acting to Albert of between ‘when’. framework was general between the new theory gravity realized and century, years Einstein on 20th but relationships ‘where’ special Some concepts applying dene provided of gravity. the of forward which and help a standing person −2 travelling This is a in a rocket simplied accelerating description Equivalence Principle studying eect It is a common gravity’ aboard for the for the The free as mistake 90% are in force of toremain 24 8 fall. the by fall. term ‘zero Astronauts Station fall, them is is E11 Equivalence the as surface. because which motion. (ISS), but balanced ISS ms inspired Earth’s is 9.81 Einstein’s free free upon the at the Space earth of orbital in experienced the velocity in on of was use free acting that towards tangential to constant weightlessness fall objects describing gravitational high of which International example, point. discuss Give specic examples. Statement of Inquiry: Generalizing that by the the allows it measurements in how far Venus could be from Go E12.1 ahead Global context: Objectives ● Developing ● Using and Orientation Inquiry the laws of log logarithms in in space and time questions ● What ● How can ● How do ● Is are the laws of logarithms? F the laws expressions of and logarithms solve to simplify equations you prove generalizations? C Proving the laws ● Proving the change of logarithms of base you solve logarithmic equations? formula D ATL change measurable and predictable? Critical-thinking Draw reasonable Statement of conclusions and generalizations Inquiry: E6 1 Generalizing that can changes model in duration, quantity helps frequency establish and relationships variability. E10 1 E12 1 24 9 S P I H S N O I TA L E R ● Y ou ● should evaluate already logarithms know using how a 1 calculator to: Evaluate: a log 5 b In 3 c log 6 2 x ● solve equations involving 2 Solve the equation 3 3 Solve the equation log = 20. exponents ● solve equations involving logs ● conrm algebraically 1 and 4 = 7 7 Show algebraically and graphically x graphically that two functions are x that f ( x ) = 3x 4 and + 4 g( x ) = are 3 inverses ● nd the of each other inverse of a inverses logarithmic 5 Find function y = of the each inverse 2 log (x + 3) other. of the function 11. 5 Creating F ● ATL What are Exploration 1 Choose any evaluate log 2 laws of logarithms? value of a 1 logarithm log a in log 3 8 + log a 10 + log 81 product and use decimal your calculator to places. 1000 9 log a the 3 a log a Examine base, to 32 log 100 a + the table a a log for 6 log 4 a log this a a log The the positive each + generalizations a patterns rule: and log xy write down a generalized rule: = a 2 Do the log 3 same - log a log 8 - log 100 - - Examine 10 log log 10 a log a quotient table. a log the this 2 log 4 a 81 in a a a The expressions log 2 a log the a a log for patterns rule: 243 a and log write down a generalized rule: = a Continued 25 0 E12 Generalization on next page N U M B E R 3 Compare the values in each column to discover a pattern. Scottish mathematician and astronomer John Examine the patterns and write down a generalized Napier rule: (1550 – 1617), n The power rule: log (x ) = most a 4 Evaluate log 1 for dierent values of famous for discovering a a logarithms, Write down a generalized credited The zero Evaluate log a for dierent values of The 6 down unitary generalized Write = solve this Reect for as a and How are Give two ● Explain ● How fractions. rule: rule: Rewrite Hence ● for a the notation a a Write also for introducing rule: decimal 5 is rule: the y y as in logarithmic terms of generalized discuss rules specic why a the you statement. x rule. 1 discovered similar to the laws of exponents? examples. zero rule and the unitary rule are true. lnx Laws of can you simplify e ? logarithms + For all logarithm The product The quotient The power The zero The unitary rules: x, y, a ∈ rule: rule: rule: rule: rule: E12.1 Go ahead and log in 2 51 Example Rewrite 6 1 ln x - 3 ln 3 + 2 ln x as a single logarithm. The power rule: = The product rule: log xy = log a The Example Express in = ln 1 = ln 1 = 0 quotient terms of x and y, where x = ln a and y = The ln (ab) The The ln (ab) = Rewrite (x + zero log 4 + c 2 log 5 + y) expression as a single logarithm: log 3 b log 5 – d 3 log x log 2 + log 6 1 + 3 log 2 + log 1 - log y + log z 2 e 2 5 ln x Express 3 ln 2 in + terms 4 ln x of ln f a and ln log y + 4 log x (5 log 2y ln ab b a e c ln ( a f ln ( a b) b 1 ln log 3x) 2 ln d + b: a a ln b ) 2 g 3 a h b Problem 3 Write each a 3 ln a a ln i 2 b ln b solving expression in terms of x and y, where log 3 = x and log a a log 18 b a d log g log log 2 9 e log a c 162 a 25 2 E12 Generalization log 0.5 a 36 6 a a a power rule: rule. rule. . ln b) 1 each a y a rule: quotient The 1 log ln b. ln (ln a Practice + 2 ln ln x a f log a 27 = y. product rule. N U M B E R 4 Express in terms of x and y, where and x = log a 5 2 a log (100a ) b y = log b a 3 b and log 4 3 c log 6 1000 a 8 d Find the the 10 a b 3 inverse algebraically of log Example 1 b 100b of the function using the laws function and its of g ( x ) = ln x logarithms. ln (x State the 3) and conrm domain and it range inverse. Use the quotient Interchange Solve for y, and x rule. and simplify. x = ln e = x = g 1 Since g ( g 1 ( x )) Domain of g Domain of g is = x x > 3; ( g ( x )), range of g they is 1 y are > inverses. 0. 1 is x > 0; range of g is y > 3. E12.1 Go ahead and log in y. 253 Exploration 1 Describe the 2 transformations on the graph of f ( x ) = log x that give the x that give the 3 graph of g ( x ) = log (9x). 3 2 Describe the transformations on the graph of f ( x ) = log 3 graph of h ( x ) = 2 + log x 3 3 Graph down 4 a the functions what you Describe the the graph f, g notice. and h on Explain, horizontal the same using dilations coordinate laws that of axes, and write logarithms. transform the graph of f into of: i y ii = log (27x) 3 b By using that the laws transform of the logarithms, graph of f describe into the i the horizontal graph of : ii log y = translations (27x) 3 5 Summarize what transformations Practice 1 Find the its inverse and c f learned and in this Exploration translations with about the logarithmic functions. of each function algebraically. and State prove the that domain it is and an inverse, range of both the function inverse. x a have dilations 2 graphically and you of (x ) h( x ) = = 3 2 4 log (1 + 2 x ) b g (x ) = d j (x ) = ln ( 2 x ) ln ( x + 2) - ln ( x - 1) n 2 Use the vertical laws of logarithms dilation of 3 Given f (x ) = the 9 to graph explain of f ( x ) = why the log x graph for any of g ( x ) positive = log x is a n. , log use properties of logs to nd an equivalent function. 3 Describe the x transformations on the graph of y = log x that give the graph 3 of the equivalent Problem 4 a Use solving properties i g (x ) = function. of 8 logs to nd an equivalent expression ii h( x ) = log 2 b Then describe x function: (x + 3) 2 the each 2 log for sequence of transformations on the graph of y = log x 2 that give 25 4 the graphs of g and h E12 Generalization N U M B E R Proving C ● How can the you generalizations prove generalizations? c If a and b are equivalent to positive log b = real c. numbers, Does this then mean the that exponential the exponent statement rules are a = also b is related a to ATL the logarithm rules? Exploration 1 Proving Let log the x = 3 product p rule and . a a Write both b Multiply c Write d Substitute these the expressions two expressions as exponential together to statements. obtain an expression for xy. Internet this expression in logarithmic engines and every . to You should have the product Proving the quotient rank website determine rule. an 2 search form. approximate measure rule of important Let log x = p and is. Write both these expressions as exponential Divide c Write to obtain an expression d expression Substitute in logarithmic and form. should have the a 5 Proving the power is 100 with site quotient rule. The 5 3 this 2 Raise 3 Write 4 Substitute You should Reect ● this How = 2 expression expression of on as an exponential to in the power order statement. n. logarithmic an the scale, magnitude power of is a 10. form. . have the power discuss you use a rule. 2 graphing tool with a slider to demonstrate the 2 power ● What rule for f ( x ) = log (x transformation takes )? the graph of f ( x ) = log x to the graph of 2 f ( x ) = log (x )? of of signies logarithmic expression and could than rank rule of this a dierence orders where Write rank . . 1 a times a magnitude Let a scale, with popular two 3 site more 3. You is for of this Ranking logarithmic statements. so b site . a a how the Explain. E12.1 Go ahead and log in 25 5 Example 4 Express as a single logarithm. The The power rule. product rule. Expand. Practice 1 Express 3 as a 4 log c 3 ln ( x a single logarithm: p + 2 log q b n log p d ln x f 4 ln x 3 log q 1 - 2) - ln x - 2 ln ( x - 2) 2 e 2 1 Let ln x a = ln x, x a b = ln (x 1) and c = ln 3. Express x 1 ln (3 x terms - 1) of a, b and c : ln (x x ) x 2 c ( x 2 b ln in + 2 ln ) d + 1 ln x 2 e ln 3x + 6x Problem 3 Express as + 3 solving a sum and/or dierence linear logarithms: 2 2 a of ln ( x b 9) ln ( x + 5x + 6) c d + 1 can 2 x 4 use a 2 x - 5x - 6 ln e You x ln f x 3 x + calculator to nd x 4 the of 4 x 3 - 3x 5x logarithms 4 2 - 10 x 20 ln 2 ln any number with any base. You Until quite recently, calculators could not do this. Books of log tables the logarithms to base 10, and mathematicians used the change of base may formula change Any are logs positive the (base most 10) simplifying large 25 6 other value useful and Logarithms very to the date bases. can for be ‘natural’ back to astronomical numbers the base practical of logarithm 1614, a logarithm, applications when e). John Napier E12 Generalization which but the (base calculations together. are often the two bases ‘common’ took an interest involved that logarithm in multiplying of used base to formula calculate have gave in E6.1. N U M B E R ATL Exploration 4 How log to calculate 5 using logs to base 10 2 To nd when Let you , 1 Write all 2 Equate 3 Substitute 4 Equate , three the know for a in expressions to get : and expressions two and an exponential for b to identity get an form. identity involving z c x involving and a c x and y. y. In the exponents to nd an identity linking x y and z. step 3, use exponential the form of statement 5 Rearrange 6 Substitute the 7 to the change Use values Change of make of the base . subject. logarithmic from base x expressions for x y and z. You should have formula. the log table below to nd the value of . formula: x log x 10 Practice 1 Use a the log log table to nd each value 7 log b to 2 0.301029996 3 0.477121255 4 0.602059991 s.f. 5 0.698970004 6 0.77815125 7 0.84509804 8 0.903089987 9 0.954242509 8 5 10 log 3 log d log 3 e 0 4 2 c 1 5 9 2 f log 2 5 4 10 Verify your Example Given that a express b express results with a 1 calculator. 5 ln a = 4: as a simple as natural a single logarithm logarithm. a The power Change ln a Continued E12.1 on Go next = 4 of is rule. base. given. page ahead and log in 2 57 b = Practice 1 Given 5 that ln a = 5, express as a simple natural logarithm: 3 a log (x 2 ) b log a (x 1 x c log x d Given a that ln a = 1, express as a single log a 2 2 ) a 3 logarithm: 3 a ln ( x ) + 2 log x b 2 ln x 3 log a 1 c 3 log x + log a x d A ● How ● Is do 3 2 log of Example both x equations you change technique logarithms 3 a Solving useful x 2 ln a 2 D x a for solve logarithmic measurable solving and equations? predictable? equations involving exponents is to take sides. 6 Solve by taking logarithms of both sides. The power rule. Isolate x = 2.32 (3 s.f.) Reect and Show you the that original prefer? Use discuss can obtain equation as a 3 the same result logarithmic Explain. 25 8 E12 Generalization in Example statement. 6 Which by rst rewriting method do you a calculator to x evaluate. N U M B E R Example A 7 mathematician who have been very dicult 25% of has , Find the the determined exposed to to a where appoint population maximum is an has that news the city unbiased read number of the story the number after t population. jury to of days people is A given P by lawyer determine guilt in a the knows in a city function that crime it is after news. days available to select a jury. 25% of the population Take There is a maximum of 9 days available to select a natural implies logs solve equations that contain logarithms, you often need to use the laws a the x log 8 value + log 2 b log of 3 x = log each log + 1) x + + log log the argument the answer. and equation. 9 (x 3 = 2) log 2 log = 1 9 2 (3x) = log 2 9 The (x + product rule. 2 3x = 9 x = 3 The log has base, 4 2 b the 2 4 a in 2 (x logarithm parts: rst. Example Find sides. of three logarithms both jury. Each To of 1) + log 4 (x 2) = 1 2)] = 1 2 = 4 6 = 0 2) = 0 x = 3 arguments of the logarithms must be equal to each other. 4 [(x log + 1)(x The product rule. 4 2 x 1 x – 2 x (x x ≠ -2 since x 3)(x the + logarithm or log 4 Therefore, x = 2 ( 2 2) = log ( 4) doesn’t exist. 4 3 E12.1 Go ahead and log in 25 9 Practice 1 Solve 6 these equations by taking logs x 2 = 25 x b 7 b 4 b 7 × 4 5x = 41 c 12 = 5x 2 x 3 = Solve 45 these equations for = 25 Solve 9 2 x = 9 these exponential + 1 c 3 = c 5 × 3 60 x : 2 x 3 × 4 a 4 sides: Solve: a 3 both x 3 a of + 1 3x = 89 1 = 52 equations: Look 2x a 5 x 2 7 Find a the log x × + value + log 6 of log 5 b 2 x 2 (3x) 10 log + log + 1) – 1) x A = + 1 A: use state day log log t 12 log (2x + + 4) = -2 (x + 6) = 3 (x 5) 1) and understanding correctly rules you have in a variety found to of solve contexts these context problems involving equations. surveys school children years the to trac. At the end of 2010, there were 25 000 cars per school. number of cars C was modelled by the exponential 0.07 t equation C a that Show = children b By 7 The to taking taking time 25 000 × e by the end of 2015, there were 35 477 cars per day taking school. logs of children taken both to for sides, school an calculate reaches online video the time until the number of cars 50 000. to go viral can be modelled by an 0.5 t exponential watched a Describe b By By is is logs rewriting the Determine 2 6 0 the of the H = 15e number the watched calculate d t what taking video c function, and value both , of 15 500 000 which of H is since represents calculate the the in this the number rst of people times the video shared the video. is model. number of hours before the times. exponential number where hours sides, statement hours method (b before or c) E12 Generalization quadratic equations. equation: (x Knowing the taking After 0 7 log problems exponential 6 = 20 Objective can + 24 2 log You = for x = 10 × 4 3 (x solve log 12 20 iii. each 4 5 2 e in = 3 d b 7 (x log x 0 5 7 c = is as the a logarithmic video most is statement, watched ecient. 1 000 000 times. N U M B E R Problem solving Rearrange 8 to get all Solve: the 5x 2 2 x x 2 a = 5 1 x 3 b = x + 1 9 x 2 x If log x = p, show that rewriting it as a + 2 3 d = 2 x = terms side, 4 to c x − then isolate on one factorize x 2 9 logarithmic statement and solving a the resulting equation proves the power rule for logarithms. Summary Laws of logarithms The zero rule: The unitary + For all logarithm The product The quotient The power rules: x, y, a ∈ rule: Change Mixed 1 of base formula: rule: rule: practice Rewrite in terms of log a, log b and log c : a rule: log (abc) b c log ( a e log 2 b 4 c ) Express in and log b . y = terms d log b (a b a log (a given that x = log b) b log (10 c log (0.01a d log 4 ) 2 3 ab ) 4 b 2 ) c Express as a 2 log 5 + b 3 ln 5 − c 3 log a single log 4 − logarithm: ln 4 + Find the ln 8 5 b 5 + log 4 the inverse its 1 inverse. 2 log 4 − 1 each function of Prove 2 x a a and log a of range both they the are and state function inverses both 8 + a and 4 graphically 2 log domain and 5 − 2 log 4 7 50 a log 8 5 d y, a 2 and 5 b x 3 of log 3 ac 4 f (x ) = algebraically. + 1 6 (5 ) 4 3 b e 6 ln x f log 2 ln (x + 1) 3 ln (2x + g (x ) = log x − 2 6) 2 c 2 + 3 log 4 1 g 16 + log x − 2 log 7 2 d y = log (7 x ) − log 4 6 that log 3 = x and log a expression log 0.25 4 = y write (x + 5) 4 terms of x and b y Use properties equivalent describe log of logarithms expression the of for sequence the graph y the equivalent = log of x to each nd an function. Then transformations that give the 3 48 1 12 for f and g d expressions log 144 a a f ( x ) = ( 27 x ) log 3 4 e 27 b g ( x ) = ( x log − 9) 3 log a 16 E12.1 Go ahead and log in on graphs a log a down a in a c k (x ) 7 3 Given a − 1) 1 log each ln(3 x 3 7 3 h( x ) = − 3 4 2 61 of a 7 Let a = ln x, b = ln (x + 2) and c = ln 4. 13 Let log 3 = x and log a in Express 4 a in terms of a, b a + 2 c ln ( 4 x x and y, = y. Find expressions, for: 7 b log 3 + 8x ) 3 c log 7 49 3 Given that ln a = 8: 2 x ln + 4 x + 4 3 a ln d express log (x ) as a simple natural a 16 x 14 3 log 2 b x of c : ln and 7 a terms 4 x logarithm 2 4 e ln b 3 x express 3 log x ln( a ) as a single a + 2x logarithm. Problem solving 15 Reproduction in a colony of sea urchins can 0.03 x be 8 Express as a sum and/or dierence modelled by the N equation = 100e of where N is the number of sea urchins and x is logarithms: the ln ( x c ln 25) b ln( x d ln - 3x introduced - 28) a x + 1 x 8 2 x - 4 x days since the original 100 were the the reef. number of days it takes for the - 5 to double. 2 x + 6x + 8 b x Find to population 2 e of 2 2 a number - 10 x Find how many sea urchins were born on 24 - ln day 19. 3 x 9 Solve these 2 x a 4 x exponential + 1 Problem equations: x 3 + 3 16 = 10 × 3 A of 2 x b solving mathematician people calculated infected after the that rst the case number of a x 2 - 3 × 2 - 4 = 0 disease was identied followed the model 0.001t 10 Solve these logarithmic equations: P = P (1 - e ) where P is the number of 0 infected a log x + log 4 - a b log log a x - log 7 4 5 = log a = log x + log 9 (x 2 3 ) + log 9 (x and t is was identied. 1 - log ( x + 3) = log log (x ) = 5 a 9 ( x log - 5) - ( x log Calculate log 2 = x and log a and + 4 ) = 5 expressions = log y. Find, in terms In a of 2 city, b log 40 a 400 d a A game log log by taking logs of both sides: x 19 = 2 5x 2 2 6 2 1 = 25 b c city, take for case it be would 5% 2 2 5x = 80 of infected. people the are infected population after of in in Swaziland 2000, the and number 26 of recorded 15 rhinoceros rhinoceros in in 2011. the 2.5 nd x a 58 187 park follows 0.4 Solve the rst a a 12 long to Calculate park rhinoceros game e of the city. Assuming log after x the 5 c population days for : 17 a the of -1 a y, how population 21days. 11 is number x b e the 4 ) + 9 the d P 0 4 2 c people, 12 a d 3 6 = 111 E12 Generalization the function. an exponential function, N U M B E R Review In E6.1 and modelling the in E10.1 the Richter context you used magnitude M this of formula an for 2 earthquake using The pH value whether scale: value than I a of 7 7 is of a solution solution is is neutral, basic. To basic less is used to (alkaline) than calculate 7 is the determine or acidic. acidic, pH of a and A pH more liquid you c M = log 10 need I to know the concentration of hydrogen ions n + (H where I is the intensity of the ‘movement’ of ) in moles per liter (mol/l) of the liquid. the c earth from the earthquake, and I is the intensity of The n the ‘movement’ on a normal day-to-day basis. pH is then calculated using the logarithmic mol/l. Determine formula: + You can also write this as: pH = - log (H ) 10 M = log I 10 7 + a Milk has H 1.58 = × 10 I c where I is the intensity ratio whether milk is acidic or basic. I n b 1 a The San Francisco earthquake of Find the pH of + Shortly afterward, America greater Find magnitude had than the an 8.3 an on San magnitude Richter earthquake intensity the the ratio Francisco b A recent 7.5 on more in on South the in four South c scale Richter intense the sample H earthquake. Richter A of pool = 6.3 × 10 sample of water has concentration: 7 + times of mol/l. pool Determine the pH of the water. the Some chemicals are added to the water because America. earthquake the concentration: mol/l. scale. d earthquake with 3 = 1.58 × 10 H measured vinegar 1906 in Afghanistan scale. San Find how Francisco measured many times the answer the water is taken in is c indicates not after that optimal. adding the A the sample concentration is H Determine the level of chemicals, + earthquake pH of water and now the 8 = 7.94 × 10 mol/l. was. c Find how much magnitude is, if larger it is 20 an earthquake’s times as levels: intense on 7.0 if < pH water < is now within optimum 7.4. the + e Richter scale as another Find the range d Determine how earthquake whose much more intense is scale than magnitude an for H is 7.8 earthquake on 7.0 < pH < that give a pH in the 7.4. an 3 Richter values earthquake. The volume of (db) and the sound D is measured in decibels the I is intensity of the sound measured whose 2 in magnitude is Compare the , using intensities of two An anti-theft car 13 in 2008 with magnitude 6.0 Sichuan in 2008 with magnitude Jill’s scream Find scream How you have alarm has an intensity Find the volume of the was measured how than much 56 db, more and Jack’s intense the statement Jack’s. of inquiry? Give specic examples. Statement of Inquiry: Generalizing that can changes model in duration, quantity helps frequency establish and alarm relationships variability. E12.1 Go ahead and log in was Jill’s discuss explored of 2 W/m decibels. 48db. and I 7.6. b Reect = 10 log and in Eastern D formula earthquakes: 5.8 × 10 Nevada the 10 a e Watts/m 6.2. 2 63 Are we very similar? E13.1 Global context: Personal and cultural expression Objectives ● Idntifying Inquiry ongrunt triangls asd ● on questions What onditions ar nssary to F standardritria stalish ● ● Using ongrunt and similar triangls Why is ongrun? ‘Sid-Sid-Angl’ onditionfor provothr gomtri not a to ongrun? rsults CIGOL ● How an ongrun usd to prov C othr ● rsults? Whih is mor usful: stalishing D similarity ATL or stalishing ongrun? Communication Undrstand and us mathmatial notation 13 1 Statement of Inquiry: Logi our an justify appriation gnralizations of th that inras asthti. 13 2 E13 1 2 6 4 G E O M E T R Y Y ou ● should use already Dynamic (DGS) to Geometr y draw basic know how Software 1 a Use shapes of DGS side Use reections, rotations 2 translations = Describe that a A d D to with ∠ ACB and to construct lengths DGS ABC recognize T R I G O N O M E T R Y to: b ● A N D 4, 80° = and triangle 7 cm. triangle 40°, BC single a and construct ∠ ABC the 6 = 5 cm. transformation takes: to to B b A E e B to to C c D f C E to to D B y 6 B A 4 C 2 x 0 6 4 2 2 4 6 2 4 6 ● nd angles in parallel lines 3 Find of the the marked and ● nd lengths in similar triangles 4 size 110° angles a Triangles Find b a b ABC lengths and AC DEF and are similar. ED B E 5 3 Establishing F ● What ● Why onditions is Exploration congruent ar nssary ‘Sid-Sid-Angl’ not a to cm cm triangles stalish ondition ongrun? for ongrun? If 1 you ass 1 Us dynami gomtry softwar to do to triangl A with sids 5 b triangl B with a c triangl C with angls m, 6 m and 7 dynami onstrut m triangls sid of 8 m and all angls 60° and softwar, ths auratly 60° using 45°, hav onstrut: gomtry a not 75° pnil, ompasss and protrator. d triangl D with angls 40°, 60° and 80° and a sid of 5 m Continued on next page E13.1 Are we very similar? 2 6 5 e triangl E with sids f triangl F with on nd g 2 G, of a siz your xatly mor Two 4 m than shaps on ar sid 4 triangl triangls th m and m, 8 m, and and with an angl angls of of 50° 30° and 45° at ah sid right-angld Compar drw sam. with with othrs. Disuss possil on sid 4 m Idntify whih of th and whih hypotnus triangls dsriptions a 5 m. vryon to g lad to triangl. congruent if thy hav th sam sid lngths and th sam angls. Reect ● th 6 Ar and th discuss triangls in ah 1 pair ongrunt? a b 3.5 2.5 2 2.5 3.5 2 2.5 3.5 2 3.5 c d 60º 2 2 60º 40º 70º 45º ● ● Look at th diagrams you 3 drw rat triangls whih ar rat triangls whih might What sam Two do you all 40º 70º 45º in always triangls not that Exploration ongrunt, 3 1. and Whih whih dsriptions dsriptions ongrunt? hav th sam angls, ut ar not th siz? shaps rtion, ar congruent rotation or if on an translation, or a transformd omination into of th othr ths. y a Th word oms Latin working with ongrunt triangls you nd to idntify sids and angls: C F A 2 6 6 E13 Justication D ‘I agr’ th ‘I corresponding th Congruō, maning Whn congruence from om togthr’. or G E O M E T R Y Δ DEF D is DE is th is th ∠ DEF ATL Th th ≅ is symol so Using To th A this and of of notation and AB, of ≅ rst shap nd th sids, Example or DE lttrs Δ DEF to hlps into in th ar and so D AB of In th triangls ar ongrunt. vrtis. ∠ ABC ar onvntion ‘triangl your you sond, ABC to E , using is sids. orrsponding for ongrunt angls. triangl rotation, an C to triangl orrsponds to F ’. larly. idntify You ongrunt and working an vrtis. largst/smallst two orrsponding and orrsponds show th th T R I G O N O M E T R Y important. vrtis, th imags so ar ∠ DEF mans B you is lin, orrsponding ongrun. orrsponding th so A ∠ ABC, th Δ ABC Δ ABC D rprsnts ordr thn longst of so orrsponds idntify taks A, rtion statmnt DEF, of rtion th notation Th rtion imag A N D th transformation rtion also math or that translation, pairs of shortst/ angls. 1 N Δ PQR and Δ LMN orrsponding ar ongrunt. Idntify th sids. Q L P M R Δ PQR LN a rotation orrsponds ∠ L MN LM is orrsponds orrsponds The to to ∠ P. QR. The side opposite shortest side of each triangle. The obtuse angle in each triangle. the obtuse angle in each triangle. PQ. The last pair of sides. 1 qustions 1 Δ LMN PR. to orrsponds Practice In to of 1 to 4, idntify B th orrsponding sids ah pair of triangls. I 2 E in L 4 4 K 3 5 5 F A C D G H J 3 N 3 O X 4 Q T V R U M P S W E13.1 Are we very similar? 2 67 5 Idntify symol th pairs notation, of ongrunt with th triangls in orrsponding this diagram. vrtis in th Us ongrun orrt ordr. L W K N V O J X P Q M B C S F T R D H I A G To show on of that th two triangls onditions Exploration Th two 1 aim of this triangls Choos Now try original. 2 Rord a to ongrunt, is to disovr thr sid triangl lngths with onstrut anothr whthr rsults from sides 3 angles 2 sides angle show that thy satisfy what information guarants that or stp ould sid triangl not 1 it in of is a a triangl. that is not ongrunt to th possil. tal the mak lngths. two lik this: triangles and angles an and and between Now look did on triangls. 3 Always elements) th tal. YES or congruent? NO them angle them the between angles not the the between side 3 and between sides not 2 to elements 3 2 that ths (indicate 2 nd ongrunt. Sketch 3 you 2 Disuss th ar ongrun. xploration will any Construt for them a side them at th othr rows masurmnts Rord of for whthr or th not In lmnts it is th and possil sam try in to th way as in onstrut stp right-hand olumn. Continued 2 6 8 E13 Justication 1, dirnt on next page G E O M E T R Y 4 Basd to 5 on your Compar th two sids B, two th oth in in two Reect for two triangls drivd rsults from Exploration 1. th sam th angl two ongrun B, and A two ar is th twn th is th triangls sids lngths lngths triangls (ASA thr triangls, sam as th thr sids of (SAS): ar th triangl th ongrunt. and in or sam a thos ar pairs qual of sids is th ongrunt. siz as triangls lngth orrsponding AAS): ongrun hav two two orrsponding two sam as ar orrsponding sid lngth is (RHS): hypotnuss, in whos ongrunt. oth and triangls, on th of th two ongrunt. and how discuss th using Right ah 2 Angl-Hypotnus-Sid of th othr ongrun ongrun ondition an onditions. 3 Draw: a a lin b a irl c a lin In Δ ABC, sgmnt of AB radius from AB A = th 7 that 6 of lngth m m, BC m ntrd maks position 6 = of an 7 on angl m point of and C B 40° with ∠ CAB on your = AB. 40° diagram. Draw: a a lin b a irl c a lin In Δ DEF, Explain your 5 B, A ar ar ongrun oth ar Dtrmin 4 A triangls, Exploration 3 onditions (SSS): triangls right-angld triangls 2 nssary your Angl-Hypotnus-Sid rmaining Explain to triangl triangl triangl sam Right If 1 of two of angls angls th triangl in hr ongrun Angl-Sid-Angl If th congruence sids sids of sam ● rsults Sid-Angl-Sid If ● for thr triangl ● your Sid-Sid-Sid If disuss T R I G O N O M E T R Y ongrunt. Conditions ● rsults, A N D sgmnt of radius from DE why DE D = it 4 that 6 is of m EF 6 m ntrd maks m, not lngth = an 4 angl m possil on to E of and 40° with ∠ FDE dtrmin = th DE. 40° position of point F on diagram. Explain why Sid-Sid-Angl (SSA) is not a ondition for ongrun. E13.1 Are we very similar? 2 6 9 Example Prov that 2 in this diagram, Δ ABC ≅ Δ DEC. C E Givn: AB and ED ar D paralll Separate AB Prov: = are ED Δ ABC ≅ the given, question and the into part you the part need you to prove. Δ DEC Proof ∠ BAC = ∠ EDC (altrnat angls) ∠ ABC = ∠ DEC (altrnat angls) AB = DE Give a reason (givn) for Both sign Thrfor each Δ ABC ≅ Δ DEC th (=) statement. quals and ongrun ar usd that Example 3 ar to qual. that in a rtangl ABCD, Δ ABC ≅ Δ CDA us, sign or angls Both in though ar gnral som xaminations A (≅) indiat lngths aptal Prov th (ASA) or B shools you to instad D might us of xpt on th othr. C Draw a diagram. Givn: ABCD is a rtangl. Separate Prov: Δ ABC ≅ the question into the part you Δ CDA are given, and the part you need to prove. Proof ∠ ABC ar = ∠ CDA right angls. Δ ABC and aus AB ≅ 90° Δ CDA oth CD = ar hav aus Give right-angld hypotnus th opposit triangls with qual ≅ Δ CDA for each statement. hypotnuss sids of rtangl ar (RHS) are qual. could equal opposite 27 0 reason AC You Δ ABC a E13 Justication also (SSS) sides prove or by and this result using the the right by showing two angle all congruent in between the sides pairs of them (SAS). G E O M E T R Y Objective v. C: Organiz In Practice you 1 4, possible using a organize logial your str utur answers whthr onditions for th triangls in ah pair b c d Prov to help make sure that that ar ongrunt. If thy ar, stat ongrun. a a systematically triangles. 2 Dtrmin th 2 question all Practice T R I G O N O M E T R Y Communiating information 2, include A N D Δ PQR is ongrunt to Δ STR S Q R T P b Prov that Δ GHK ≅ G Δ JHK. H K J c In of triangl AB. ABC, Prov CD that is th Δ ADC prpndiular is ongrunt to C istor Δ BDC A 3 A rgular to Δ CDE pntagon has vrtis ABCDE. Explain why D Δ ABC B is ongrunt In 3, lal hlp Problem 4 A rgular ongrunt a and diagram you. solving hxagon to draw has Δ ADE. vrtis Stat th ABCDEF. ondition List usd all to th triangls stalish that ar ongrun. E13.1 Are we very similar? 2 71 to Example Cirls C 4 and C 1 hav ntrs O 2 rsptivly, and and O 1 intrst at C points X X C 1 2 and 2 Y O O 1 Prov that Δ O XO 1 is ongrunt to Δ O 2 2 YO 1 2 Y Givn: irls and C C 1 with ntrs O 2 and O 1 2 Separate rsptivly Prov: Δ O XO 1 ≅ intrst Δ O 2 C points X and into ‘given’ and ‘prove’. Y. YO 1 X at 2 C 1 2 O O 1 Draw the triangles Δ O 2 XO 1 ≅ 2 Δ O YO 1 on the diagram. 2 Y Proof Give O X = O 1 O X = O 2 O O = radii of C XO (oth radii of C O (sam lin sgmnt) 2 Δ O 2 YO 1 Practice ) 2 1 ≅ ) 1 Y O 2 1 ATL (oth 2 1 Δ O Y 1 a (SSS) 2 3 A 1 Triangl M is th Prov ABC is isosls midpoint that of Δ ABM with AB = AC BC. and Δ ACM ar ongrunt. C 2 Points Th A, B, hords Prov that C and AB D and Δ ABO li CD and on ar a irl qual Δ CDO with in ar ntr M B A O. lngth. ongrunt. C O B D 3 PQR is atan 4 Points Prov 5 an isosls angl Cirl A, B that C of 90°. and C Δ AOB has triangl Prov li on and ntr with that a irl Δ AOC A, and PQ = Δ QPX ≅ with ar QR. A lin from Q mts PR at X, Δ QRX. ntr O ∠ ABC = ∠ ACB. ongrunt. irl C 1 has 2 D C 1 C 2 ntr of C of C . B whih Points D lis and on E th ar irumfrn th intrstions 1 and C 1 Prov B A 2 that Δ ABD and Δ ABE ar ongrunt. E 272 E13 Justication reason for each statement. G E O M E T R Y 6 HIJK is a squar. H and J li on a irl with ntr A N D T R I G O N O M E T R Y F H Prov that Δ FKH and Δ FKJ ar ongrunt. I J 7 Prov that if lins PQ and RS ar paralll, and X is th Q midpoint of PS, thn Δ PXQ and Δ SXR ar ongrunt. P X S R Using C ● All How an mathmatial known usd as to formalizd Th rst axioms. prov of In y Grk gomtry othr othr Thr start ar gomtry; th th ongrun systms axioms. dsri congruence words, y usd in this to dirnt most prov topi assums som th to agrd of around fats. axioms 300 and Ths whih gomtry, ongrun tru, results rsults? Eulidan Eulid taks thm is other othr systms famous mathmatiian it prove stalishing many th to ar an whih was bce. onditions thn uss to thm Eulid’s to famous rsults. is his The Exploration puliation Elements In th ist that diagram, ah PS othr Δ STU ≅ and at U. TQ ontaining P dnitions, thorms Δ PQU cm 12 th lngth of ST . 9 rasoning. Idntify Δ STU th and ongrunt Δ PQU. angls Justify Q known, a you an singl him R S If prov two triangls ddu using aout Corrsponding this as part of a SSS, th SAS, othr parts of proof, of th th ASA/AAS ongrunt an of Eulid’s thm in arnd modrn “th ar orrsponding you alrady pla niknam fathr ongrunt ut gathring in your rasoning. 4 wr U cm T 3 Many Justify rsults your and cm proofs. Find of 13 mathmatial Prov 10 2 – 4 ooks 1 most ahivmnt or triangls writ RHS, angls ar CPCTC xplain and sids ongrunt. for what in th you of gomtry”. an triangls. Whn using short. E13.1 Are we very similar? 273 Reect and discuss Th 3 isosls triangl Rad and disuss this proof to mak sur you undrstand was Isosceles triangle theorem pons known Δ ABC is isosls with AB = AC, thn ∠ ABC ≅ ∠ ACB. as th asinorum, ‘ridg If thorm it. of or asss’, A aus studnts Proof in AB = AC mdival who (givn) ould not undrstand ∠ BAC = ∠ CAB (th sam = AB ≅ Δ ACB (SAS) wr ∠ ABC ≅ ∠ ACB (CPCTC) B Copy 4 this proof and add th rasons. Theorem If ABCD is a rhomus thn ∠ DAC ≅ ∠ BCA A Proof AB = CD, AC = CA Δ ABC BC = DA ∠ DAC ≅ aus aus ≅Δ CDA aus ∠ BCA B aus D C 2 Δ ACE B lis Copy is an on isosls AC and and D omplt Theorem right-angld lis th on C E proof triangl suh that that with BE ∠ CEB ≅ = th right angl at C. DA ∠ CAD. ____________________ Proof A BE = DA ∠ BCE = aus ∠ DCA = 90° aus B X CE = CA Δ BCE aus ≅Δ DCA aus E C ∠ CEB 2 74 ≅ ∠ CAD aus E13 Justication was a ndd, thought to This C of 1 why ignorant. proof Practice or (givn) proof Δ ABC th angl) proof, AC tims D is y Pappus Alxandria. G E O M E T R Y Problem 3 Copy and A N D T R I G O N O M E T R Y solving omplt this sklton proof. Theorem If Δ ABC is isosls prpndiular to with AB = AC whr th angl thn th angl istor of ∠ BAC is BC Proof Lt X Show AB = th that AC ∠ BAX ∠ Hn ⇒ × ∠ BAC mts BC. Draw Δ ACX : Give a reasons diagram, to prove showing congruence. . Δ ABX ∠ AXC Δ ACX AXC. ∠ ≅ ∠ ___ ≅ = = 180° ( ). ( Give ). the condition Explain aus for the congruence. reason for this. . 180° ⇒ Thrfor 4 Copy and th angl omplt istor this is prpndiular sklton proof. to Inlud BC. a suital diagram. Theorem If AB OM is is a hord to a irl prpndiular to C with ntr O, and M is th midpoint of AB, AB Proof OA = AM OB = aus BM is Hn ∠ ∠ + 2 . aus . ommon. Thrfor ⇒ X. . aus ∠ + 2 ≅ of ommon. Thrfor ∠ Δ ABX istor aus ≅ is point Δ OAM ≅ ∠ × ≅ Δ OBM ( ). ∠ = aus . = ⇒ Thrfor OM is prpndiular to AB E13.1 Are we very similar? 2 75 5 Cirl C has ntr O L is a tangnt to C at X L 1 L and L 1 mt at is a tangnt to C at Y 2 Z. 2 a Skth L , L 1 b Prov c Hn and C. Mark points O, X, Y and Z on your diagram. 2 that triangls show that Δ OXZ XZ = and Δ OYZ ar ongrunt. YZ Tip 6 A paralllogram is dnd Prov that opposit Prov that th sids as ar having qual two in pairs of paralll sids. lngth. In 6, divid th paralllogram 7 diagonals of a kit ar two 8 Prov 9 Squar X is that th diagonals TUVW th is midpoint of a intrstd of AD and paralllogram y th also straight th into prpndiular. ist lin midpoint W ah othr. ongrunt triangls. ABXCD. of UW T D C X B A V Prov that ∠ AWB Problem 10 Th 28 km th uildings. of ∠ DUC solving Pntagon, largst ≅ U hadquartrs It orridors, taks and th has of th shap an of US a intrnal military, rgular is among pntagon, ourtyard aout th world’s ontains th siz of ovr Tip thr Rmmr Amrian A is statu footall (K ) is quidistant Prov (A that and it plad from is also dirtly th two in front narst quidistant of on ornrs from th fa of nxt of th uilding, th uilding two ornrs (D of and th so that it E ). uilding C ). C K E B A Using ● similarity Whih is mor usful: to prove stalishing other similarity or results stalishing ongrun? You hav gomtri to sn how rsults. important 27 6 stalishing Somtims, mathmatial ongrun simply rsults. E13 Justication an lad stalishing to th similarity proof is of othr nough to is quidistant A and that D D that ‘P lds. lad B ’ AP = from mans BP G E O M E T R Y Exploration 1 Copy and sgmnts of a omplt irl point X If T R I G O N O M E T R Y 5 ratd Theorem: A N D A, suh this y B, C that intrior to proof to intrsting and th th D ar hord irl, disovr th rlationship twn hords. points on ABmts th th irumfrn hord CD at thn C A B X Reproduce the diagram showing Δ AXC and Δ DXB O D ∠ AXC = ∠ aus . Show ∠ CAB ∠ ACD Sin = ∠ CDB = all know aus aus ∠ thr that angls Δ AXC is that corresponding angles are equal. . ar . qual, similar to w Δ DXB AX = Corresponding sides of similar triangles are proportional. BX Rarranging Reect ● Ar all Justify ● Whih givs: and discuss similar your is . triangls This the ‘intersecting chords theorem’. 4 ongrunt? Ar all ongrunt triangls similar? rasoning. mor usful: stalishing similarity or stalishing ongrun? Summary Two sid shaps ar lngths and congruent sam siz if thy hav th ● sam angls. Angl-Sid-Angl If two two Two shaps ar congruent if on an into th othr y a rtion, translation, or a omination of for orrsponding a orrsponding oth triangls, Sid-Sid-Sid Right th thr ongrun as sids th of thr triangl sids of A ar th triangl If two th ar is th two sids ongrun of triangl orrsponding angl oth sid th whos two lngth triangls right-angld and sam triangls is thr th sam ar ongrunt. ongrun on of triangls th hav rmaining qual two ar lngth in oth triangls, th ongrunt. twn triangls, sids thos th A ar of pairs two th sam triangl of parts of ongrunt triangls ar (SAS): ongrunt. two as and ongrunt. Sid-Angl-Sid If B, two Corrsponding ● triangl AAS): siz sam B, two triangls or sam (SSS): sids lngths in (ASA th Angl-Hypotnus-Sid hypotnuss, If angls ar congruence (RHS): ● A ths. ● Conditions ongrun triangl rotation in or in is transformd angls sids triangls B, is ar lngths and th You an writ CPCTC for short. as th sam in ongrunt. E13.1 Are we very similar? 277 Mixed 1 Ar If th so, practice two giv prov triangls th in ah onditions for diagram ongrunt? ongrun usd 4 to ABCDE of it. CD. is a rgular Prove istor that pntagon. AX is th X is th midpoint prpndiular ofBE. A a b Y X B A W C D B E Z c d T R E S D To prov AX is X th C prpndiular istor of F G I BE, show that AX is prpndiular to BE and U that V 5 X Part is of joining a In th diagram, givn that AD = BC an midpoint origami paralllogram H 2 th th and two = ∠ ACB, prove that ∠ ADC ≅ onstrution thr most fold distant onsists lins: on ornrs of of a diagonal and two short paralll th lins ∠ ACB joining A BE and paralllogram, ∠ DAC of th othr ornrs to th diagonal, as B illustratd. D b In is th C diagram, paralll to givn IGH, that prove E F that ists IG, and E I Prove ∠ FEI ≅ ∠ GFH that th short paralll lins ar qual in lngth. E 6 Th diagram shows points A, B, C and D. G F Prove I that triangls ABD and ACD ar ongrunt. H A c In th MK diagram, ists givn ∠ JML, that prove ∠ J = that ∠ L and Δ JMK ≅ that Δ LMK J D K M C B L 7 In th and 3 ABCDEFGH is a rgular otagon. By diagram, CAB = 60° AB is paralll Prove that to DE CDE is and an AB = AC isosls onsidring triangl. Δ AEF and isosls Δ ADE, prove that Δ ADF is an A triangl. F B E D G C C H A 278 B E13 Justication D E G E O M E T R Y 8 A small larg frams, mast of lvl is formd frams illustratd lngths on radio triangular mtal: low, AC, y togthr. is AD, joining thr On th mad BD of from and CE. 11 thr xd four It Railway traks ountris stands Th ground. Th in th Limrik, th rails ar paralll gaug. uss 1600 shows Irland. an T R I G O N O M E T R Y a lins mm railway viw of a gaugs. Irish Gaug, apart. juntion Thdiagram ovrhad at Dirnt national Irland photograph rprsnts in th dirnt of two st alld hav Rpuli whr A ar distan, A N D low th it layout of lins. E B C Givn and that BD AD and thatlngths 9 A King and Th or is AB king post that AC ar for ar qual and Truss suital mtal and CE Post D AE ar Bridg short PQ is hlps a qual in in lngth, lngth, prove qual. has a simpl strutur spans. singl prvnt pi th of ti wood am B ABfromsagging. P C A F D G E Q Prove that kingpost thn AP ∠ PAQ if PQ and = Q is is th midpoint vrtial, BP must and of AB qual AB, is in H th horizontal lngth and Assuming ∠ PBQ. and 10 all of th Irish that Δ ABD b prove that Δ BAC c hence show d prove that of Th thr qual ah an lads lngth pair. and Prove quilatral of a wind hav that th th triangl. turin sam tips of ar angl th all of twn lads form ars at laddr opn ars Use ongrunt and paralll, to Δ CDB Δ BCA ABCD ≅ is a Δ EFG ar to rhomus givn that th paralll. a stpladdr idas of on oth sam mak ongrun positioning hight that th on th how sam nsurs out is ≅ Δ ABC larly th straight solving stal. explain that traks horizontal mor Gaug: prove Problem Th to a twosts 12 traks oth sids th horizontal sids of th of th laddr angl. E13.1 Are we very similar? it to 279 13 Similar Angl triangls Bistor an usd Thorm. to Copy dvlop and th Proof: omplt Draw this PT paralll to SR. proof. T P Theorem: a triangl An angl divids sgmnts that twosids of ar th istor th of opposit an angl sid proportional to in th of two othr Q triangl. P S R Q S ∠SQR = ∠PQT ∠RSQ = ∠ aus aus R Givn: SQ is th istor of angl S ∠ SR = ∠TPQ aus QR = Prov: SP QP Sin w all thr know angls ar that qual, . SR = QP ∠PST Hn = ∠QSR ∠PST Thrfor, PS SR SP E13 Justication ∠PTS = PT QR = Hn, 2 8 0 = aus QP aus aus G E O M E T R Y Review Th anint ultur to and rat in art A N D T R I G O N O M E T R Y context of origami involvs modls. has folding Som roots at modls in shts ar Japans of Th rsulting papr dsignd rass ar illustratd A in this B diagram. C to E rsml just animals, lrat th owrs auty or of uildings; gomtri othrs dsign. D F H G Th Z artist thinks lngths FH and DY ar qual. 1 b Explain why EX = EG. 2 1 An origami and folds it artist in taks half, a squar sht of c Hence d Explain why Th and to artist folds th runs top up h sht at mt as from folds th a th ongrunt unfolds to dg, straight Finally, th thn it folding two th th of sht sht, ornr ras hight nd ∠ EGX Δ GED ≅ Δ GZD Find f Show that GF g Show that ∠ GFH h Hence and ∠ DGZ ∠ YED show and DY = EY that ar = ∠ EYD th artist’s qual – is laim – that lngths orrt. half taks lin, Th to on not fold th paralll th in ∠ EGD rtangls. ntr illustratd. on why nd e FH produs to papr, Fold Explain trigonomtry asshown. Hn a use to foldd ornr quit ratd opposit th top sid. dg of ornr. Reect and How hav you Giv spi discuss xplord th statmnt of inquiry? xampls. Statement of Inquiry: Logi our an justify appriation gnralizations of th that inras asthti. E13.1 Are we very similar? 2 81 A E14.1 world Global context: Objectives ● Solving of dierence Identities Inquiry quadratic and rational inequalities and relationships questions ● What ● How is a non-linear inequality? F both ● algebraically Solving other and graphically non-linear inequalities do you inequalities solve non-linear graphically? graphically MROF ● Using mathematical non-linear models inequalities to containing solve ● How ● Which does a model lead to a solution? C real-life problems is more ecient: a graphical D solution ● ATL Use Can or good an algebraic decisions be one? calculated? Critical-thinking models and simulations to explore complex systems and issues 11 1 14 3 E14 1 Statement Modelling of Inquiry: with representation 2 8 2 equivalent can forms improve of decision making. A LG E B R A Y ou ● ● should solve linear sketch already know how inequalities graphs of linear, 1 quadratic, to: Solve 2 −3 x Sketch − 2 < 5 − 4 x the graphs of : 2 rational, radical, logarithmic exponential and y a = x x + 3x − 4 y b = 2e functions − 3 2 c y = y d 4 log 2 x = 4 x e y 2 x 3 3x + 6 y f = = x − 5 2 ● solve quadratic completing the ● What ● How Objective apply D: the by 3 Solve x + 6x + 3 = 0. square Non-linear F iii. equations is a do non-linear you Applying selected inequalities solve in one variable inequality? non-linear mathematics mathematical in inequalities real-life strategies graphically? contexts successfully to reach a solution In Exploration 1, when you have selected your solution to the quadratic inequality, determine 2 graphically if the range of Exploration In ski ‘y’ jumping, as far as the hip angle guarantees a lift area of at least 0.5 m 1 athletes possible. descend The a angle take-o of the ramp, skier’s jump hip a o the end determines of the it and ‘lift ATL 2 area’ A (in between 1 Use m hip this ) which angle determines and function to lift area write a how can be far the skier modelled mathematical jumps. by the model The relationship function: (inequality) of the 2 2 3 range of Use GDC a the hip to angle graph both sides of this a lift area inequality of at and b the region of the graph that models the set of points c the region of the graph that models the set of points write least 0.5 m nd: point graph, graphs ensure the your both would a From where that intersect where where . down: 2 a the range b the range of the skier’s hip angle to ensure a lift area of 0.5 m or more 2 4 Explain ranges of how in the you step the skier’s can test hip angle whether that or gives not you a lift have area less selected than the 0.5 m correct 2 Rearrange 6 Graph A(a) , and explain how you would use the inequality to answer step 2 7 Explain how inequality you could in use step this 1 to the graph to form A(a) 5 check ≥ your 0. answer. E14.1 A world of dierence 2 83 Reect ● How do graphs ● and method original inequality? To ● solve ● a Graph or f the 0 the ● Choose a test your point this x-values satisfy to x-intercepts, you prefer: and the include as in one compare, x-values step where or the 6) in you one where your two solution graph where the each you set? side of rewrite the of the graphically: inequality, or rearrange into the form f ( x ) > 0 graph. points solution point in the Example Method not of intersection of both functions, or nd the zeros function. check the or inequality sides and To Solve did the inequality both < whether (or quadratic ( x ) 1 Explain. Determine of know intersect Which the you discuss in in this algebraically: the the region you inequality. region inequality, satisfy then the test think If it satises satises the inequality. the x-values If in the inequality, inequality, your the test other and then point the does not region(s). 1 inequality . Check your solution algebraically. 1 1.1 Graph both sides of the inequality and 60 2 f (x) = 16 + 12x − x 2 determine the points of intersection. 50 40 (1, 27) (12, 16) 20 f (x) = 28 − x 1 10 The x-values than 0 those of on points the on the quadratic line (LHS) (RHS) for are 1< x lower < 12. x 2 Test a point with x-value between 1 and 12: Select When x = an check that original 26 The ≤ x-value 36 ✔ solution is it the satises inequality endpoints (x = solution 1 the was interval, and x E14 Models on next inequality. “less = . Continued 2 8 4 in and 2: page 12) than are or Because equal included. the to”, the A LG E B R A Method 2 Rearrange to f ( x ) . ⇒ 1.1 y Graph the quadratic function. 35 2 f (x) = −12 + 13x − x 1 30 25 20 15 10 5 (12, 0) (1, 0) x 0 4 2 6 8 10 12 14 The The solution is zeros of f ( x ) for the Select Check: When x = 2: Solve the Method quadratic are x = 1 and x = 12. an x-values x-value between in the these solution zeros. interval, . and Example the . check that the inequality is satised. 2 inequality Check your solution algebraically. 1 1.1 y 2 f (x) = x x − 6 2 Graph 2 the both points sides of of the inequality intersection of the and determine graphs. x 3 2 1 1 2 3 4 2 (2.47, 2.35) 4 ( 0.808, 4.54) 6 8 2 f (x) = −2 x + 4x 1 The x < −0.808 or x > blue curve, for lies below the 2.47 red curve in the regions x < −0.808, x > 2.47. Check: When 6 < x = −1: = 3: LHS = −6, RHS = − 4 −4 When x LHS = − 6, RHS = 0 Continued on next page E14.1 A world of dierence 2 8 5 Method 2 Rearrange to f ( x ) > 0. ⇒ 1.1 y 2 f (x) = 3x − 5x − 6 1 6 4 2 ( (2.47, 0) 0.81, 0) Graph 0 2 the quadratic function. x 1 1 4 6 8 x ATL <−0.808 Practice 1 Solve or x > 2.47 The quadratic is greater than 0 above each inequality graphically, and check your answers algebraically. Use x d x 2 − 2x − 9 > 2x + 3 whichever 2 2x b − 5 ≤ x + 1 c 5x − 10 ≥ 23 x method 2 2 For 2 + 3x − 8 < astronaut 4 − 2x − training, 2 x 2 2x e − 7x weightlessness is + 7 > 8x − 2x simulated in a + 1 reduced gravity 2 aircraft that models the of the ies in a parabolic relationship aircraft in aircraft’s height a Write an b Determine aircraft how in The above inequality ies between meters. is The the ight the time t (t ) = in −3t + 191t seconds, experience and + 6950 the weightlessness height when this astronauts situation. experience weightlessness when A rectangle Write 4 A and is 6 cm solve gardener has longer the arc. an 24 than inequality meters of it to is wide. nd fencing its to Its area possible build a is greater than 216 cm dimensions. rectangular enclosure. 2 Theenclosure’s inequality 5 For to a to drivers visual area nd aged should possible between stimulus be 16 (such less lengths as and a than of the 70, trac 24 m . Write and solve an enclosure. the reaction light) can be time y (in modelled milliseconds) by the function 2 y = 0.005 x inequality than 25 − 0.23 x to determine milliseconds, Problem 6 A baseball time t + 22 , (in where the and ages x is the for driver’s which a age in driver’s years. Write reaction time an is more solve. solving is thrown seconds) from and a the height height h of 1.5 (in m. The meters) of relationship the baseball between while in the the 2 air is modelled a Write b Determine 2 8 6 an by the function inequality how that long h (t ) = describes the E14 Models baseball −4.9t how is in + 17t long the + 1.5 the air. baseball is in the air. h the m. describes parabolic h function astronauts 9600 that long a arc. 2 3 x-axis. 1 2 a the you prefer. A LG E B R A 7 In a the right-angled other. The Determine 8 A 2 the cm the possible square sides are triangle, one hypotenuse is cut then is of lengths from folded for each up the more to perpendicular than the the shortest corner form twice of an a is of 2 cm the longer shortest than side. side. square open sides length box. piece Pia of card, needs a and box with 3 maximum Example Find the volume 40 cm . Find the smallest possible dimensions of the box. 3 set of values such that in the domain and check The your solutions Examples 3 to and 4 answer. can also using 1.1 be the found same Method 2 approach y as described in 4 Examples 1 and 2. 1 3 f(x) = x 2 f(x) = √x Graph both sides of the inequality, 1 and nd the point of intersection. x 0 1 2 3 4 5 6 Select in the interval 0 < x < an interval Check: When Example x = 0.5, x-value in the solution 1. and ≈ 0.707 < and test it in the inequality. 2 4 Solve , and check your answer. 1.1 y 10 x = 5 2x − 8 f (x) 7 = 1 x − 5 6 Locate 4 f (x) = 3 2 (blue) 2 0 where the LHS function (8, 3) RHS function (red). (3.5, 0) x 2 4 6 or Continued on next page E14.1 A world of dierence 2 87 Check: Select When x = 10, and and When x = 0, Practice 1 Find the , an and check . 2 set of values that satisfy each non-linear 1 inequality: 1 a − x < 0 b x − 4 ≥ 0 x x + 6 c > d 2 ln x < ( x log − 2) 2 x +1 1 4 2 x e > 2x + 3 < f x + 5 2x + 3 3x 1 ≥ h < x x x When two resistors, R and R + 4 are connected modelled by the as shown, the total resistance 2 1 is x solving 1 R 3+ −1 + 3 Problem 2 x 1 g 1 equation = 1 + R R R 1 2 + R R 1 a R 2 ohms = and R must be at least 2 1 ohm. Find R 2 b R 1 = 2.2 ohms and R must be at least 1.7 ohms. Find R 1 C 2 Non-linear ● How does a inequalities model lead to a in two variables solution? When you solve an inequality in one variable, When you solve an inequality in two variables, the solution the is solution a is set a of set x-values. of points. 2 For this graph of y = x − 2x − 3, the blue shaded area represents the set of 2 points that region by satisfy y < substituting x − 2x the − 3. You coordinates can of a test that point in you this have the region correct into the original 2 inequality. correct For region example, is for the point (0, 4): x − 2x − 3 = −3 > −4, shaded. y 8 6 2 y = x − 2x − 4 3 2 x 10 8 6 4 2 2 4 6 8 2 8 8 x-value in each region, . E14 Models so the in the original inequality. A LG E B R A The unshaded region of the graph on the previous page represents the set of 2 > with a dashed solution solve ● Graph ● Select show non-linear the a that values point is region (e.g. on − the . The line quadratic are not graph included is in drawn the that is inside the not If by on the the in the the is variables: equality. curve inequality curve). point two not If the (e.g. and is substitute true, shade inequality outside the is the the not values region true, into where shade the the the curve). 5 sketching the dened inequality. where Example inequalities region point original Shade to x set. To By line, − a suitable region graph, containing solve the the inequality possible solutions . on your graph. Factorize to nd the roots of f ( x ) = 0. ⇒ ⇒ Use x-coordinate of the formula coordinates Vertex = (3.5, to nd the vertex of the vertex. 2.25) y 3 (3.5, 2.25) 2 Draw 1 line, (3, 0) the as it parabola with represents a a dashed true inequality. x 0 1 1 2 y < − x + 7x − 10 2 Check: For (3, 0): , hence Test the region shaded is a then Practice point in the original shade 3 the correct In Sketch a suitable graph and shade the region on the graph that shows of the > x + 3x − 1 b y ≤ − x ( d y > ln ( x a line − 2) + 3 e y ≤ e x the is dotted graph as above. 2 2 2 y of inequality. in a case inequality, the the solution region. the strict 1 inequality, correct. + 3x − 2 c y ≥ + 1) − 3 f 4 − 3x x + 3 x 3 − 2x In ≤, the the case of graph ≥ of or the y < quadratic a solid E14.1 A world of dierence would line. 2 8 9 be 2 Write an inequality to describe the shaded region y a in each graph. y b 10 10 2 y = −x − 4x + 5 8 8 6 4 4 2 2 2 y 4 3 2 1 14 2 1 0.5 x + 2x − 1 12 10 8 6 4 2 y y d 8 8 6 6 2x y = e + 1 − 4 x 4 y 4 = x − 2 2 2 0 8 6 Problem 3 For each i nd ii write 4 4 4 4 10 2 2 2 c x 0 x 0 6 = 2 0 x 2 4 6 8 10 10 8 6 4 2 x 2 2 2 4 4 6 6 8 8 4 6 8 10 solving graph: the quadratic an function inequality that for the describes parabola the shaded y a region. b y 3 4 2 3 1 1 0 4 3 2 1 x 1 1 0 5 4 3 2 1 1 3 2 3 c y 20 16 12 4 0 2 1 x 1 7 4 8 2 9 0 E14 Models x 1 2 A LG E B R A 4 A parabolic dam Themaximum and the length is built height of the of across the dam a river, dam across as above the shown the river in water is 90 the graph. level is 3 m, m. y 5 4 3 (45, 3) 2 1 0 x 10 a Write b State c Write a quadratic the domain an 20 function and inequality that range that 30 of 40 50 60 models the denes 70 the region 90 parabolic quadratic the 80 arch of the dam. function. between the dam and the river. D inequalities ● Which ● Can is good Exploration 1 Factorize two 2 For the linear the can two the intervals the the or an algebraic one? in the inequality to You the is into be less need to inequality the solution than solve in to zero, the step the 1 one two and factor cases solve original must be separately. each one. inequality. graphically. quadratic inequality algebraically by rst nding the zeros function. function zeros by a for case answer solve quadratic hence in also cases which quadratic solution . factors and Checkyour The two negative. 2: Determine the of one Case 4 graphical calculated? function and the be a that 1: Create of such Case 3 You decisions quadratic factors and ecient: 2 product positive more of the roots inequality to in Exploration function of the < x = equation. determine x are if it 2 factorizes 4 and Choose satises −1 x 1 < x < = into -1. an ( x - 4 ) ( x + 1) , The x-axis x-value in is each divided into interval, test it theinequality. x 4 > 4 x 3 2 1 0 1 2 3 4 5 6 E14.1 A world of dierence 2 91 Inter val Test x < point −1 1 < in 4 x − 3 × − 2 − 4 = 0 6 4 2 − 3 × 0 − 4 = −4 − × 7 − 4 = 24 24 > 0 6 > 0 4 No Is > 7 2 2 ( −2 ) < 0 2 Substitution x < 0 Yes No 2 The values Written in satisfying set Reect ● How ● Do ● Which notation, and would you you prefer two To solve ● Rearrange ● Factorize ● Place ● Select original the the inequality. If Repeat To check ● Choose a test point for your this x-values Solve the in all If − 3x : 1 < x − 4 < < 0 −1 < are the need in graphical to of < 4. and nd its the graphically? this to for this question? solve inequality? algebraically: either of 2 approach consider set that on Exploration a line, intervals inequality inequality is ( x ) < 0 or f ( x ) > 0. zeros. number the f is false, dividing and true, then it substitute then it is that into it intervals. into the interval is part of not. solution in in this algebraically: the the region you inequality. region satisfy think If the it satises satises the the inequality, inequality, and then the inequality. 6 quadratic inequality and check your answer graphically. Continued 2 9 2 x 4}. intervals. point in the one {x so x-values x-value or solution inequality quadratic is inequality you the inequality two ● is set 2 the would x inequality solution algebraic What the solution. Example the quadratic an the solve cases these quadratic discuss algebraically? a the E14 Models on next page A LG E B R A Method 1 For a product to be positive, the and factors ⇒ and must have the same signs. , ⇒ Because both the less value than 4 of and x needs less to than be 3, and using ⇒ and x < -3 covers all possibilities. , ⇒ As Check your solutions by sketching a of graph. before, the using x > inequalities, 4 x covers > 4 and both x > -3. y 10 2 y = x − x − 12 From the graph, solve the original you can see inequality that both cases since 5 when 0 5 4 2 x < -3 or when x > 4. x 1 1 3 4 5 5 15 The solution Method The is x < -3 or x 4. 2 zeros of are Inter val Test > x x = < point Is > Hence, f Which 0? table, ( x ) Reect = 4. -3 3 < x < 4 x 0 > 0 for and your > 0 12 Yes the algebraic Explain x > 4 5 in 8 the and 4 Substitution From -3 solution x < -3 is or discuss method for x x > < 8 0 No < -3 or x > > 0 Yes 4. 4. 3 solving quadratic inequalities is more ecient? reasons. E14.1 A world of dierence 2 9 3 Practice 1 Solve 4 these quadratic inequalities algebraically 2 − 2x − 3 ≤ 0 b x d x 2 c 12 + x − 10 x + 16 > 0 ≥ 0 + 6x ≤ 40 2 2x + 5x < 3 3x f − 1 > 2x 2 g 2 graphically. 2 − x 2 e conrm 2 x a and 6x One the + 4 x of the other. + 1 < 5x + 3 perpendicular Determine the sides of a possible right-angled lengths of triangle the shorter is 3 side cm longer that give than a 2 triangle with Problem 3 Each area a −1 < c x x than 4 cm . solving inequality quadratic less is the solution set of a quadratic inequality. Find a possible inequality. < 1 b x < −1 or x > 2 2 1 ≤ 2 or ≤ x ≤ x ≥ 10 x d < x or > − 3 2 1 e 6 3 Exploration 1 By using square’, 2 From the the quadratic solve the Conrm 4 Write 5 Check the roots solution 3 to your out 3 the that formula of the the the method steps of ‘completing equation in step 1, explain a how and you each to solve a non-factorizable steps work when quadratic inequality. solving: 5 inequality algebraically, accurate to 2 1 a x c 2x 3 5x + 1 > 0 b x + 2 x 3x – x 3 ≤ 0 d 3x 5x 5 ≥ 0 f < – 7x + 2 0 > 2x + 4x + 2 2 – 2x 1 < 0 2 i 2 0 2 + 2 g 6x 2 + 2 e s.f. 2 – 3x 2 9 4 h x j x 2 – 2x + 1 < x + 10x – 5x ≥ −8 2 + x obtain graphically. b Solve would b a Practice the . inequality solutions your or equation – 1 E14 Models ≤ −1 ≤ 0 A LG E B R A Problem 2 Solve of the each solving inequality. quadratic Explain your result by x c x the discriminant ∆ 2 2 a considering function. + 2x + 1 ≤ + 2x + 4 0 b x − 4 x + 4 ≥ 0 2 2 Reect How ∆ 2 can > 0 and the Example d discuss discriminant (x − 1) − 3 < = b 4ac 0 4 help you solve quadratic inequalities? 7 Solve , and conrm your answer graphically. Rearrange and simplify. A fraction and Method Case 1: when have the and signs. , hence , hence and Then and Solution or x < −1. 2 Find and the the x-intercept asymptote by by setting setting the the numerator x < −1 1 < x < x > to the 2 Substitution Yes x < 1 No Yes −1 or x on next right, these and values. page E14.1 A world of dierence 0. intervals > Continued 0, to into Is Solution: 0 to equal the left, between point equal denominator Consider Inter val Test numerator opposite and 2: Method negative 1 Then Case is denominator 2 9 5 Check: 1.1 From the graph, x-values greater 6 4 f (x) = 1 2 2 (0.5, 1) x 6 4 0 2 2 2 f (x) − x = 1 x + 1 4 Reect ● is ● more Does of Solve x 1 x the type of and 5 method explain inequality algebraic method for your solving reasons (quadratic, to rational, inequality algebraically and check 0, x ≠ 1 > 0, x 3x you feel aect your choice 8 x x 2 5x + 1 < 0, x Determine 5, x ≥ x Problem 2, x ≠ −1 ≠ 2 8 f ≠ 0 graphically. 6 ≤ 1 solution + 1 d ≠ 4 x 2 + ≥ 4 e etc.) your b +1 x inequalities 6 x c rational why. use? x < a x algebraic ecient, each 1 + discuss which which Practice 1 and Decide 2, x ≠ 5 5 solving the numbers that can be added to the numerator and 2 denominator of the fraction so that the resulting algebraic fraction is 3 1 always less than 2 3 Gretchen currently would scores consecutive bring her 2 9 6 f ( x ) is below 1 y free like to about throws average up improve 9 to free she would 70%. E14 Models her throws free in throw 20 need average trials. to in basketball. Determine successfully how make in She many order more to than f ( x ) for 2 0.5 or less than 1. A LG E B R A Summary To solve ● Graph into ● a quadratic both the functions, to ● a Choose f of ( x ) the or Remember the sides form Determine inequality check point If x-values this in the in it inequality, or f of ( x ) the < of region this satises region or solve ● Rearrange graph. of both or think in quadratic ( x ) Factor ● Place > the inequality inequality algebraically: so that either f ( x ) < 0 0. the quadratic satises these dividing ● the inequality, the f a ● algebraically: you satisfy To and nd its zeros. function. point the rearrange and the solution test 0 intersection zeros your and inequality. 0 points nd inequality, the > graphically: Select it an the it inequality inequality. the x-values several x-value substitute then two into into is in true, solution. If one the a of number the original then the on line, intervals. that intervals and inequality. interval inequality is is false, If the part of then it isnot. To solve ● Graph ● Select and non-linear the a region point If the where the Mixed Solve the the point is not on values point is is not not in by into is (e.g. ● Repeat To check ● Choose for all intervals. your solution algebraically: curve original true, (e.g. variables: equality. the is true, two the the inequality the inequality where 1 If dened that substitute inequality. region inequalities shade inside shade the the outside the the curve). region the a point inequality, inequality. If x-values this in it in the and region test this satises region you think point the in inequality, satisfy the satises the then the inequality. curve). practice each answers or inequality accurate graphically, to 3 giving exact 4 A rectangular of s.f. 100 m is playing to have eld an with area of a no perimeter more than 2 500m (x + 2) > 1 b x − 3x d 2x − 1 ≥ −11x −2 x + 15 < 3x possible 5 − 3 > 4, x ≠ 0 + 1 < 3x the playing eld. + 1 A tourist agency’s prots P (in dollars) 2x f < − 1, x x of 2 − 3x 5 2 e maximum + 4 length 2 2 c the 2 2 a Determine 5 ≠ 5 can be modelled by thefunction x 2 ( x ) = P 2 Shade the region representing the graph of −25 x number inequality. Check you have shaded the using a test 2 y > x of tourists. where Determine how x is the many are needed for the agency’s prot to be point. at a − 3000 , correct tourists region + 1000 x each least $5000. 2 − 4 x + 2 b y ≥ −2 x + 6x Problem solving 2 c y < 2x − 8x − 3 d y < log ( x + 1) 6 ( e y ≥ x 2) x e + 5 f Orange cans. y > x Solve algebraically and To conrm + 5x c 2x + − 6 < 0 b x sold in down, 2-liter the cylindrical surface must be less than 1000 cm area of Determine graphically. d (x − 10 x 2 x − 24 > cans, 0 values for − 4 x + 3) < 25 7 A packing at < 7x f 5x − 13 x ≥ 3 3x > 0, x + 5 1 the radius and height of the d.p. least company 600 cubic designs inches. boxes with Squares are a volume cut from −6 the g to 2 2 2x accurate 2 ≤ 35 of x be 2 can possible x x to costs 2 2 a e is keep + 4 a 3 juice 2 ≠ −5 of a 20 inch by 25 inch rectangle of 5 h > 4, x x corners ≠1 cardboard, and the aps are folded up to make an 1 open box. should be Determine cut from the the size of the cardboard, E14.1 A world of dierence squares accurate to 2 97 that 3 s.f. Review 1 A small in context satellite dish has a parabolic cross-section. 2 A parabolic microphone uses a parabolic ATL Its diameter is 30 cm and it is 15 cm deep. reector onto a Sketch b When the parabola on the coordinate a decide where receivesa is region place the a inside the State its dish, receiver number inequality wherethesignals strongest. satellite maximum Determine the to the cross are of that so that of a Draw signals. b The be which How you have Statement Modelling 2 9 8 of cm a the a to of the state On its your needs statement of inquiry? Give specic the equivalent forms E14 Models of a waves maximum depth this of 20 cm. information. representation can improve be placed that in the cross-section. mathematical describes model this region and domain. graph check your from examples. decision a, shade solution. Inquiry: with to parabola’s discuss the sound has maximum represent microphone (inequality) domain. explored focus cross-section and graph Determine and and 50 interior c Reect Its then it represents to receiver. and engineers section, likely collect axes. width designing to making. the region in b, Branching E15.1 Global context: Objectives ● Drawing tree out Identities Inquiry diagrams to represent conditional and relationships questions ● What ● How is conditional probability? F probabilities ● Calculating diagrams, Venn Determining probabilities diagrams whether two and from two-way events are tree can you probability tables ● C independent In which What a ways probability ● represent on be aects tree can conditional diagram? conditional represented? the decisions we make? D ATL Communication Understand and use mathematical notation 4 4 15 1 E15 1 Statement of Inquiry: Understanding resultfrom health using and logical making healthier representations choices and systems. 2 9 9 CIGOL ● conditional Y ou ● should draw tree already diagrams know 1 how Caesar ’s the He new 1980s Draw a playlist and selects choosing a to: eight two the songs songs same tree contains at from songs the random, song diagram ten from 1990s. without twice. to represent this situation. b Find the both ● use the addition multiplication and 2 You probability from have a the that the two songs are 1980s. standard deck of 52 playing cards. rules a You take one you take that card. What either a is red the probability card or a face card? b You take one card, another. What take c You a 5 without one calculate of probabilities mutually 3 exclusive A box 15 events a use Venn set diagrams and 4 notation A be There 7 5 card? then take a are a 12 take is 5 soft-center from event ‘pick 33 a the a another, the followed by chocolates One center ’ and taking copy of of taking Ar t both subjects. 3 0 0 E15 Systems let are Represent diagram. the Venn this diagram below question. the par t B of the Venn diagram that represents: B A is and Biology. There U d and chocolate center ’ . A a a box. hard soft students taking a Venn par t Shade take you P(A ∪ B ) with each face then that P(A). students Make you event ‘pick students this a and chocolates. random the the Find 28 at be Find b ● contains picked B that and card? hard-center Let by card it, probability replacement. What probability ● replace the followed take face is b ′ e B′ ( A ∩ B )′ c A ∩ B for S TAT I S T I C S Conditional F ● What ● How is Exploration The probability you that it will rain Amanda the that she 1 A be Copy the and conditional probability on a tree diagram? 1 that Let probability? represent theprobability probability P R O B A B I L I T Y probability conditional can A N D event plays ‘rains complete tomorrow plays tennis tennis is tomorrow’ this tree is is 0.25. 0.1. If If it it rains tomorrow, doesn’t rain tomorrow, 0.9. and diagram B be for 0.1 the the event events ‘plays A B P (A ∩ B) B P (A ∩ B B P (Aʹ ∩ B) B P (Aʹ ∩ B and tennis’. 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B ) to: P( B | A) = ATL P ( A) The You conditional can From use MYP Theorem For any 1 A A and can and B The theorem use B are outcome of in A and the Let A B A as other. B ) = rule B, a P ( A) + P ( B ) - P ( A ∩ test events if for B ) P ( A) × P ( B ) independent events. . outcome using axiomatic = then the this B ) is: P (A ∩ events, Writing probability recall: is: and 2 probabilities. of one probability does not notation aect gives independent that that a events particular Minnie misses probability that probability misses a Draw b Find P( c Find P(B ). d Show tree that her system. then that to train her she the dentist diagram P (B | A) = P (B | A′) . is late dentist misses train is is . If the appointment her dentist late and train is . is If late, the appointment let B be the the train is is . probability appointment. represent this situation. ). the appointment Theorem train are being not late and independent Minnie events missing using i her dentist Theorem 2 and 3. 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Your name back girl. of ‘a boys boy in a box put Let that eat that the a in B in a the be eats a two in rst the teacher hat. hat. the will are selects When Let event is and drawn an even breakfast. exercise likelihood healthy drawn box, token selected healthy he the and back number breakfast, event and not is not likelihood healthy the it girls everyone’s selected the 60% the 6 A be that the girl. are the statistics, eat class: putting drawn, that breakfast, your person to is Let event that that he If a is at random. second number number. a day boy is exercises breakfast’. Let B eats 90%. be falls the ‘exercises’. Problem 8 whether after is selected selected. be doesn’t event name the rst in random numbered ahealthy he at that According If students person the token determine person’s Tokens After 7 8, answer. students second 6 5 your Blood is solving classied in a variety of ways. It may or may not contain Bantibodies. Its rhesus status can be positive The likelihood of someone The likelihood of being Rh+ The likelihood of being B + Let X be 3 0 4 the event ‘having (Rh +) having is B antibodies B is antibodies antibodies’. E15 Systems negative (Rh ). 85%. 80%. (having B or Let Y and be being the Rh +) event is ‘being 68%. Rh+’. 4. the hole. The modied Optimist’s Creed day upon S TAT I S T I C S C Representing ● The In In Venn this The diagram scenario, sample This which is it space can represents is is represented ways taken in the conditional two that reduced conditional to Venn A events, has the and already elements diagram at B. be Find represented? the probability The shading region of on B represents ‘B represents this event that given is the A. A B right 3 in Here, A, or the A ∩ darker B , A shading B region. 4 numberofelementsinA ∩ P (B | A) B n (A ∩ a Venn sample diagram space Example In a group to can given 5 = 7 n ( A) calculate conditional probability by reducing the condition. 2 of 30 chocolate, 6do a Draw Venn b Given a you the 3 3 B ) = = numberofelementsin A In 5 A also A’. P (B | A). occurred. of 4 bythe P R O B A B I L I T Y probabilities probability A A N D that girls, not 12 like girls diagram she likes like milk chocolate. to nd One the chocolate, chocolate, girl is probability nd the 15 like selected the at girl probability dark random. likes she chocolate. likes milk chocolate. c Find the milk d Test whether using Let x probability that she likes dark chocolate, given that she likes chocolate. be i liking Theorem girls who 2, milk and like and ii both dark chocolate Theorem milk and are independent events by 3. dark chocolate. Draw Use 24 = 12 24 = 27 x = 3 + M 15 a Venn diagram. Theorem 1 to nd n . x x D D 9 3 is the event ‘likes dark chocolate’. 12 M is the event ‘likes milk chocolate’. 6 Continued on next page E15.1 Branching out 3 0 5 a P ( likes chocolate) b P (M | likes = Reduce chocolate) = given the M 6 the sample condition people space (likes who do to only the chocolate). not like Ignore chocolate. D 9 3 12 6 c P (D | M ) = Reduce M the sample space to M. D 9 3 12 6 d i M and D are independent , events ATL M and D are P (D | M ) = P (D | M ) = P (D | M ) Practice and only if : independent P (D | M ′) , = therefore events if they and are only not independent From if : P (D) P (D | M ′) P (D | M ′) = , P (D), therefore they are not independent events. 2 a 2 the a eld kayaking, 32 Venn diagram at the P (B | A) On b trip, 50 caving, students caving, and chose 4 a Represent b Find the students neither this 26 chose kayaking ii chose caving, iii chose caving iv chose kayaking, given a on they that E15 Systems a chose activity. Venn student that given do both. students neither information that to or they diagram. picked chose at random: kayaking chose B 15 nd: P (A | B ) choose chose probability right, activity, kayaking, students i 3 0 6 Theorem 2. Using Theorem 3. events. A 1 Using , , ii if caving. 11 21 S TAT I S T I C S 3 In a and group 8 of study a Represent b Find the A this Art ii studies Drama, iii studies either iv studies both group of and 25 a does not sing b does not dance c sings, The Venn Drama a on a Venn student that Drama 5 or Art, 15 study Drama, the diagram. picked student at random: studies Art Art and that are in students Determine Problem that given students given study Art, given the student studies either Art. dance, atrandom. students information studies or 12 the the a show. do not sing probability student Of does these, or dance. that, not 10 in the of A the students student show, the is sing, selected student: dance. solving diagram shows 35 students’ homework subjects. Ar t a Find the P R O B A B I L I T Y subject. i 6sing 5 students, probability Drama 4 30 neither A N D probability that a student selected at random (A) 5 i Art ii Biology iii Chemistry Biology (B) had: 2 4 homework 7 homework 7 1 b Find: i c Chemistr y P (A | B ) ii Determine the homework in Exploration In 42 homework. the rst probability all were three that given of asked a to European Cup predict 10 ● 6 ● 15 females predicted Italy ● 11 females predicted Spain males 1 Represent 2 A student was predicted predicted this was student subjects, ● males a iii picked that the P (C | A′) at random student had had homework. 2 semi-nal students P (B | C ) (C) the tournament, Italy play Spain. winner. Italy Spain information selected at in a two-way random. Find table. the probability that this student male. Continued on next page E15.1 Branching out 3 07 3 4 By altering the sample probability the student Find the probability predicted 5 space as you predicted that the did Italy, student in the given was Venn that female diagrams, the student given that nd was the the male. student Spain. Find: a P (M ) b P (F ) c P (S ) d P (I ) e g P (M | S ) h P (S | M ) i P (F | I ) j P (I | F ) k P (M | I ) l P (I | M ) In the M P (F | S ) f F I S 6 other shows how Male semi-nal, 42 predicted England (E ) (F) Total a Find the b Find: Reect Compare make a i the The Germany (G) 12 16 28 18 24 42 P(M probabilities about a table Total 14 that two-way winner. 8 student selected | E ) discuss statement the Germany. 6 probability and play students (M) Female England ii at P(M random is male. | G ) 2 for the which two semi-nals events, if any, are in Exploration dependent 2. and Hence which are independent. Practice 1 There male 3 are 28 players 18females a Use this participants and 12 are in a golf competition. professional female Of these, players. 5 are professional There are a total of playing. information to complete Male Professional the two-way (M) table. Female (F ) Total (P) Amateur(A) Total b Use i c the table to P (M | P ) Hence, calculate ii using a the following P (M | A) theorem, determine professional are independent 3 0 8 E15 Systems probabilities: iii P (M whether events. = Male P (S | F ) ) being male and being a = = = Female Italy Spain S TAT I S T I C S 2 100 students andwhether Use not the were or results theevents asked not they below are to whether were on they the complete a were left- school or P R O B A B I L I T Y right-handed, soccer two-way A N D team. table and decide whether or independent. 4 ● P (left-handed) = 10 3 ● P (left-handed and not on the soccer team) = 10 9 ● P (right-handed and not on the soccer team) = 20 Problem 3 From of the gender solving table, determine (male Justifyyour or Male Female Making ● What Objective iii. move You will D: need new the test test and 75 on of positive A negative Here are teacher use can test test Dr not kidney Total Other this is independent data came from. teacher 25 16 50 the dierent the table with decisions we probability make? forms and also of a mathematical tree diagram in representation order to solve the problem in 3 quickly 140 kidney Does teacher where 8 detect patients. do She kidney knows disease. that 65 of Dr Julia them Statham have performs kidney disease not. result result indicates indicates Statham’s kidney no disease disease. kidney disease. results: Positive Has science 3. them A a school Communication Exploration A the decisions aects between Exploration being in answer. Science D if female) test result Negative test result Total 30 35 65 15 60 75 45 95 140 have disease Continued on next page E15.1 Branching out 3 0 9 Let T Let D 1 A be the event the patient a The be event is is b disease kidney disease. 2 the Use 3 use Construct the 4 5 the not For or this the After and it gives Statham in a the to disease’. P (D) positive result will positive’. Calculate: c negative for use table the and decide d result for people test if your whether tree diagram doctor in that your should problem, tree which diagram? having an claimed it Patient data Using did this on represents tree use the 2 was T is the eye have this for an the diagram eye caused for same to accurate. of doctor information conrm do you by as whether prefer: this condition, the your is the table eye condition. the table, The sight lost table Did his sight shows not lose 25 225 75 675 determine whether the the sight patient’s claim answer. of the represents ‘plays operation in a tree representation validity diagram event in patient operation. diagram and use it to determine if the justied. which the eye a the operation information claim Determine Venn the information Represent The the have test. representation treatment Justify illustrates ATL had not the valid. patient’s c 90% not with not Explain. operation that Patient b is do knowledge or Lost is people who 4 hospital’s a P (D ′) test. information the Practice 1 a kidney random. probability the has is table. Use or Dr if a information conditional should and at result P (T ′) successful kidney test ‘patient selected P (T ) test ‘patient tennis’ (the patient’s 65 and table claim. members G is the of or the Give a event tree sports ‘plays T diagram) evidence for best your decision. club. golf ’. G If 30 10 Represent b Use all golf are c three information in representations independent Explain, 310 this with a to two-way table. determine if playing tennis and playing events. reasons, which E15 Systems are using tree diagram, and T ′ pair of a put T 15 10 a you representation was the easiest to work with. on the rst branches. S TAT I S T I C S Problem 3 The L is tree the A N D P R O B A B I L I T Y solving diagram event shows ‘studies information Law’ and E is about the 100 event students ‘studies at a university. Economics’. L 0.8 E 0.4 0.2 L L 0.4 0.6 E 0.6 L a b Use the tree i P (E ) v P( E diagram ii ∩ L ′) Determine whether ● Can ● How do Practice 1 The use cafeteria had From b Hence, d Verify e Using 2 70 b What are 2 the L) vii Law or probabilities. P (L | E′) P( E ′ ∩ studying diagram diagram waes one 10 to is iv L ′) viii Economics represent most at any useful morning morning. students and 4, Of had using is a iii table results use who that ) 2 to are and P( E ∩ L) P (L) are for situation? a given situation? break. these, 33 There students were had apples (A), neither. Theorem a the the 1, draw a Venn diagram. represent the same 3, ) the for test iv P (W | A) v P (W | A′) information. each form whether of representation. having waes and having events. most worked their P (A | W Theorem independent about worked Using and P (W two-way worked Given and cafeteria (W), ii students a apples Theorem questions rest iii following 3 which information, that In surveyed studying the calculate: a apples The the P (A) Make c in the c ∩ probability decide sells waes a i nd 5 51students 18 P( E ′ discuss any you you events. and you help P (L | E ) vi independent Reect to in work. appropriate the 12 representation holidays, boys and 30 28 of whom girls to are worked solve boys, the problem. were full-time. part-time. student worked probability that part-time, a person what is chosen the at probability random is she male is female? and full-time? theorem ‘working as part-time’ a justication, are determine independent whether ‘being male’ and events. E15.1 Branching out 31 1 3 The and probability 95% if it Gregoire clear. The arriving Calculate the probability of b Calculate the probability that c Determine Out of There 150 whether are the 30 are left-handed a Find P (F | L). b Find P (L | F ). c Determine whether independent. it is of events is 60% if there is fog, at school that school on time. Gregoire on time’ arrives and ‘a late. clear answer. (L) are ‘being time 20%. given to your who is on arriving ‘getting left-handed Justifyyour fog clear, Justify students the school Gregoire events independent. students, are14 at probability a morning’ 4 is of and 80 female male’ are (F and male (M ). ). ‘being left-handed’ are answer. Summary In mathematical probability condition of B of A given B notation, occurring has P (B | A) given occurred’, or is ‘the that ‘the If A A and B conditional probability events, then B are does independent not If this formula the events outcome if the of outcome the other. A and 3 B P (B | A) use aect axiom: P (B | A) can independent probability Theorem You are A’. one The and the to calculate are = independent events then: P (B | A′) conditional probabilities. You as a can test for Mixed 1 A lab at 2 are random type to 45 B. rule) events. check for Find the probability have the same the probability A, tree type Two b type multiplication samples are Draw Find a blood these, a c (the independent 100 Of 15 Theorem practice has tested. and use samples to are are represent that blood that need 40 to be type to be 2 the rst From the Venn diagram Find not the a P (A) b P( A ∩ B ) c P (A | B ) d P (B | A) e P (B ) f P (A | B ′) g P (B | A′) this. two samples group. that the type 312 probability O, given nd: drawn the rst second one was sample type is A B B. 20 d below, A contamination. diagram given that O, that that the the second rst E15 Systems sample onewas. 10 15 is 20 of S TAT I S T I C S 3 The probability that it will be sunny tomorrow 6 4 is . If it is sunny, the probability that In a netball court: 8 There are match have there brown A N D are hair 14 and P R O B A B I L I T Y players 6 have on blue the eyes. the 5 4 students whohave neither brown 2 cafeteria will sell ice creams is . If it is not hair nor blue eyes. Let H be the event ‘has 3 brown sunny, the probability that the cafeteria will hair’ and B be the event ‘has blue eyes’. sell 1 ice creamsis a Draw a Venn b Determine diagram to represent this. 3 a Represent this information in a tree diagram. these mathematical b Find the c probability Determine of 4 the cafeteria S is ice the event It is P (S will if the creams event ‘it is = ‘Tim ice sun it will sunny shining and wearing the selling i P (H ) iii P (H shorts’ and R is v P ( H ′) vii P (H ∪ B ′) ix P (H ∪ B )′ that P (R) = 0.5, P (S | R) = 0.2, Represent b Use both c Hence this situation in a tree Theorem events is related S trying as to iv P (H vi P ( B ′) ∩ B ) viii P( H ∩ B ′) 2 and and to being liking 70students, 30 T are Theorem not determine 180 cm or basketball. of which if all the correct conditional mathematical probabilities, notation. 3 to A survey was carried out regarding the school verify code. The two-way table shows the results: independent. being more) She were state the diagram. dress dened B ) and 0.8. a Sahar ∪ P (B ) the 7 5 ii events. using that correct and creams. independent is be using raining’. known | R′) are that sell probabilities notation: is tall Should (here have somehow 180 have code surveyed over Should dress not Total dress code cm. Middle 48 students surveyed like basketball, 29 30 of 45 school whichwere under 180 cm. High a Draw a two-way table to represent 40 this. school b Find P(tall). c Find P(not d Are Total the tall events basketball’ | likes ‘being 55 110 basketball). tall’ independent? and a Copy b Use and complete the table. ‘liking Justify Theorems 2 and 3 to determine whether your type of school and wanting a dress code are answer. independent Review in 1 shows The 200 table events. context the occurrence of diabetes in a From the table nd: people. Diabetes Not overweight No 10 35 Let D be the event ‘has diabetes’. Let N be the event ‘not overweight’. P (D) iii P (D | N ) ii P (N ) iv P (D | N ′) 90 b Overweight i diabetes 65 Determine being whether overweight having are diabetes independent E15.1 Branching out and not events. 3 13 2 The has a probability a test bone for disorder this condition not there Let B that is randomly is 0.01. condition there, (a a false and is The selected probability positive 0.05 if person the is 0.98 if 4 that survey is positive). cancer. Of survey, 981 lifetime. were be be the a Draw the event event ‘test ‘has is the bone disorder’ and of tree to a represent cancer at who some in the smoking non-smokers smokers people at the battled in point and the in survey, their there cancer. T positive’. diagram the looked cigarette 125 000 had Of 1763 people between the Find the selected a 200 000 relationship the condition A probability from the that study an individual who battled cancer these was a smoker. probabilities. b b Calculate the probability of success for Find the cancer test. Note positive the for negative test is people for successful with people the if it the and c disorder. Let the a 3 Michele is making drinks to sell at the She makes a ‘Super green B be the event former event ‘being not baby grapes a with ‘Triple milk, spinach, a cucumber, caloric chocolate chocolate content milkshake’ a caloric syrup and content of kiwi 140 with 370 kcals, and d kcal Does records the number of MYP your people two buying each product. 26 super green cancer’ and (includes Demonstrate A be being are whether independent. and MYP smoothies answer mathematically. in c choosing encourage to smoke? or discourage Explain The following information was extracted from a cup. cancer website. DP 1: About 69% of skin cancers are students associated purchase ‘having smoker’ events answer from Statement students had ice-cream per skin She who and chocolate chocolate of someone smoothie’ apple, 5 with a smoker). these Justifyyour with that smoked. school or play. never tests disorder without probability the and 48 with exposure to indoor tanning triple machines. chocolate 13super milk milk green shakes. DP smoothies students and 24 purchase triple chocolate Statement people shakes. atotal Determine, using whether age the independent two-way to table Reect both of the their to and theorem student choice answer of this 2 and (MYP drink. theorem vs DP) Use have you Give specic In year a are United treated population Statement tanning of 330 States, for skin 3.3 million cancer out of million. 3: 10 million US adults use indoor machines. question. Let A Let B be be the the event event ‘developing ‘exposure to skin cancer’. indoor tanning’. discuss explored the statement of inquiry? Write down probability statements 1, 2 and 3 in notation. examples. b Determine cancer and whether exposure independent Statement of Inquiry: Understanding health and making healthier choices result from using logical representations and systems. 31 4 the 3, is a How a 2: E15 Systems events. developing to indoor skin tanning are Practice Answers 1 a 5 4112 b 114 333 5 c 340 030 5 5 E1.1 2 Y ou 1 a c 2 a c should already 11 204 know b 2996 1161 d 999 538 Fifty b Five hundred d Five tenths Five Practice how × 1 2 3 4 5 10 1 1 2 3 4 5 10 2 2 4 10 12 14 20 3 3 10 13 20 23 30 4 4 12 20 24 32 40 5 5 14 23 32 41 50 10 10 20 30 40 50 100 to: thousand 1 1 a 23 b 25 c 109 2 a 191 b 226 c 107 a b 4533 112 024 6 3 1215 = 6 299 6 d 92 3 1011 4 a e = 31 3 , 52 100 011 10 Every f = 35 2 digit has , 1010 10 moved one = 68 , 1111 10 to the = b has been lost. So the number 10 × 23 10 = 21 10 × 35 6 6 156 5 right, and Mixed 10 the has practice nal 1 zero 13 70 4 place = a 13 b 54 c 69 halved. d 52 e 135 f g 14 559 h 2418 i a 1 100 100 e 1 101 100 2387 107 10 Practice 2 2 b 10 201 2 c a 1 111 100 111 b 1 101 000 d 12 444 2 3 33 213 4 i j a 472 = 314 8 b 472 10 = a a 223 = 63 5 c = 214 = 82 1741 8868 = = = 2468 a b c c, 6542 b is at 1011 a = = = h b = 48 b 25.25° e = a 10 110 e 22 211 45 2 = 9 231 10 the 3BEE 16 7, = 6 largest the and d 12″ 58.205° c 10 001 111 2193 1EADB j 10 000 h 1081 3 1 011 323 4 1BA8 12 d 2 g 4 k 12 11A 12 16 16 written because c 31 2 20 010 base, because his number 5 was a 10 110 b 11 110 2 d out. = e contains a 1111 2 2120 3 number c 2 2101 f 34 535 4 34 535 h 6 29B1 6 7, 2° f 1 001 010 f l g = c 62.5083° b i 4 3464 when 9 3 8 used 90° 2 1725 i 3FFE 12 16 6. a 11:20 b 13:15 c 14:25 9 d e 42° 6 1319 10 101 101 3 4 15 10 = 4 22 222 022 = 11 110 213 d least 8, l 16 2 6 d 419 12 100 011 001 2 f 10 a, = 8 = 1844 smallest b, 281 10 d 67 10 = = 2 = 10 Donatello the 1 010 010 55 9 4 k 12 5 431 8 10 110 111 9 i b 7 2 g 120 10 6 e 320 12 2224 8 d 3 11 111 111 h 2 1A7 5 3 2 g 5 B89 d 4 230 122 12 c 1210 3 f 3 1 20 136 09:26 e 03:55 729 10 7 a 1100 b 100 001 2 d Practice a 210 = 300 12 c b 301 10 BAA = e = 1714 d G0 10 10 = 30 a 190 = c b b 10 c 47 806 = BABE d g 16 g, 4 2313 g, = 4 g, = ACE f = 64 206 16 BEEF d a The possible = codes 256 run from 00 g. + weight system 231 232 1 g, 4 = is equivalent to counting in base 4. 1 223 111 4 g, 16 × 12 g, 3 × 64 4 g, 2 × 256 g, 2 × 1024 g, 1 × 4096 g 16 to FF , or 0 16 10 to 255 1330 4 , = 23 220 4 4 10 2 are 1 4 FACE 10 16 sothere the 331 213 16 e 3 g, 10 Because 10 CAFE 10 1 183 16 48 879 16 51 966 = 10 10 e 2766 16 5 320 20 BE 10 4244 5 4 2 f 769 16 12 a 1 000 001 2 432 3 3 8 1 c 2 121 121 × 4 g, 2 × 16 g, 3 × 64 g, 2 × 256 g codes. 10 b 16 = 1 099 511 627 766 (Roughly 1.1 trillion) 9 a It might ve Practice 4 be times between b 540 = thought the the a 445 2 a 222 b 360 b 144 8 c 2003 c 425 8 cent a 6 137 b c 6 1554 8 732 c 11 717 b Since 216 8 = 1441 165 8 = could be was worth relationship highly confusing. 5 10 12 + dollar dollar the 5 1441 = 3421 5 5 BA99 12 5 the 9 5 a the that redening notes. 10 412 10 8670 7 eight = 10412 4 and but so 8 246 3 coin, idea 5 Hence 6 largest good 4130 10 1 a 403 , 8 So 216 8 165 8 = 31 d It ten notes. would require a lot of notes to pay amounts that were 8 close to the next bill, such as $990. Answers 31 5 Review 1 a 2, 3, in 5, context 7, Practice 11 1 a 2 A B C g f b 13, 17, 19, 23, 29, 31, 37, 41, 43, 47 1 c 10, 11, 101, 11 101, 2 “ ” a 11 111, represents 1, 4, 111, 9, 16, 1; 1011, 1101, 100 101, no 25; 101 001, number the 10 001, starts square 10 011, 101 011, with a = | — — | — —, 49 = 101 111 leading 1, 1, 2, = 3, 4, 8, 13, 21; | — — — | —, 55 the = , 64 = 1, 3, 729 3 a = 27, | 81; | | 16487.5… b c 9, 659.5… Fibonacci | | | | |, Jupiter: Saturn: powers | | — — , 6 A 89 = of 2187 3; = 243 = 2, {1, 2, 2, 3}, B | 13}, C = { 2, 2, 6} = Domain of g is f A. Range of g is f C. | | — — a h g | | | | — —| |, | — — — | — — — | 0 2 1 5 1 5 2 4 3 | | days Domain 10 100 010 011 111 of h is g {1, 2, 4}; range of h is g { 1, 3, 5}. 101 101 110 110 010 f h 1 010 100 101 011 000 Neptune: 10 110 000 010 111 010 A Venus days 9, numbers; b day {5, days Uranus: e = 6 hours 1 010 010 100 d the 2 13 | — — — — — — 2 c 9 3 numbers; | | — — — d 34 2 zero. c b 2 10 111, b 36 5 on per year is is longer less than than its year, so the number of 1. 1 2 3 3 5 4 4 7 6 Domain of f is h {2, 5, 7}; range of f h is {3, 4, 6}. E2.1 c g f Y ou should 1 already know how x to: a b x b c y c d z y 5 4 3 2 Domain 2 of g is f {b, c, d }; range of g f is {x, y, z}. 0 0 3 1 a 4.5, 8, 12.5 2 b 2 Domain is {6, 8, 10}; range is {4.5, 8, 12.5}. 3 4 2 a b c d Domain and Domain Domain is is Domain e Domain a f x x is Range ≥ ≠ x is 0, 0; ≠ 2 both Range 2; ≤ are Range is is Range x ≤ 2; y y is ≠ y a 0. ≠ Range (4) = 5 b f ( 1) = 0. is y ≥ 1 Domain −5 c f (3x) = 6x 2 + 5 0 3 9 4 5 13 8 Range of Practice 3 g f is { 2, 0, 4, 8}. 9 1 of k)(a) Domain h is domain , = of k is ; 1 of 2a h a is 2; domain domain , of k of is h + k is a 12 b e 1 f h)( x ) = −x 7 c 18 d 2.25 h 11 ; 36 g 6 k x 2 i 3 ( g 2 1 3 3 (h 3 0. 5 Practice 0 0. b 3 g f ≥ 3x 2 + 6 j 3x + 1 + 2 5 = l x + 2x + 2 + 5x x + 5; domain of ( g h) is 2 2 a x 5 1 3 Domain of h is domain ; of k is x ≥ ; 2 b (2x + 2 1) 5 + 1 = (4x 2 + 4x + 1) 4x + 4x 4 3 1 2 (h + k)( x ) = 2x − x + 3x + 1 ; domain of (h + k) is x 2 ≥ 3 a f ( x ) = x , Domain is , range is x ≥ 0 3 2 4 (k h)(c) = 2 − 3c − 2c + 5; domain of (k c) is c 2 ≤ 1 f b g (x ) = , x ≠ 1 3 1 5 ( g + h − k )( x ) = 6x − 8 + − x + 4 ; domain is x ≥ −4, x ≠ x 1 0; 4 5 2x 1 (k − h − g )( x ) = x + 4 − 5 − 6x + 8; domain is x ≥ −4, x ≠ 6 a b Domain Domain of of f is f + x g ≠ is 0; x domain ≠ 0, x ≠ of g is x ≠ 2. a 3.5 b e 2 f a x 6 represents commission 2 earns 7 Students’ own 2% answers b 7 316 Answers 2 c 0 d 0 f ( x ) 0. 2x x f = 1, g ( x ) 3 the 0 amount paid, on. g and g of sales 3.5 in the week; represents the commission is the she 3 Practice b 4 Domain of f is domain ; of g is x ≥ 1; f g (x ) = x − 1 ; 2 1 a b 15 cents; 210 g; 45 265 domain cents x c 33 cents. of f g is g ; f (x ) = x − 1; domain of g f is g An orange of radius 5.1 cm weights 250 ≥ 1 or x ≤ −1. g, 2 c and costs 33 Domain of f is domain ; of g is f ; g (x ) = 9x − 15 x + 6; cents. 2 d f g ( g ( x )) f (x ) = −3 x − 3x + 2; Both domains are 1 2 2 a 3 Time t (seconds) 0 1 2 3 4 0 2.5 5 7.5 10 p (q (t )) a = 4t − 15; domain is b q (r (t )) = − r (cm) ≠ 0 ; t ≠ ±2 1 4 Radius 4; t 2 t c p (r (t )) = + 1; t ≠ 0 r d (q (t )) = 2 t t b f (t) = 4 2.5t 4 a g ( f ( x )) b h ( g ( x )) 2 c g (r) πr = a 2 d A = g ( f (t)) = 2 πr π (2.5t) = 2 5 6.25π t = a g ( f ( a )) = 2 a v (t) = 10t 6 k 7 a = f v πr = h h b g ( ( g ( − b )) − 1 = 3 4 2 = f 3 v 2 b b + 1 3 −2b 2 ( g (x − 1)) = 4( x − 1) 2 − 3 = 4 x − 8x + 1 2 πr 2 f ( −3 x )) = 2 ( −6 x − 3) 10t c h v (t ) = 2 2 πr The height 8 of the water in the cylinder as a function f 2 (3 x − 1)) = 4 (3 x − 2) + 3 of 8 9 time g ( a 7 b 2 c t. 3 d t = 5π a r = 2t = 15.8 seconds 2 10 4 b Area a B ( T (t )) a as a function of the radius as a function of time. = 20 ( 4 t function of + the 2) − 80 ( 4 t amount of + 2 ) + 500 ; time food Bacteria is outside as the refrigerator. 2 c 5 a 45 289 cm b i Fuel cost is a ii Volume of a iii Volume of a iv Size function tank is circle a of vehicle function velocity. of is a function of a regular 11 time. of each angle a s c d a i = 1.5w = polygon is a number of sides of a f Interest earned is a g Students’ own 1.2w b d d $86.40 = 0.8s f = x 5 ( x ) = ii 0.75(x 5) g iv ( x ) f = 0.75x g ( x ) function of iii, the price is $33.75. From iv = the 0.75x price 5 is $32.50. time. dierence is $1.25. answers 13 Practice ( x ) From The b = polygon. b v 0.8(1.5w) function iii ofthe hrs. time. 12 of 3.8 For example: a (x ) 5 5 4 f = − x + 7; g ( x ) = x b + 1 f (x ) = x ; g (x ) = 4 − 3x 3 1 f ( x ) = x ; g ( x ) = 2x 1 3 2 c f (x ) = −5 x − 8; g (x ) = x f d (x ) = ; g (x ) = x − 4 3 2 f ( x ) = 3 f (x ) = f (x ) = 5 f (x ) = 6 f (x ) = 2x 1; g ( x ) = x x x 4 x ; g 6x (x ) − 5; = 6x g (x ) e − 5 = f (x ) = 10 ; g (x ) = x x Note: Other answers to Q13 are possible. 3 x ; g (x ) = 2x − 1 Review in context x 2 ; g (x ) = 3x − 2 1 a r (t) = 0.8t + 70 2 Mixed b practice A r (t ) = π (0.8t + 70 ) 1 a ( f + c ( f + g )( x ) = c 2 2 1 x − 9x + 2 b ( g d ( g − f )( x ) = x + x − 135.5 minutes or approximately 2 hours 2 4 5 2 −19 x h )( x ) + 6 4 x = − h )( x ) − 17 x − 2 2 a K (C (F )) ( F − 32 ) + = 4 4 b 373, 273 2 2 x e (h + k )( x ) − 2x − 8 = x ≠ 0 3 a r (v (t )) − h )( x ) + 40 + 3t 2x b − 8 = ; x ≠ 0.202 + t 0.1 = 500 2 − x (k 2 ; 4 x f 273 9 = liters per + 0.2 km 0 4 x 4 a f ( x ) = 4x + 6; g ( x ) = + 3 2 2 −5 x g ( f + k )( x ) + 2x − 2 = ; x ≠ 4 x 0 g ( x f ( x )) + = 6 + 3 =2x + 3 + 3 = 2 x + 6 2 1 2 a Domain of f is ; domain of g is x ; ≥ b Set the above expression equal to the friend’s result 2 mentally solve the equation. 1 f g (x ) = 2x − 1 + 1, domain of f g is x ≥ ; 2 5 Students’ own answers 1 g f (x ) = 2x + 1, domain of g f is x ≥ 2 Answers 317 and 1 1 E2.2 5 a f (x ) = ; f Y ou 1 a should Not a already function, since know b ∈A c ∈A does how c Not It is a a function, since has not two have its inverse is a function with domain x ≠ 1. inverse are symmetrical about the line y = x the line y = x to: an image in images in B, p b Domain a y of f is x ≠ 1. B 6 b and the 1 x and = ± x + 2 r f function. and its inverse are symmetrical about 1 2 a b Not It a is function, a since 2 is mapped to 1 and b 3. Domain a It is function. a It is is function. not a is x ≥ 2, (x ) f 2 + = x , x ≥ 0, or domain of x ≤ 2, f (x ) = 2 − x , x ≥ 0. 1 7 b f 1 f 3 of a f (x ) = x + 5 − 1 function. f and its inverse are symmetrical about the line y = x 2 4 a f g (x ) = 2x + 3 b g f = 4 x 1 b Domain of f is x ≥ −1 f for (x ) = x + 5 − 1; or domain of 2 (x ) + 4 x + 2 1 f Practice is x 1 ≤ −1 ± 8 a y for 2( x (x ) − 3) + = − x + 5 − 1 2 = 2 1 a Neither b Neither d Neither f c Onto, not one-to-one and its inverse are symmetrical about the 2( x line − 3) + y = x 2 1 e Onto, g Both not one-to-one f Onto, not one-to-on b Domain of f is x ≥ 1 for f (x ) , = x ≥ ≥ 3 3, or 2 h One-to-one, not onto − 2( x − 3) + 2 1 2 Students’ own domain functions of f is x ≤ 1, f (x ) = , x 2 Practice 2 9 Either f ( x ) = x for x ≥ 0, or f ( x ) = x for x ≤ 0. x, x 1 For f ( x ) = x, x ≥ 0, f 1 ( x ) = x; for f ( x ) = ≤ 0, f ( x ) = x 1 1 a f ( x ) = {(1, 3), (1, 1), (1, 3), (1, 1)}; not a function 1 b g ( x ) ( 1, = 3)}; {(4, is a 2), (3, 5), ( 3, 2), (1, 1), ( 4, 4), ( 2, 1), 10 a s ≥ b h 0, since h (s) never be less than 0. s 198 function. can 1 (s) = 1 c h ( x ) ( 1, = 1)}; {(0, not 0), a (4, 2), ( 4, 1), (2, 2), ( 3, 3), (4, 4), 0.9 function. The c 2 a The inverse is also a function. b The inverse is also a function. c The inverse is also a function. d The inverse is also a function. e The inverse is also a function. inverse Practice f The inverse 1 3 a y is not a 2( x ; also a function. 4 1 Yes 2 No 3 Yes 4 No 5 Yes 6 Yes 7 Yes 8 No, function. x = is 203 function b y = 4) − ; 4 f ( g ( x )) = x and g ( f ( x )) =| x function 3 1 c y = −5 − 3 x ; function y d = ; − x 1 x ≠ −1, function Mixed practice + 1 5x 1 e y = x ≠ , function y f = ± x − 1; not a function 1 a i Yes ii R = x b 3 g y y i Yes iii No ii S = 1), {(0, (3, 2), 2), (1, (4, 3), 3), (1, (5, 5), 4)} (7, iii 6), Yes (0, 0)} 3 = x ; 3 + i {(2, 1 function h y = x − 2; function 1 2x c ; = x ≠ 1, x No iii 2 Practice i ii T = {( 1, 0), (1, 3), ( 1, 4), (6, 3), ( 1, 3)} function 1 a No Neither b Both 3 c x + Both 2 1 1 a f (x ) = . The inverse is a function. 3 a No. f is not into. b Yes. d No. f is into and onto. 5 f and its inverse are symmetrical about the line y = c x No. f is not into (x ) = 1 2 a f (nor 8 (x ) = 2 (7 − x ) . The inverse is a function. onto) f is not into. x 1 4 i a f 3 f and its inverse are symmetrical about the line y = x f 1 3 a f (x ) =± x b + 3 and its inverse 4( x f and its inverse are symmetrical about the line y = are symmetrical about the line y = x symmetrical about the line y = x function + 1) 1 x ii a f (x ) = 3 1 b Domain of f is x ≥ 0, f (x ) = x + 3 , x ≥ −3 or domain of f 1 f is x ≤ 0, f b (x ) =− x + 3; x ≥ and its inverse are function −3 1 iii 4 a y f = ± and 1 − its a ( x ) =± f 4 − x x inverse are symmetrical about the line y = x f and its inverse are symmetrical 1 b Domain of f is x ≥ 0, f (x ) = 1 − 1 f is x ≤ 318 0, f (x ) = − 1 − x ; x Answers ≥ 1 x ; x ≥ 1, or domain of about the line 1 b For domain f ( x ) ≥ 0 f (x ) = 4 − x , x ≤ 4 y = x x + 2 Practice 1 iv ( x ) = f a 1 ± 3 f and its inverse are symmetrical about the line y = x 1 a 2 + 2 ii iii 4 x 4 i 3 2 2 1 b For domain f ( x ) ≥ 0 f (x ) , = x −2 ≥ 3 2 v a and its are symmetrical about the line y = 4 1 x. AD i 2 = DA 5 1 = 1 x 5 1 inverse b b vi 4 2x f 2 v ( x ) = f iv x 1 5 ≠ 2 1 1 x 1 5 a f ii (x ) = ; EG = = GE function 6 6 5 x 2 c 1 f b (x ) = ; The 3 d 1 f (x ) d g = (x ); + 2 = h (x ) = 3; (x ) = (x ) x + 3; − x if x ≥ −3 + 3 , if the e i 2 a C F the domain of f is x ≥ domain of f is x ≤ 3 a (5, 4 a MN to A but 5 opposite sign. iii 0 iv 2 0 0. 9) x 2 ≠ + G b E iii b (1, to C 3 8) D c A to c (0, D 3) 7 = 2 3x ii d H to d (14, B 0. ; = x PQ b 5) = 2 3 2 1 g (x ) ; = x 1 s h x ≠ 1 c RS = x − 3; x ≥ For each pair of Length 8 a = 39.5 functions f and g, f (g ( x )) = g ( f ( x )) = x 5 DC After = 4 2 = 4 cm 3 412; 7 0 7 TU d 1 = 2 (x ) 4 1 6 size, 5 1 p same ii 1 f the function 1 h 3 2 5x 1 e 1 function 1 ( x ) have 1 i 1 c components function 6 24 months, a computer has depreciated from 6 b 1 $700 b 54.2 to to $412. months; it depreciate takes from 700 54.2 $700 d for a computer’s value 7 E.g. (0, 0) and ( 5, 3); (3, 1) and ( 2, 4); (6, 11) and (1, 14) $50. Practice d (t ) 2 1 1 c months to (t ) = ; d (t) is the number of months for a 12 computer d depreciate to t = is −500, which means 1 a 25 b 2 a 5 b 3 a 6.40 b 4 a 6 5 a 9.06 7 Any Add 8 in to subtract that after 100 months the 10 c 2 8.25 c b 26 b 3.16 10 5 d 5 4.47 d c 25 c 13.3 2 e 13 f 281 13.2 e 8.94 f 12.5 d 1 e 10 f 5 d 6.80 e 20.8 f 21.0 computer context 34, 5, multiply to get the this result answer by 2, divide then by 6, 2( x The result is the original four from (8, 1), (8, 5), (9, 0), (9, 4), (4, 1), (4, 5), 9. (3, a c worthless. Review 2 5 d (t). 16.7 e 1 to number, + 0), (3, 4) 6 ) − 12 = since x 8 x = 2, y = 1 9 x = 2 2 b Choose a number, multiply by 2, add 12, divide the result Practice by 2, and then subtract 6. The x 2 3 f (x ) = 2x result is the 3 for 1 f (x ) , = x ≥ 3; The puzzle would not 1 real Students’ 5 numbers less than own answers 2 a AB AB 1 already know how x = 0, 3 94.1° y 7.28 = 6 (3 s.f.) b e 5 1 7 5 BA = 1 1 AB 11 = BA 11 = 5 2 0 0 = 7 = = to: c 53 d BA a 5 17 = b should 1 3. E3.1 1 c Y ou b a 4 8 1 + 3; 2 work 3 number. 10 10 1 d AB 9 BA AB 9 = BA 7 = 0 e 9 = 0 9 = 7 Answers 319 4 3 ( 4 a 15, 4) a = 0, b = −1 b a = 1, b = −2 c a = 3, b = 6 3 2 7 a = −1 2 b = 8 3 OM 10.5 a 87° b 5.5 6 6 a = 17 and CD = 2 17 . They are dierent = DC = 10u ABCD or 12 b 4 37° 5 m = 6 a ab b It 5 127° b 67° c 25° a + (a is + an = Any 5 d 2)(2 b) equation b 25 9 15 the 10 a = −1 or odd 11 b = −3 13 a AB b OB = c AC = a = 0, in so two a b = one out. = 4 parallel OC to because OC = 2 AB OA + AB = b + a = a + b unknowns. AO + OC = 2a b = non-zero OC is −2 multiple 1 d 2 b X lies OX hence e = Since on OB, OX is parallel to OB , of Since X k OB = lies on = k(a AC, + AX b). is parallel to AC , 14.5° 3 hence AX = m AC 8 So LHS = RHS = OX = OB k (a + b) = b 6 m = , k = a 2 a b u 3 a r + v b v w c u + v + b b a c b a d b 2a e a + 5q = 3t m(2a b) , so ratio is 1 : 2 in context a 76 cm b 45 cm c 67 cm 4p d s + b) b 2 = b w Review a = AX m(2a 3 3 1 + 2 1 Practice + 16 f 4 2 10 15 and 6 35° 4 9 4 3 , a 45 4 8 36 111° 2 7 20 8 1 c 16 and 18 is a and 3 30 ABDE Practice 1 9 + 5v 7 97° lengths. AB c and 20 AB 84° 8 b 3 = 4 5 c 4 1 3 5 Practice 5 b a 95 cm e 292 cm f 447 cm 2u 2 3 a 15 m 3 5 a + b a 2 c A rectangle with sides in the ratio 2 : 60 3 c Mixed 25 b 250 + 600 1 5 + 650 = 1500 657 cm = 15 m practice 2 3 11 4 a AE b c 3 , 55 d 4 = a 36 19 4 b 2 a AB 3 = BA 3 OF b AB BA = 3 7 AC c AB , CF = 510 cm 45 , | AC | = 2169 = 3 241 3 3 BA 24 = = = CF 45 24 3 12 = CE , 3 c 30 = 3 7 22 = = , | CE | 676 = 20 = 5 5 AC is longer 2 d AB 13 = BA 13 d Perimeter a PQ 14 3 9 3 3 b a c area 18.6 m 6 2 32 d 5 24 = 3 m, = 14 5 18.2 15 PS 60 = 45 4 a c a a = 0, b = 1 b a = 2, = 5, b = −4 d a = −2, b = b −3 = 4 c SR a 29 b 5 c 3 41 d 5 30 Answers hence not parallel 17 opposite 320 , 5 25 = sides not parallel. to IQ. Not rectangular, 6 a OU 18 = b UV is 25 c VW VW | to WX so 47 , WX is a µ) ∑ f (x µ σ 10 50 20 123 39 20 5 2 41.2 6.15 2.06 197 80.34 5.05 2.06 43 223 102.34 5.186 2.38 23 115 39.56 5 1.72 trapezium. , VW = UV 0, VW XW = 0 25 = 25 2 , UV | = 22 2. | XW | = 47 2 2 Area e ∑ f x 47 UVWX ∑ f 3 = 22 = d = parallel 2 22 so UV , 22 = 17.25 m 45˚ 2 Length (cm) 4 mid-value f xf 2.5 3 7.5 11.4 389.88 7.5 4 30 6.4 163.84 12.5 6 75 17.5 7 122.5 3.6 90.72 22.5 5 112.5 8.6 369.8 E4.1 0 Y ou should already know how 5 to: < < 10 1 a 3.9 2 a A b b population A sample Practice is is the any whole subset of x x < ≤ ≤ x 5 10 ≤ 15 ( x ) µ x µ) f (x 11.76 1.4 80.5 of all the outcomes in question. 15 < x ≤ 20 20 < x ≤ 25 population. 1 ∑ xf = 2 25 µ) ∑ xf (x 347.5 1 a µ 5, σ = = 2.19. Mean is 5, but on average the spread of the The data b µ is ±2.19 = 16.54, σ This c µ of each that the = 15 cm, σ the data = is mean ±3.07 is 16.54, on each but on average implies of 13.9 and the standard deviation is 6.41. Practice that the 3 2.05 cm. the mean is 15 cm, but on average µ = 11 kg , σ data is ±2.05 cm on each = 1.5, kg. Fully grown mute swans will on the average spread is the side. 1 This mean side. = 3.07. implies spread on weigh between 9.5 and 12.5 kg. side. 2 d µ = kg, σ 40.8 This implies spread of = 4.75 that the kg. the data is 2 mean ±4.75 is 40.8 kg on kg, each but on average the a ∑ x µ b side. c = = 27 m, 1.811 There is not standard 2 a µ b This = min, σ 25.4 = 2.82 buton that average the the mean spread length length of of journey journey is 25.4 a µ motorway: = 19.8 min, σ = 4.57 µ lanes: = 20 ±2.82 mins. 3 You min, σ = 1.41 i the in country the lanes, country m dramatic deviation has change in the mean, however the changed. because lanes there the is of the team should lie within 6.7 cm of the mean. would 1420 expect mm, the rainfall to be within the range of so: 1100 two less mm is exceptional min b b 48.628 0.067 min a country a = min, 1109 3 = σ min. 68% implies ∑ x m, means are equal deviation 1400 mm is not exceptional but 4 a 49.55 min b 48.48 min 2 ii the motorway, because the iii the motorway, as a iv the country it has mean lower time is faster minimum c 4 µ 5 a µ = 1.72, 6 a µ = 7, = 8, σ = as the maximum is µ = 0.0618 b µ = 1.74, σ = 0.0906 1 s 3 x = 4 b n σ = σ 90.63, Practice = raw actual = c Student’s 2.45 µ = 11, σ own = 4.36 2 The mean x = −7.5 y = 3.5 is hours, s = The data aected but the standard deviation is to µ = µ 2.94, σ µ = 10.46, σ a i 63 = a distributed normal about the mean and distribution. x = 7.84 Katie people, could s = 2.85 1 assume that 5 and 11 68% people in of carriages would have them. kg practice a = µ = 4.4, σ = 1.36 b µ = 24.5, σ = 2.93 d µ = 13.3, σ = 6.06 6.67 µ = 4, σ = 0.76 5.34 2 kg 53.55 follow = 1.27 = 15.03, σ c b 18.72 2 c 2 = −1 1 symmetrically n 1 b 460.16 s hours 9 Mixed a 39.53 not. between 1 is 20 d Practice = n 1550 2.45 or or x −1 = answer c e ∑ x 4 appears d or 33.02 n b data lower 4.32 σ the value 5 roads, Either ii 9.45 With water: With food: µ = 13.6, σ = 2.2 kg On average the mean µ = the was 15.7, σ = 2.15 strawberries greater and given the food standard Answers gave a better deviation yield, was lower. 3 21 3 µ a b = an food. 49.2 c σ 55.2, On About and This b 5.96 is 5 4.25 Practice day 68% 61.2 g result, the of of standard abnormal 4 = average hamster the time, will the eat about hamster 55.2 will eat g between 1 food. and x (1.25) = 2, x (1.25) = 6.5, x he = a 4 d deviations less should than be normal, so it 2 of is b 16 an 81 e 25 2 2 a x + 3 a x x b x 4 1.5 x = 1.5 f 49 3 4 b 5 2 c x c x 13 3 4.25 125 3 3 worried. c 2 d x d 3 7 3 6 2 = 9 4 5 µ 6 a = σ 28.15, = 3.84 15 e x = 200.5, s = 2.655 b x = 200.5, s x 7 x = 9.5, s x = 9.5, s = = x x f 2.49 Practice x = x 16 2.80 −1 3 2.62 −1 1 Yes, because mean is close to 10 and assuming a normal 1 34% of the values will be between 9.5 and b c many will be over 8 f 216 in Patient x = 1: 91.3, s = x 5.12 high blood pressure a 5 b e 81 f 2 c 2401 d 4 c 9 d 2 3 treatment −1 3 Patient 27 context 2 1 256 10. e Review d 27 8 12.12, 125 so 64 1 a 125 distribution, Student’s own answers. 2: 1 x = 78.3, s = x 2.62 no 4 treatment a b 4 b 2 b 3 b 2 −1 9 Patient x = 3: 78.7, s = x 2 x = 75, s = x lie more tests needed Practice 5.53, s −1 Provided 68% 15 −1 = x the data between is 70 5.6 −1 normally and 4 7 7 distributed you can 1 a 2 2 a 7 3 a 2 80. 8 a x = 3.2, s = 0.49, s x b x = 1.95 = x 0.5 a x = 1 s = 6.48, s x Provided 25 now = x the data and 68% 39, of is the however mothers were 2 d 2 d 2 3 1 4 1 3 1 4 c 3 × 1 2 2 2 × 5 7.82 normally ages 30 1 × 7 1 distributed you can 1 of rst years ago time mothers 68% of the lie between 22 and 28 years ages old. 1 1 assume e 2 a 2 2 3 2 × 5 f 2 b 3 × 3 between of rst 7 5 4 1 3 6 6 time d 4 3 2 4 that 2 2 1 1 1 × 3 1 b c d 1 kg 31.79, 2 2 2 4 2 c 3 15 3 5 7 3 2 assume 1 6 10 c 7 6 3 E5.1 1 4 ( 15 Y ou should already know how e 2 g a f 1 a 8 x b 2 a 3 3 a 2 5 ( 6 2 c 8x b 4 c 6 b 2 c 2 n m 1 ) 2 ( 1 n m × 5 m n = m n ) mn mn 2 × 5 to: 1 6 1 1 + n m ) m = + n ( mn a h 1 1 n m ) a m = n mn a 5 Practice 5 1 d 8 e 4 f 1 6 0.1 1 a 2 b 3 c d 5 e 6 7 11 1 1 4 a c b 36 6 8 4 f 6 5 3 g 4 5 15 2 h 10 9 7 6 3 i 2 5 j 2 25 3 1 d 2 e f 3 4 2 2 12 5 a 2 b 3 7 3 × 2 6 4 c 2 × 6 7 3 d 5 2 e 6 7 7 Practice 1 12 1 a 4 2 h b 2 c 2 d 5 f a x = 3 b y 3 = Practice 1 x b 3x b 2 5 x 32 3 3 d e 8 f 6 1 f 4 x g 0.2 h x 1 = 8 32 2 b x b y (32 ) 5 = (2 5 ) 3 a 4 x 2.4 b = 2 1 c 4.6 4 c = = 1 3 2 2 1 5 3x 2 1 1000 1 1 x 1000 6 5 a 2 2x a c 3 d 1 4 = 10 c 2 x z 3 1 a c 10 2 3 2 j i 3 5 h g 3 3 3 5 2 1 e e 5 2 3 a g 1 2 2 3 5 5 f 1 x 100 Answers = 1024 5 a 3 b 2 7 Mixed practice Practice 1 a b 3 c d 3 3 2.32 2 0.661 3 1.7 4 0.232 5 0.58 6 2.58 7 4.2 8 4.3 5 e f 2 g 4 Practice 2 1 7x 1 c b 4 x a 1000 b 100 4 307 850.7 300 000 × ≈ 307 851 1.013 t c 350 000 , = 300 000 × 1.013 year = 2012 4.31 = 5 years 25 25 c b = 27 2 27 a P (t) 1 d c 9 4 and t 1 a 303 900 2 b 3 3 3 3 a 1 5 3 2 2 1 1 d 3 8 Time 27 16 Time t 5 5 2 5 a 2 6 a 25 4 3 b period Amount (hours) caeine of (C mg) 7 c 2 c 7 c 2 6 d 3 1 b 08:00 t = 0 120 13.00 t = 1 60 18:00 t = 2 30 23:00 t = 3 15 2 3 7 7 a 3 2 b 2 6 3 d 1 1 e 2 f 8 g a r = 0.5 h w 12 12 b 3 12 C (t) = 120 × 0.5 7 c 8 Student’s own C (7) = 120 × 0.5 0.02 = 120 × 0.5 = 0.9375 answers w d , 13 hours (12.55) 12 3 9 1 7 2 a b 12 5 c d w 4 2 5 4 T 5 a = 72 × 0.98 , w 60 = 72 × 0.98 , w = 9.02, thus after 10 weeks 2 1 10 a x = b x = 2 c x = 27 3 5 year 9 6 5 11 a b 12 Mathematics 5 is c as old 9 as d 1 e 2 population 0 100 000 1 90 000 2 81 000 3 72 900 3 × 3 = 1728 man. E6.1 t b Y ou should already know how P (t) = 100 000 × 0.9 to: t c 25 000 = 100 000 × 0.9 , t = 13.15, thus after 14 years 7 1 x 2 a Practice 1 125 b c 4 4 2 2 1 1 18 242 2 a years 3 0.866t 3 2 3 a 6 b = −0.866 b A = A 2 3 b c e c 0.265 o 5 3 a 1000 4 a 121 5 a 5 6 a r b 2013 c 5.58 or approximately 6 weeks 52 4 2 × 1.18 = Practice 1 a c log log (to the nearest whole number) 1 500 60 10 937 = = x x = = 2.70 1.77 b log d log 150 45 = = x x = = 2.18 rabbits b 5 wombats b 1.73 b 6224 = 0.0199 years years or approximately c 34 c log 21 months years 5.49 2 e log 6 = x = 2.58 Mixed 2 2 practice 3 2 2 a 8 1 = 64 b 8 e b = 4 c 10 = 0.1 1 a log 23 = x b log 95 = x 7 5 d 4 5 = x 0 = b f x d = log y = x e log log 9 = 2 b 3 log 0.125 = c log 4 10 2 = a 5 125 b a 4 e b 5 f 5 3 c g 2 d 0 d 5 h 5 3 = a 7 a c b c 2 d 2401 a e 4 b 4 a = x b 2.68 e c 3.13 d 2 = = 3.36 3.20 (3 (3 s.f.) s.f.) b x = 2.86 (3 s.f.) d x = 6.49 (3 s.f.) b 3 2 c 0 1 f g a 2.81 1.39 2.73 b e b 1.79 2 2.81 1.86 c f c 3.57 1.61 3.0 2 d 3 a d 1 1 a d 3 0.77 5 8 1 1000 m 1 2 4.09 x c = 2 4 7 10 n = 2 a c 3 2 6 x 9 3 1 3 3 4 4 = x 2 = 1000 3 = 1 3 a 1200 12 1 2 3 6 8 47 4 0 d e 1.46 e 0.91 f 0.65 5 Answers 323 7 1 6 a 1 c b 8 2 3 6 a 3 1 i b 2 1 2 3 i 2 2 t 7 a C ( t ) = 4 × 1.055 26 b C (26) = 4 × 1.055 = 16.09 8 a years, 100°C or b in the year d 2 in 2 54.8°C c 5 2 context 4 3 3 a b 0 c 3 2 a 2 minutes 1 1 1 3 i 2020 Practice Review − i 30 2 2 − c c 3.4 b i 7.4 ii 5.27 iii 5.5 iv 5.9 v 1 2 5.9 d c 91 488 815 d 4280 e microns 0 f 2 2 microns g 10 2 a 2.8 b 3.98 3 a 4.2 b 0.005 4 a 110 × 1 h i 7 10 c 2 2 10 π 2 dB, 1 2 recommended b 65 db c 169 dB, a For 2π example b For example 4 necessary 3 π c For 3π example d For example 2 E7.1 2 π e Y ou should know how For example 3 to: 2 1 1 already a b 3 c Practice 5 2 2 π 2 a, b Suitable graphs 3 a Amplitude: of sin x and cos x 1 2, frequency: a Amplitude Vertical dilation of scale factor 3, vertical 1unit in the positive y frequency = 4; period = 0; vertical translation = a Circumference = 24π = horizontal 2π Amplitude = 1; frequency = 3; period = ; horizontal π; horizontal direction 3 π 4 ; 0 translation b of 3; 2 shift= b = 2 75.4 shift= cm ; vertical translation = 2 3 b AB = 4π = 12.6 cm c Amplitude = 0.5; frequency = 2; period = π shift Practice = ; vertical translation = 7 1 8 1 2π π π a π b d Amplitude 10 5 2π 6; frequency = 3; period = ; horizontal π shift 2π e = d 3 12 18 π c 7π f = ; 5π g vertical translation = −3 3 h 2π 5 10 6 e 9 Amplitude = 1; frequency = 3; period = ; horizontal 3 5π 5π shift= 4 2 ; vertical translation = 2 j i 3 3 a 30° b e 157.5° f 120° c 135° d 108° h 240° 2 a y 160° g 75° 5 i 300° j 225° 1 2 3 A = 4 θ r π 2 (2π , 3) 4 3 2 Practice 2 2 1 a 31.4 cm b 70.7 cm 2 a 39.0 m b 0.292 c 6 hours c 1 591 500 π 1 km y = x 3 rotations 2 3 12.00 4 a m 0 π π 3π 2π x 61π b 143.7 m 2 2 2 Practice b 3 y 1 2 3 1 a b c 3 2 2 0 x 3 d e 0 f 0 π π 3π 4 2 4 1 2 3 2 2 h g i 1 2 2 y 3 3π 2 a b and 4 3π and 2 324 3 π 2π and 3 Answers 3 7π and c and e 2 5π 5π 3 4 π d π 7π 4 4 = cos (4x − 2π) − 1 π b y c 2 Amplitude horizontal The 1 = 1.3 shift amplitude heights of m, = is tides. period 3, = vertical the 12 hours, shift maximum The period is = 0.67. rise the and time fall in taken the for a full 0 x π 2π 3π 4π 5π cycle of high and low tide. The vertical shift is the mean 6π 1 2 c depth over time, depth over time. 1.97 and the horizontal shift is the mean m 3 d Important for people whose livelihood is from the sea, e.g. 4 y = 3 sin(0.5x) shermen, 2 navigation, coastal engineering, etc. 5 (3π, 3 5) a 2π h 6 h(t) = t − 7.5) + 94 30 250 d y (14.7, 200 1 y = 0.5 sin(2x − π) − 180) 2 150 0 π π 3π x 2π 100 1 2 2 (30, 8) 50 2 0 3 t 5 π 3 y = 2 sin 2 x − 2 i y = 4 π x sin 2 Amplitude 30 y ii = 4 ( x cos − π y = π 3 sin x 6 y ii = 3 cos x − = 6 sin 4 x + 3 y ii = 6 cos π 4 x radius to make of the one wheel); complete period = revolution; shift = 7.5 min ( 6 of the period); vertical shift 137 = 94 m, the maximum height above the ground. m − + 3 2 (the 4 − m time 4 + π y 86 (the c i 35 1 3π + 4 = minutes 3 − c 30 ) horizontal i 25 1 + 3 b 20 b 1 a 15 1 4 10 50 4 a 8 π h h(t) = t − + 3π 7 4 5π d i y = 5 sin 3 x − 10 6 π y ii = 5 cos 3 x − 10 20 3 16 (12, (20, 10) 10) (28, 10) 12 Practice 6 8 1 a π h(t) h = π t 1.5 sin + 5 4 2 2 0 t 1 4 8 12 16 20 24 28 32 4 0 t π 2π 3π 4π b 1 Amplitude fromthe = 3 m (The platform is 6 range m). of the Period height = 8 s, of the the time car it 2 takesto b Amplitude vertical The the = 1.5 m; translation amplitude buoy. The is period = the = 10 s; horizontal shift = 2.5 s; 0. maximum period is the rise time and taken fall for in one depth rise of of the buoy. The horizontal shift means that and at 0 maximum height); of the buoy was above its mean height. The is the mean height over the 10 i 0.464 m ii 1.5 b Amplitude a h = shift 22.5; = vertical cycle 12 shift = s on to 7 the reach m (the track; the height amplitude months, over 1.3 sin (t + 3) + period = 12; horizontal shift is half the dierence temperatures in one of the year. and the the time lows. 12 The taken for vertical a full shift is cycle the of period (12, mean temperature (Answers from GDCs will vary): y = −22.5 π cos 6 1.97) Mixed 1 b 0 t 20 e c 5π 3 4 28π 9π g f 36 d 5 3 25π 8π 8π 4π a 15 16 + 54.5 practice π (6, x 1.97) 1 4 is months. 1.97) 0; temperature c (24, (0, = maximum The 0.67 6 2 of 54.5. minimum highs π = takes m 3 h(t) (it s. 12 2 complete the and c s vertical The translation 12 fall s vertical height one shift= theplatform). 5 cycle complete horizontal h 2 15 0.63) 1 4π i 35π j 9 9 Answers 325 2 a 15° e i b 75° 138° 72° c f 252° j 51° 270° g d 99° f 96° h 1 2 1 b c 3 2 3 3 g 1 b y = −1000 the number of the tire of revolutions gives the total distance tire. π cos of radius + 4000 x c 6 4866 d 3500 h e 3 2 the 3 2 f e by the or d 2 measure by 3 9 a radian travelled 1 3 The multiplied 45° End of April/beginning of May, and end of August/ 2 beginning of September 1 i 0 j 2 Review 4 5.00 in context m 2π 1 5 a a = 2; f π; = p = 2, hs = 0; vs = c b 15 π a = 5; f = 4; p = ; hs = − ; 2 a = 0.2; f = 6; p vs = a i t ( x ) = a 12 sin (bx) 0 2 π c d 30 3 π 2 b 5π 7π π a 0 ii x represents the time after launch that the stone is in theair. π = ; hs = − ; 3 vs = iii −1 a represents the maximum height of the stone during 3 its ight. This is inuenced by the catapult’s size and π d a = 3; f = ; p = 4; hs = 3; vs = 8 hs = 2; vs = −1 power. 2 iv b represents the frequency, or number of cycles per 2π π e a = 1; f = 6; p = ; The more cycles there are, the closer the point of 3 impact. 6 a y away y = 3 cos (2x) − The the smaller point of the number of cycles, of t ( x ) the further impact. 3 π 2 v Domain: x is from 0 to , range is from 0 to a b 0 b x π π 3π c represents the 2 the horizontal shift, which is the position of 2π 2 catapult from the origin. The catapult can be moved 2 toward the target to hit it, for example. 4 π c c Domain: x from + , to 6 b (stays the c range: t ( x ) from 0 to a b same). 8 d Instead of moving backwards if the the catapult target is too up, it close, can for simply be example. moved By y b moving the catapult up, the sine curve does not model 1 the trajectory of the stone once the stone goes below the 0 π π 3π catapult’s x 2π sine 1 2 height curve – makes it it would keep advance going down whereas forward. 2 e i Domain: x from 2π 6π, to range: t ( x ) from 0 to 8 π 2 y = x− − 4 π 2 ii t (x ) = 8 sin 0.25 3 x − f 4 i (2π, iii Max iv Domain , 2 0) 2π 5, at the x (4π, ii height < < 6π point 0) (3π, 5) 5 x is from 2π to 4π, range t ( x ) from 0 to 5. 6 c E8.1 y 1 Y ou 0 should already know how to: x π π 3π 2π 1 a 4n + 1, 81 1 2 2 b 2 c π y = x − + 2.5n 1.2n + + 27.5, 41.5, 22.5 65.5 3 4 n 3 2 a 480, 960; 15 × 1 2 25 n 4 b 1.5625, or 0.390625; 100 × 1 (0.25) 64 5 2 c 6 n 2 , ; 3 162 × 9 1 3 1 1 3 3π 7 a 8 a y = 2 sin x − of The circumference is c d e i 1341 m = sin 2x the the the tire depends distance i 72 cm 2398.9 32 6 m 6, 10, 15 b n(n 1) 3 4 the travelled in a 2, 5, 8, 11, 14 b 6, 12, 18, 36, 72 diameter. one Practice 1 tire. ii 1424 m ii 86 ii 2570.2 iii 1676 cm iii 105 m iii 3426.9 Answers 1 465 2 5 a 930 b 6 a 2601 b 1131 3 2112 c 51 m 1.2π i 3, 2 − on 1, 2 circumference of y b The revolution b + 1 4 π a 900 cm m 2550 4 18 396 the 7 80 1 1.5 2 4 r a = r so = ± 24 8 a 91, so correct. b 385 c 2870 d a b 9 4 2485 = ± 96 190 96 If a 96, = S = 128 = ∞ 1 Practice 1 2 4 If 1 a 459 b 198 c a 513 3 a a 4 725 = b 15, d = r = −96, S = 0.9 −76.8 6 x = 15 7 x = −3 10 380 4 b 5 Practice = ∞ 5 2 a 438 47 c Mixed 5029 practice 120 3 1 a b 208 c 1365 2 2464 9801 3 210 4 48.2 6 1071 7 159 (3 s.f.) d 62 499.84 5 394.0625 28 394 1 a 185 b 56.4 c 780 d 351 (3 s.f.) 8 ≈ 1050 (3 s.f.) 27 2 a 3 720 825 b 441 c 4 308 5 924 d 1904 6 13.2 e 3630 2 9 Practice 1 a 630 3 10 41 2 a b 11 37 700 12 4 14 96 15 r = 18 x = 4 c 333 11 13 a = − 56, 16 a = 36, 19 165 d = 24 1 413 336 a = 9 b 23 327.5 c 23.8 576 907 d 1 797 558 b 6075.04 c d = 6 a constant 3 420.04 17 2 d x = 5 10 5147.5 2 20 n 3 a x = 396 21 1240 cm (3 s.f.) 1 b 2 × 3 6560 n Review Practice 1 1 a 26.622 976 b 39.921 875 c a 3 8 388 600 6 a 19 530 a 8 b 329 554 400 c + (the 1266 b 4 485 (3 s.f.) 5 2n = ± 2 b 1778 or 8.65 (3 s.f.) 8 n = 30 4.16 as 3 6 n b u = 3 × increases by amount 180 million. It is only an estimate because she has estimated 602 rate at −1 a attendance might inuence will fall, and other factors, such attendance. 144 = b 4 which reviews, = 1.2. There is a common ratio. 120 100 1 capacity dierence). c 120 Practice week common 28 the 7 each 484 275 610 2 r context 917 503.125 Since 2 in 5 3960 (3 s.f.) n 4 c 65 535 d S = a Because each new machine connects to the server and n 1 1 073 741 823 15 other 2 a 11 b 660 3 a 8 b 32.8 4 a 962 b 1 969 214 b c 2 2 mm mm Adding 1.97 the d 120 000 1371.6 a = mm (54 = 20 + 5 × 2 = u c = 20 + 2 (n − 1) = c 7 = 16; Day 456 the 2 + 3 + … 16th (7 = 0.8. The sequence has a common 553 392 (to the nearest whole number of followers) 6 a 111 000 b 19 000 c 111 000 7 a 3 b 15 c 20 + 76 000 = 187 000 day depots hours 36 minutes) 7 200 1 a 2000 2 54 b 100 3 156.25 4 a 23 b 5 d 1 a 5 2 a (5, 3 Practice 8) a Yes e Yes b a f , 4, No c Yes g Yes d Yes No h No 1 b 5.98 (3 s.f.) c 6 2 15 r = b (0, 4 53° 7.5) 57 a A b E (0, 1 0, 1), B (4, 9, 0), C (4, 0, 0), D (0, 5, 0, 0), G (0, 7, 0), H c 13 9, 1) ( 5, 7, 0), F ( ( 5, 7, 2) a 7 b 6 5 . = 18 25 to: 9 3 3 b how 4 4 2 know 8 Practice 1 already 9 27 111 should 5 16 c 99 9 Y ou c 35 2 ratio. 750 000 E9.1 Practice n 120 000 25 minutes + 50 n n + 30 6 b 1 inches) b u gives 96 000 a 150 000 6 together 64 m 5 5 connections 1275 2 ≈ machines. Since −1 < r < 1, the sum is nite. 6 Answers 327 Practice 1 2 a 25 a 2 Review cm b 56.648… ≈ 57 9 m c cm 27 b cm 137.2 1 in a (112.5, b The context 90, 25.729 ≈ 26 5 3 4 16.6 cm were 3 a 7 b 3 c 9 e 37 a a 3 OA 14 b to f 9, OB = a EF of equal 9. So OAB is isosceles because it has two = room This is is the space greater hit be so it is possible that some than people targets. from held at realistic ground around level, 4 feet maximum 98.1 feet. above the If the laser ground, 97 feet range. ≈ 193.32 ≈ 687 m m m ≈ 8 m dierence sides (214, 29, 18.5) length. c Area the feet. 23 b 4 in 193 22.5 7.98 = possible length range, ring more GH 2 has 11 2 d not Assume is 1 maximum might c Practice which inches the 3 distance mm diagonal, c 15) greatest 36.3 (3 M(118.5, 22.5, 17); N(120.5, 24.5, 18) s.f.) MN = 3 m 3 3 Practice a 40 This b 14° 54.7° b 54.7° 10.2 b 11.4 1 17° 3 a 4 a 5 a 2 8 m cm 2 b 4 cm c 2 c 10° 4 d 6 d 11° 4 is to a d (99, an a 13.6 m b Practice 1 a (2, d 4, (4.5, 76 4.8° 7 12.3 estimate degree of 29.8, a 415 b She m c because Volume accuracy; the numbers tunnel will ≈ 687 will only m not be have a been perfect m will probably slope will ski have left and steeper right, and not in shallower a straight parts. m c 20.7 d ( s e 134 f 6.87° 155, 268, 59) 5 8) b 5, 8) (13, e ( 6, 7.5, 4) c 12.5, 8.5) f ( 3, (2, 1, 1.85, m 11) −0.15) E9.2 2 (21, 7, 4 ABCD 5 P (1, 2) is 3 a a = 1, b = 3, c = −18 parallelogram. Y ou 7, 2), Q (3, 8, 4), R (5, 9, should already know how to: 6) 2 1 Practice 6 2 a 10.5 cm b 42 cm 2 a 3.76 cm b 45.6° 3 36.1 4 a b 1.75 2 1 a (10, 15) 2 a (9, 1, 3 (16, 4 m b ( b (12, 1, 4) c (7, 12) c (6, 4, cm 2 2, 2) 4, 1.5) 15) 21.25 cm n = 10 : 15 so let m : n be 2 : = −4, b = 1 3. 1 a radians 28) Practice : ∆ABC ∆DEF B F 5 e c Mixed d a practice D E f C A 1 57 cm 2 Yes. (to The the nearest space b centimeter) diagonal is around 25.7 inches long, and ∆LMN drumsticks are usually quite ∆UVW L V thin. u 3 a 4 a (2, 0.5, 6); 7 b (5.5, 3, 6); 9 c (11, 0, 7.5); ≈ 16.4 m; Midpoint = (7.5, 4.5, 5) N M b 5 a 6 a It gains 61 ≈ 6 7.8 meters in m l height. b 22.6° b 43.11° Practice 41.77° 2 2 c No, since the angles are not the 1 a 41.6 2 a 1114 2 cm b 181 (19, 8 OA 9 z 4, b 3402 3 = 1, and OB = 189 A is 15 closer to O 34 67 120° 10 Area = 2 7897 ≈ 178 P 2 Area 32 8 Answers c 2 cm 17) 131 = 2 m same. 2 7 w 9 v 270 = given cylinder. 24.4) 55° the 6 b 4 986 cm cm 968 km line; 2 4 a 130 6 cm a L 2 b i It estimates ii It is an cover the number underestimate, the space of as exactly, tiles the and needed tiles will will have to tile 10 probably to be cut m not leaving 10° oddly shaped sections so extras will be 25° needed. F 5 35° 18 12 Y 5 49° 30° b 2 Area 106 km X L = 25°, X = 30°, Y = 125° cm c 5.92 km 6 Practice 1 a a = 6.3 2 a 91° 3 a r 4 a N = 5 cm 19.0 b b b 103° b = E 6.0 = cm 104° c c = 61.1 c 42° c y = cm 11.0 d D = 73.9° 60° 8 b 2 Area of one face = 27.7 75° c 13.4 km 13 m 2 Total surface area = 111 m 60° Thickness of paint is 1 mm, so volume = 75° 3 111 74 × 0.001 cans = 0.111 m = 111 liters. 8 needed. 5 Practice a 86.4° b 34.8° 3 2 1 a Area = 0.0572 cm Practice 6 2 b Area = 271 cm 2 c Area = 4.01 1 2 2 a 2.86 a, b, in the 2 cm b 0.112 c 49.7 cm c 17.7 cm c, a 4 2 29.1 the cosine rule; three sides and an angle are involved 2 cm b 90.0 problem. 2 cm 2 3 e: cm d, f: the sine rule; each problem involves two sides and 2 cm two angles. 1 2 = × 49 (θ θ = a d 0.80 (2 cm b 74.6° e 95.0 112 cm cm c 132° f 26.8° d.p.) 3 a d Practice 11.7 sin θ) 2 a d = 21.3 = cm b 70.6° e b e = = 8.27 cm c 104° f c f = 24.1° = 10.1 cm 4 15 3 2 4 1 a a = 2 a A 3 a 4 y 5 a 22.9 cm b b b A b x = 16.1 cm c c c B c x = 6.14 Area ≈ = cm 6.50 units 4 2 5 x = = 44°, B = 56° 59.5° = = 82°, B 33.5° = 28° = = 57°, 39.3 C = a 7.79 cm 12.4 1.413 rad c 11.8 cm cm Practice = b 55° 7 cm 1 a A R 4.1 72° 25° Q B 5.5 26° 2.6 39° C P b ∠ CBA = 129°, ∠ CAB = 25° b c c = 2.7 km, distance = 5.3 147° c 9.21 km km Answers 32 9 2 a 14 2 a 146° b 18.1 3 a 77.6° b 122° 4 8.8 km c 241° 50° km 145° E10.1 18 Y ou 1 should log y = already know how to: x 5 y b 95° c 23.7 2 x 3 a = 7 x km y 2 b = y = ± x 2 and + 1 3 3 a N 4 Vertical one unit dilation in the scale factor negative a vertical translation direction. 5 5 Algebraically: f f (x ) = 5 ÷ = x x 113° Graphically: f ( x ) is a reection of itself in the line y = A 430 m Practice 210° 310 1 m P 1 1 a f 1 (x ) = log x b f d f x (x ) = 6 (x ) = 5 4 x 1 c b 3 1 M 97° c 560 f x (x ) = e m 4 x 3 1 4 a 50° b 039° c 112 m d 211 m e f (x ) = 1 e f f (x ) = 11 Mixed practice 2 2 1 a 10.7 2 cm b 63.4 cm 2 d 47.6 cm g 24.7 cm c 34.6 37.6 y cm 2 e a 2 2 cm f 36.3 25 cm x 2 f (x) = 15 × 1.15 1 20 2 2 a 2.81 2 cm b 178 cm b 74.8 (0, 15) 2 3 a 4 a e 0.109 = = 5.8 cm, 10.5 b cm, 15 2 cm = f 6.76 = cm, 14.7 c = cm 14.1 cm, d = 11.2 10 cm, cm 5 5 a = 43.6°, 6 a = 1.71, 7 20.0° b b = = 38.6°, 0.547, c c = = 54.8°, 0.356, d d = = 101° 0.364 0 x 5 8 42.6 5 10 15 20 25 m 5 9 x = 62.7°, perimeter = 66.1 cm P = 15 seagulls 0 Review 1 b in ∠RST = context 85°, ∠STR = 40°, ∠TRS = 55° f (x ) = RT = 14.7 km, ST = 12.0 km d L c log 1.15 c x 1 b 15 1.1 y x f (x) = 15 × 1.15 1 25 20 y S = x 15 100° 9.5 10 86° x R f 54° 5 5 5 T LS = 16.8 3 3 0 km, = log LT = 22.2 1.15 km Answers 15 x 48° 40° e (x) 2 5 12 10 15 20 25 3x log 2 x of x 3 1 d b 1.1 i Domain iii y The is x > graphs −2; are range is reections ii in the f = 10 ( x ) line y = 2 x x f (x) = 15 × 1.15 1 25 1.1 (2.06, 20) 20 y y = x 10 15 8 10 x (x) f = log 2 6 1.15 15 5 (x) = 3 f log 1 (x + 10 5 15 = x 3 4 x 5 (x) f 2) 10 (20, 2.06) 20 2 25 5 0 10 2.06 or approximately 2 8 6 4 x 2 2 4 6 8 10 months. x 4 3 f (x) = 10 2 2 Practice 1 a B 2 a a b f 2 b = 6 C c 10 1 c 8 A 1.2 x ( x ) The the = two line + 1.2 Domain functions y = are is , range reections is of each other in x 4 x. 1 c i Domain is x > −0.5; range is ii f 10 (x ) 1 = 2 1.1 iii y f (x) = log 1 The graphs are reections in the line y = x (x) 1.2 10 1.1 8 y 6 10 4 8 2 x f (x) = (1.2) 6 2 f (x) = 4 log 1 (1 + 2x) 10 x 10 8 6 4 2 2 4 6 8 4 10 2 2 4 f (x) = x 3 6 0 10 8 6 4 x 2 2 4 8 6 10 2 8 x 10 f (x) = x 1 3 f (x) 4 = 10 2 2 + 3 a Domain = ; range = {0}; a = 3 8 + b Domain = c Domain = a i ; range = {0}; a = 0.5 range = {0}; a = 5 + ; + 4 Domain is ; range is 10 1 ii f ( x ) = ln = x x 2 2 The graphs are reections in the line y x 10 2 iii + 1 d i Domain is x > ; range is ii f (x ) = 3 3 1.1 iii The graphs are reections in the line y = x y 1.1 10 8 y f (x) = 2 log 1 6 f (x) = (3x 2) 10 15 x 3 4 12 2 x f (x) = + 2 e 1 f 0 10 8 6 4 2 x 2 4 6 8 (x) = x 3 9 10 2 f (x) = ln x 2 2 6 4 2 − x + 10 6 (x) f 2 3 2 = 3 8 10 3 0 3 6 9 12 15 x 3 Answers 3 31 2 x + 4 e + e i Domain is x > 0; range is 1 1 f ii (x ) = , x > g 0 Horizontal dilation scale , factor 2 iii The graphs are reections in the line y = vertical dilation scale 5 factor 2, in negative reection in the x-axis, vertical translation 3 units x the y-direction. 1 1.1 h Horizontal dilation scale , factor horizontal translation 2 y 3units 10 in x (x) = + x-direction, vertical dilation scale , vertical translation 4 units in the positive 5 8 4 positive 1 factor 1 f the e 2 y-direction. 2 6 f (x) = x 3 3 a Horizontal translation of 5 units in the negative direction; 4 f (x + 5). 2 b Reect the original horizontally 0 10 8 6 4 two in the units in y-axis, the and positive then translate x-direction; f ( x + 2) x 2 2 4 6 8 10 or 2 c f ( (x Reect 2)). in the x-axis and translate vertically 2 units in the 4 negative (x) f 6 = ln(2x) y-direction; f (x 2). 4 1 4 1.1 8 y 10 4 1 3 ln x l f (x) = x 2 5 y = log x = b = hence y = b ln x . 2 a ln a 2 ln a x 1 7 f 6 a y = log x b y = (x) = ln(x) 1 2 5 c = log 2 x 0.2 0 x 1 1 2 3 4 1 Practice 1 a 3 Horizontal translation of 7 units in the positive 1 x-direction, Translate and vertical translation1 unit in the positive f ( x) horizontally unit y-direction. in the positive x-direction, 2 1 b Vertical dilation, scale factor 2 and vertical translation of and dilate horizontally by scale factor 2 3 units in the negative y-direction. 1 c Horizontal dilation scale 5 factor and vertical 1.1 translation 6 4units in the negative y y-direction. 10 d Horizontal translation 2 units in the negative x-direction, 8 e vertical dilation vertical translation Horizontal vertical scale 8 factor units translation dilation scale 5 4, in the units factor reection in 3, in positive the the 6 y-direction. positive vertical x-axis, x-direction, translation 7 4 f units (x) = log 1 (x) 5 2 (1, in the positive y-direction. ( 0) 1.8, 0) 1 f Horizontal dilation scale , factor horizontal 0 translation 10 8 6 4 4 units in the negative x 2 2 4 6 8 10 2 3 x-direction, vertical dilation (0, scale 1.43) 4 2 factor , vertical translation 10 units in the negative f 6 3 (x) = −log 2 (5 (x + 2)) 5 y-direction. 8 10 2 a Horizontal and translation vertical 3 translation units 2 in units the in positive the x-direction, positive y-direction. Translate b Vertical dilation scale factor of 0.5, and vertical f ( x ) horizontally 2 units in the negative x-direction, translation 1 1 unit in the negative dilate y-direction. Horizontal dilation scale factor of horizontally by a scale factor , of and then reect in 5 1 c the , and x-axis. vertical 2 Mixed translation d Vertical 1 unit dilation in the scale negative factor 2, and vertical translation 1 1 unit in the positive Horizontal a C b A translation 1 unit in the negative b a = 2.2 1 dilation scale factor 3, and reection in the w = Horizontal 2 units 3 32 in dilation the scale positive factor 2 y-direction. Answers and a vertical f (s) s = 14 2.2 tells what x-axis. the f B x-direction, c vertical c y-direction. 2 e practice y-direction. translation speed you have achieved. week you should be in for 1 3 a i Domain iii The is x graphs > 3; are range is reections ii in the f x ( x ) line y = = 1 e + d 3 x i Domain iii The is x >−1; graphs are range y 3 f (x) = x f 3 (x) = 3 − 1 f 2 = 3 1 x = x 2 10 8 2 x 0 x 4 (x) 3 2 6 = 4 4 8 x ( x ) y x + 2 10 f line 6 x e the 8 6 = ii in 10 8 (x) y 10 f is reections 8 6 2 4 2 4 6 8 10 2 2 f (x) = ln(x − 3) 1 4 log 4 (x + 1) 2 (x) f = 1 6 log (3) 2 6 8 8 10 10 + e b i Domain is ; range is y > i Domain is ; range is 2. 1 ii f (x ) = The 2 graphs are x = 1 − log x ; x > 0 2 > iii 5 (x ) 4 ; f 5 log 7 iii x 1 ii reections in the line y = The graphs x are reections in the line y = x y 10 y f (x) = 1 − log 8 8 6 (x) 4 2 10 f (x) = x 3 6 4 f (x) = x 3 4 2 1 f (x) = − x 4 1 2 0.2 x f (x) = 5 7 + 2 0 1 6 4 x 2 2 4 6 8 10 12 14 2 0 10 8 6 4 x 2 2 4 6 8 10 2 4 4 4 a Translate the graph 2 units vertically in the positive graph 2 units horizontally in the negative graph 2 units horizontally in the positive y-direction. 6 x f 8 (x) = 5 − 2 b Translate the log 7 2 5 x-direction. 10 c Translate the x-direction, then translate 3 units vertically in the negative 2 ( x + 5) 2 + 8 y-direction. 1 c i Domain is x > 2; range is ii f (x ) = 4 d Reect the vertically iii The graphs are reections in the line y = graph in the in the y-axis positive and translate 2 units y-direction. x e Dilate f Reect the graph horizontally by scale factor 4. y the graph in the y-axis and translate 2 units 10 horizontally 2 (x + 2 f (x) in the positive x-direction. 5) + 8 8 = g 2 Reect the graph in the y-axis, dilate vertically by scale 4 factor 6 f (x) = 2, and reect in the x axis. x 3 h Translate the graph 2 units horizontally in the positive 4 x-direction, dilate vertically by scale factor 2 and translate 2 1 0 10 8 6 4 2 i x 2 4 6 8 unit vertically Reect in the in the y-axis, negative translate 1 y-direction. unit horizontally in the 10 negative 2 reect in x-direction, the x-axis, dilate then vertically translate 2 by scale units in factor the 2, positive 4 y-direction. 1 6 (x) f = log 1 (4x − 8) − 5 2 2 8 10 Answers 3 3 3 y E10.2 16 5 Y ou should already know how to: 12 + 1 a Domain is , range is b Domain is , range is 8 f (x) = ln x + c Domain is , x ≠ 1, range is 4 (4.31, 1.46) (1, 0) 1 2 a y ∝ x so y = kx y b ∝ k , so y = x 0 4 x x 2 2 8 12 14 16 4 3 g (x) = −7 ln (3x − 12) + Horizontal translation 3 units in the negative reection in translation x-axis, vertical dilation scale factor 5 units in the positive y-direction. 12 4(x 4 a y 2) , = 16 which is a function 3 20 1 b f (x ) = 2 ± x , which is not a function 24 1 Dilate f ( x ) horizontally by scale factor ; Practice translate 1 3 horizontally 4 units vertically by scale vertically 1 in the factor positive 7; reect x-direction; in the dilate x-axis; 1 a Domain: x ≠ 0, x ∈ , range: y ≠ 0, y ∈ translate y unit in the positive y-direction. y 6 4 1 f (x) = 1 1 x g (x) = log (2 − x) 10 4 0.5 (0, 0.075) x = 0 (1, 0) 0 x 0.2 0.4 0.6 0.8 1 1.2 1.4 1.6 1.8 2 x 0 y 0.5 1 f (x) = log = 0 x 10 1.5 2 Reect f ( x ) in the y-axis; translate horizontally 2 units in the b Domain: x ≠ 0, x ∈ , range: y ≠ 0, y ∈ 1 positive x-direction; dilate vertically by scale factor y 4 7 a y = log (x b Students’ − 3) 4 own answers 8 f (x) = − 2 x Review in context x 1 The 2 a b standard The standard The a is model standard factor 3 model model reected is in the vertically would be = 0 y x-axis. dilated by vertically scale dilated factor by 4. = 0 0 x scale 2. i The graph of f ii The graph of f is dilated is vertically translated 7.6 by units scale in the factor 0.67. negative y-direction 11 b Domain: 2.20 × 10 26 < E < 1.86 × 10 c c There is no solution for r when E = 0. For the model Domain: x ≠ 0, x ∈ , range: y ≠ 0, y ∈ to y have y-intercepts, translation 4 Horizontal in the dilation it would negative by scale have to include a horizontal x-direction. factor 2120; vertical dilation by 1 f scale factor 26 400; reection in the (x) = 3 x-axis. 4x x = 0 0 3 34 Answers x-direction, 1 8 y = 0 x 2, vertical d x Domain: ≠ 0, x ∈, range: y ≠ 0, y b ∈ Asymptotes: y Range: x ≠ 0, = y 4 and y = 0, Domain: x ≠ 4, x ∈ , ∈ y y 2 f (x) = − 1 4 f 3x (x) = 2 x x = 0 x 0 y = = b 3 a y = 200 The x 0 k = = x 0 is inversely proportional to the current. Asymptotes: x = 0 and y = 3, Domain: x ≠ 0, x ∈ , 20 Range: R (I) = y ≠ 3, y ∈ 20 20 c y hours resistance c b 4 4 0 2 − or R ( x ) = y x I 4 a 50 5 a i hours b 10 hours c 5 hours 1 (x) f + = 3 3 Force and acceleration are directly proportional. x ii Acceleration and mass are inversely = x 0 proportional. y b i Force = 3 Acceleration ii 0 Mass Acceleration Practice 2 d 1 a h = −3, x k = Domain: x −7, ≠ asymptotes: −3, x ∈ , x = Range: −3, y y ≠ = −7, −7. y Asymptotes: Range: y x ≠ 0, = y 2 and y = 0, Domain: x ≠ 2, x ∈ , ∈ ∈ y b h = −2, k Domain: = 0, x ≠ asymptotes: −2, x ∈ , x = −2, Range: y y = ≠ 0, 0. y ∈ 1 f (x) = 4 c h = 5, k = Domain: d h = 0, k = Domain: 8, x asymptotes: ≠ 5, x −11, x ∈ , x = ∈ , x = Range: y y Range: asymptotes: ≠ 0, x 5, = ≠ 8, 0, y 8. y ≠ y = x 2 ∈ −11. −11, y ∈ . 0 e h = 1, k = Domain: π, x asymptotes: ≠ 1, x ∈ , x = 1, Range: y y ≠ = π y y a Asymptotes: x Domain: 0, x ≠ = x 0 and ∈ , y = x 0 ∈ x 2 = π = 2 −4. Range: y ≠ −4, y ∈ y e Asymptotes: Range: y ≠ 5, x y = −2 and y = 5, Domain: x ≠ −2, y ∈ , ∈ y x = 1 0 f (x) = − 4 1 x 1 f (x) = + 5 1 x x 0 = + 2 −2 x y y = = 5 −4 0 x Answers 3 3 5 f Asymptotes: x = y ∈ 3 and y = 1, Domain: x Asymptotes: ∈ , ≠ 3, x y = 2, x = 4 1 y Range: ≠ 1, e Horizontal translation of unit in the positive x-direction, 2 y reection in the y-axis (or in the x-axis), vertical dilation scale factor (or horizontal dilation of scale factor ), 5 2 vertical of 2 5 translation of 8 units in the negative y-direction. 1 x = 3 Asymptotes: y = y = −8, x = 2 1 f 0 Reection in the y-axis (or in the x-axis), vertical dilation 1 x of scale factor 13 (or horizontal dilation of scale factor ), 13 1 f (x) vertical = + translation of 11 units in the negative y-direction. 1 2 x − 3 Asymptotes: Practice 1 3 a y 1 = − 5 y b b y d + = + x 4 2 3 4 y y = + 4 b y = y = + x x x 0 4 3 + 2 4 i h > 0 horizontal translation in the positive ii h < 0 horizontal translation in the negative i k > 0 vertical x-direction translation in the positive x-direction d y-direction y ii k < 0 vertical translation in the negative y y-direction 1 Practice y 3 1 a f (x ) + 1 1 y = x 1 = − 1 = = x 4) 2x + 1 8 x 0 (x ) y 1 x 0 3 3 1 f 3 1 4 x 4 1 = 2( x b x 0 3 c b − + d 1 = x a = 2 1 5 y x 3 1 y 2 = 1 x c 0 7 1 a = 1 = x 4 x y 1 y −11, 4 x c = a 1 = y = − 2 = y 2 = 1 x 1 (x x 3) 3 3 1 1 4 c f (x ) = + 8 = e f + 8 − y x 3 3 y f (x ) 2 a 4 + + Horizontal x-direction, = 2) + 2x translation vertical + of scale 6 + = 1 of in the scale vertical − 1 x negative factor 3 (or translation of 5 units x 0 horizontal = x 0 3 1 ), 1 x y units dilation factor − 4 y of + 4 1 dilation 3 3 = −( x = 3 2 d y 4 x 1 1 y 3 = 1 in x x 3 1 3 the b negative Horizontal vertical y-direction. translation dilation of Asymptotes: of scale 2 units factor 5 in y the (or = 5, x = − 6 positive horizontal x-direction, dilation 7 5 of 2 a y = − b − 1 y = 1 scale factor ), vertical translation of 3 units in the positive 5 y-direction. + 9 x x 6 1 Asymptotes: y = 3, x = c 2 y = 6 − + 12 d y = − + 8 x + 5 x + 3 1 c Horizontal translation of units in the negative 10 3 e x-direction, vertical dilation of scale factor 3 (or y = − 3 x 1 1 dilation of scale factor ). Asymptotes: y = 0, x = − 3 d Horizontal reection translation in the y-axis of 4 (or units in the in the positive x-axis), x-direction, vertical dilation 5 scale factor 2 (or horizontal dilation of scale 2 vertical 3 3 6 factor ), 5 translation of 2 units Answers in the positive 3x − y-direction. of 3 8 + 1 f = horizontal 3 x y = 4 x − + x + 2 4 = x + 2 3 Mixed practice 2 a g (x ) 5 x 1 a Domain: x ≠ 0, x ∈ , range: y ≠ 0, y 1 = x = 0, y = g (x ) = + 1 − 2x ∈ , 3 asymptotes: b 5 c 0. g (x ) 1 12 = d g (x ) = 1 − 3 x 4 x y 3 a Horizontal translation in the y-axis of in the positive 9 units Asymptotes: x = of reection x = 2 2 (or and y units in the in the positive x-axis), x-direction, vertical translation y-direction. = 9. 0 y y = 0 0 x 5 y = x 1 g(x) = + − x b Domain: x ≠ 0, x asymptotes: x = ∈ , 0, y range: = y ≠ 1, y ∈, 9 2 0 x 1. y 2x 19 1 g Inverse: (x ) = x b x = Horizontal 9 translation vertical dilation of factor of of scale 1 unit factor in 3 the (or negative horizontal x-direction, dilation 0 1 y = 1 scale ), vertical translation of 3 units in the 3 negative 0 y-direction. x Asymptotes: x = −1 1 y = and y = −3. y + 1 x 3 h(x) c Domain: x ≠ asymptotes: 2, x x = ∈ , 2, y = range: y ≠ −8, y = ∈ , 3 x + 1 −8. 0 x y x 0 2 y = 3 8 x 1 Inverse: 2 (x ) h = 1 x c y = Horizontal + 3 translation of 5 units in the positive x-direction, −8 reection in the y-axis (or in the x-axis), vertical dilation 1 scale factor 10 (or horizontal dilation of scale factor ) 10 Asymptotes: x = x = 5 and y = 0. 2 y d Domain: x ≠ asymptotes: −3, x x = ∈ , −3, y = y range: ≠ 2, y ∈ , 2. y 10 k(x) = 5 x 0 y = x 2 0 x 4 x = −3 y = + x + 2 3 10 1 Inverse: k (x ) = − + 5 x Answers 3 37 of d Horizontal translation of 1 unit in the positive 600 x-direction, 4 reection of scale in the factor y-axis 4 and (or in the horizontal x-axis), vertical dilation of scale a translation of 1 unit in the positive mg (3 s.f.) C b = + 50 − factor + 12 x 3, c vertical 22.7 dilation Horizontal translation of 12 units in the negative x-direction, y-direction. reection in the x-axis vertical dilation of scale factor 600, OR vertical Horizontal reection translation in the of y-axis 1 (or unit in in the the positive x-axis), horizontal dilation of scale factor in the positive y-direction. context of 1 unit in the positive 1 854.91 2 a AUD = 1 1 x-direction. slow pipe = p 3 p − and y = 1 + b 2 x in ), 4 3 translation Asymptotes: units 3 (or factor vertical 50 dilation Review scale of x-direction, vertical 4 of translation 3 p 1. 3 1 1 1 + c y p = , 3 p Time p = 10.5 hours. 14 to ll with slow pipe = 31.5 hours. E11.1 0 x 4 m(x) = + 3x + Y ou 1 should already 1 a b 4 ( ) c 3 3 2 translation in 300° the of y-axis 2 (or units in the in the positive x-axis), 1 2 or a b 2 reection d 2 1 Horizontal 30° = 3x e to: 4 3 1 how 3π 2π Inverse: know 2 c 1.07 (3 s.f.) 2 2 x-direction, vertical 3 a 71.3° (3 s.f.) 4 Horizontal b 30° dilation 1 of scale factor 5 and horizontal dilation of scale factor 4, dilation of scale factor , vertical dilation of 2 vertical translation of 6 units in the positive y-direction. scale factor 3, vertical translation of 5 units in the positive OR ydirection. Horizontal translation of 2 units in the positive x-direction, 3 reection in the y-axis (or in the x-axis), vertical dilation of scale 5 x = or factor (or horizontal dilation of scale factor x 5 6 a ∠B = 25.7° (3 s.f.) b 4.26 ), Practice translation Asymptotes: = 5 4 vertical x 2 4 5 = 2 6 units and y in = the positive 1 y-direction. 1 6. a 30°, 150° b 104°, 256° c 45°, 225° d 225°, 315° e 143°, (3 s.f.) y 5 n(x) = + 8 6 323° f 2π 2 3π x 3.73 e π = + 4 x 1 p (x ) 3π i 2 2π 4π 5π 3 3 3 2 3 0.464, 2.68, 3.61, 5.82 5 = horizontal translation of units, vertical π 4 x π 5.64 24 l f 3 3.79, k 2 2 f 6 π j 5 (x ) 4.86 7π 6 3π 1 3 , h 4 5π , c 4 1.43, 7π , 4 4π , 4 3 2.56, g n 210° 3π b 3 0 π 4π a d Inverse: 150°, 4x 5 5π 4 π m n 1.05, 1.91, 4.37, 5.24 p 1.11, 2.16, 4.25, 5.30 1 dilation of scale (or factor horizontal dilation of 3 scale 4 factor 2π 4). o 5 Asymptotes: x = and y 3 = 0, π , , 2π 3 0 π 4π , 4 3 4 π y 3 3π 5π a 7π , π , 0, b 4 4 4 7π , 2π 4 11π 1 p(x) 4 = 4x 2.30, , 3.98, 6 x 0 b 5 Practice 6 2 3π 1 a θ 4π = b 4 d 1 1 Inverse: p (x ) = = c = 3 2π 4π 3 3 , 2π 0, + 4 x 3 3 8 θ 5 θ 4 Answers e θ = 0.068, 0.56,1.32,1.82, 2.58,3.07 = 3π 3π q 4 2 3π f 5π 11π g 8 8 π 5π 18 18 13π = 8 x 13π 17π Mixed 18 18 1 5π x h 7π 13π 15π π = θ i 8 8 8 = π 0, 8 a 90°, d 6 3 16.6°, π = x k π 5π 2 6 150°, e No 2π 3π a 3 x = 0.955, 2.19, 4.10, π, 0, 2π 5π 2π 4π π 3 5π 3 3 π a 0, 180°, 0°, , 2π 3 360° 75.5°, b 180°, d It 41.4°, is not and 180°, an thus 319° e identity, not 210°, 3 b true 30°, since for Practice all 150°, it is 210°, true values of π 5π 13π 17π 12 12 12 12 (1 a 225°, sin x + sin tan x when sin x = cos x, 3 5 x) ≡ cos − cos x ∠C = > a (θ 30°, c ∠C ∠C d 2 a 12.8° = ∠Q or ∠C (∠C (∠C 70.7° = ∠P or 53.1°; = 0°, ∠Q = p = ≡ ∠Q = = = −sin 180°, π π 6 2 ∠Q ∠P 43.9°, 34.2°, 13.2°, 3 70.0° 5 39 6 a c 7 m 1 0 = = or or < Quadrants 0. sin θ If 270° 360° 11π 3π π 3π = I and tan θ 0, b 90°, d 109°, 5π b 6 5π 9 IV = 120°, 0. If sin θ 240°, 180°, < 0, 270° 251° 7π c , 2 4 4 4 0, π, 2π 4 π π e 6 x 12 It 13 a = 167° = = = isn’t 6 = isn’t 4π 7π , 4 3 3 is an B = identity 36.9° ∠P = = 124°, 11.3 ∠P p = = or because B = it is 143.1° true for all values 4 θ of b B = 60.3° or B = 119.7° in b T = 65.4° or 34.6° possible) 1 a 2 7.70 I = 3 a 74.6° p = 9.93 cm or ∠Q = km or or 105.4° 2.08 km 127°; 228 m or p = 31.4 Because 427 m with p = 44.4 the given information, there are two possible cm m or ∠Q = for the position of B (because there are two 146°, solutions for the angle B ). m 127°, 6.63 context cm 81.1°, 110.1° 7 2π f 109° 96.9°; 3.93 ∠P p 35.0°, 17.0°, 2.91, 3.38 2 possible) c d 16π 9 120°) possible ∠P 14π 9 0. solutions c 10π 104.6° 139° ∠C ∠P 23.1°; = tan θ a b b b 0, d x) 5 41.4° = ∠C 9 − 1 75.3° = > 150°, Review b 8π 9 x (cos Practice a 315° sin θ If π 1 4π 9 b 2π d x 11 tan x cos x 306.9° 330° only + or 4 1 53.1° 330° c a 6 360° 10 2 6 3 3 90°, 284°, 5π 3 c 5π 0, 3 4π tan θ 3 7π f 3 a c c 3 π 5π 3 4 2 4π 3 e , π, c 3 5π e 3 π , π, b d 3 π 4 3 3 π 315° 5.33 π a 338° 225°, 18 18 2 1 158°, f 5π 4 d Practice c c 3 3π l 330° solution b , = b 163.4° 3 π θ 270° 2π , π j practice = 8 p = 18.1 km or ∠Q 4 = m 145°, 4 km 199 a 16.2° m triangle b 1 triangle triangles d 2 triangles a B 68.3° 9.65 8 b Either 235.2 million km or 44.8 million km. E12.1 63.7° 48° A C 10 Y ou should already know how to: B 8 1 a 2 x = 0.699 2.73 4 y = 3x b 1.10 3 x c 2.58 3.73 111.7° = −1 48° 20.3° A 4 x C 10 Inverse function: y + 4 = 3 b 8 a 9.7 2 km or 3.7 km b 10.9 m or 5.4 m Answers 3 3 9 1.1 x y 1 y = 3x 1 ( x ) = h c 4 4 10 2 15 1 1 y = Domain x of h is x > − 10 ; range of h is . Domain of h is ; 2 1 5 x y + 1 4 range of h is y > − = 2 3 0 10 x 5 5 10 1.1 15 5 y 1 h (x) 10 15 y = x 10 The functions x + 11 are reections in the line y = x. 5 h(x) 1 5 y = 2 5 3 x 0 10 5 5 10 15 5 Practice 1 10 1 a log 12 b log 15 c log 200 1 z d 2 3 3 9 x e x x x log 2 + e f log d (x ) = j ; 4 y + 1 ln 8 Domain e 96 y a ln a + ln b b ln a ln b c 2 ln a + 1 ln a e 2 ln a f ln a + 2 ln b ln b Domain of j ln a x e 2y a 1; range of j is 1 ; range of j is y > 1. 1.1 a ln b h 3 ln a 2 ln b i y (ln a ln b) + y b y x c x 15 y d 2x j(x) y 4 > 2 2 3 x + is 1 3 is 1 d g j 1 1 2 of x 2x f + 3y + 3x g 2 b y 5x + 4y 5 2 x 1 j 1 = 10 3x (x) 1 c (6x + 8y + 3) d x y 1 x 3 5 2 10 15 5 Practice 2 10 1 1 a f + (x ) = log x + 3; Domain of f is ; range of f is 15 2 1 Domain of f 1 + is ; range of f is n 2 1.1 g (x ) f = ( x ) log x scale = n factor log x g (x ) = n log x is a vertical dilation of n y f (x) 15 (x ) 3 = − log x + 2. Reect the graph of y = log = x-axis x and x in the 3 3 y translate it vertically 2 units in the positive 10 ydirection. 5 1 f (x) 4 a i 0 = 2 10 8 log log 8 − x log 2 x = 3 − x log 2 2 x 5 5 10 15 2 5 ii log (x + 3) = 2 log 2 (x + 3) 2 10 b i Reect y = log x in the x-axis then translate 3 units 2 vertically in the positive y-direction. 2 x e 1 b g 1 (x ) = , x > 0; Domain of g is x > 2 + ; range of g is ii Translate and + 1 Domain of g 3 units horizontally in the negative x-direction, 2 is dilate vertically by scale factor 2. 1 Range of g is y > 0. Practice 3 1.1 n 3 p 4 1 a log p (x 2) 2 b q log c y ln 3 x q 15 1 g (x) x d y = ln 2 (x 2 5 a a b a + x b 5 10 a) e 2 x 5 1 (b d 0 10 c 2 15 5 3 a b 10 c 34 0 Answers ln(x ln(x ln( x 3) + 2) + + − 3) − ln(x ln(x ln( x + + + 3) 3) 4) ln ( x 2 (x g (x) 1 4 f 2) b ln e x 10 e + b c 2a + c 1) ) d ln(x + 1) ln(x + 2) ln(x ln(x + 1) ln(x 3 2) x e ln(x 6) + + 2) ln(x 2) 1 c f 2 ln x + ln(x + 2) + ln(x 5) ln(5x h 2 e (x ) + 1 = 20) 3 1 Practice 4 Domain of h Domain of h is x > ; range of h is 1 1 1 a 2.81 b 1.29 c 2.10 1 is ; range of h is y > 3 d 0.732 e 1 f 1.16 x 5 4 + 1 k d Practice (x ) = ; Domain of k is ; range of k is 7 4 ln 7 1 2 3 1 a 1 b ln x ln x 1 c d ln x 5 5 Domain (ln 10 x ln x c a y 2 ln x = 3 + d x = b y = x b x = 1.91 c x = log ( x ); x = 0.693 b x = 0.79 c x Translate the positive a x = 0.397 b x = 0.417 c a c a = 1.044 8 4 log 4 (x 9); x = x 0 = or 1 x or = x y Dilate translate x = e 6 b x 1.2 = x 2 = b or −4 10 x or = x a log x by 3 log x vertically 9 units by x the c 3a positive a + b + c (3a + b) 2c (a + c) e 2 5) 7) + + ln(x + ln(x 5) + ln(x + 1) ln(x 4) 8) −7. = x 5. x c = −7 = −4 ln(x 5) + ln(x + 1) ln(x + 4) ln(x + 2) 5 = x = e ln(x 12) ln(x 12 + ln(x + 2) ln x ln(x + 2) ln(x 2); 8 is is not not possible, hence possible, hence x = x = ln x ln(x 2) 2 9 a x = ± 10 a x = 15 1 b x = 2 b x = 112 5 c x = c 4x 3 years 15 is the initial number of video x = 2 e x = 6 sharers. x b 21 hours 11 b a 3x + y + 2y y c d 8 a c 23 hours Students’ x = x own answers 0.746 = 0.333 d b x = 1.35 d x = 2 12 a 13 a y x x = e 0.24 b x y log y c x = 1.66 d x = 2.05 2 y c y x practice 14 a x −4.64 x 3 1 = b x Mixed a + log b + log c b log a + log c log a 3 ln x b ln x 16 b 8 8 1 c 3 log a + 2 log b + 4 log c d log a + e log a + log b 15 a 24 16 a 52 b 5 b 2.8 2 1 log b log c 0.05 x days million 17 y = 15e 2 2 a log 12.5 b ln 250 c log 40 4 d 4 log Review 6 ln e f a 2 ( x − 1) in context x log 6) + 54 4 3 (2x 1 a 8.90 1 b 4 x g Scale factor of 6.31 times bigger 3 log 7 c 2 Add 1.3 y d 3 a d y 2x b + 2y e x + 2y 3x c (x + y) 40 times e Eastern a 6.8 bigger Sichuan was 40 times bigger. 2y 2 acidic b 2.8 c 6.2 1 4 a 5x + y b 1 + (x + 3y) −7 d Yes e 1 × 10 −8 − 3.98 × 10 4 c 2(3x + 4y 2) d 1 + 1 y ln x 7x 2 3 a f (x ) 137 dB b 6.3 times bigger ln 30 ; = 2 a 1 5 ln Domain of f is ; range of f is + E13.1 5 + Domain of 1 is f ; range of is f Y ou 3 (x 1 b g (x ) + ; Domain of 1 Domain of g g is ; range of g ; range of g is already know how to: ; 1 Student 2 a diagrams in DGS + 1 is should + 2) = 10 is units scale in 1 ln(x d 7 = 1.29 34 d = horizontally b ln(x d a y of 2.58 = 5 5 graph 3 and b (2b a c b the 0.55 b 4 1.30 = x is y-direction. 2 3 k direction. d a of 3 in 1 2 range 3 6 2.93 ; 4 2 9 7 a ≠ ln factor 1 x vertically Practice , 3 1 x 5 b is ln 6 ln x + 1 k 5 a of ln 3 7 2 x 5 b Reection Rotation in 90° x = −1 anticlockwise, center (3, Answers 2) 341 2 c Translation 2 units left and 6 units down, Reection in x e Reection in the f Rotation 90° = 0 or the line y y-axis = x +1 anticlockwise, center a = 110°, b = 70° 4 AC = 1 A F, B 4.5 cm, DE = 6 cm 3 M 5 ∆ ABC 1 E, C JK ≅ JF FK ≅ FK 2 I K, 4 S G (reexive N Q, O P V, L, T H ∆ DEF ≅ ∠SRX (alternate ∠PXQ ≅ ∠SXR (vertically ≅ XS (denition the X, U ≅ = CD, AC = CA ≅ a b No b AC (AAS ≅ CD or No c BE = 3 ∠BCA ≅ ∠ECD (vertically Hence they ET AD ≅ DT is are opposite congruent. (given) they are BD is = congruent. (denition ∠BDC ≅ is a the denition symmetric of because it = is of a rhombus. property. SSS of congruence. CPCTC. given 90° AB = = of 90° because because AC × of it is ∠CAX + ≅ ∠AXC ⇒ 2 ∠AXC ⇒ ∠AXC = = of the ≅ given. AX ∆ ACX 180° of an isosceles triangle. congruency. CPCTC. triangle ∠AXC = RHS of because ∆ABX ∠AXB denition because because ≅ the because ∠CAD is is isosceles. the angle bisector. (SAS). (CPCTC). because they lie on a straight line. 180° 90° (SSS) OA = OB because they are both radii. bisector) (denition of AM = BM OM is because M is the midpoint of AB perpendicular) common. Therefore they are congruent. rotating the pentagon by ∆OAM ≅ ∆OBM (SSS). (SAS) Hence By (AAS) common. Hence 3 from it because ∆DCA ≅ ∠AXB common. ∠ADC DC congruent. because ∠DCA CA Hence (ASA) 4 ≅ DA ∠BCA Therefore angles) (given) ED = ∠BAX (given) AD = ∆CDA ≅ = ∆BCE (SSS) (given) ∠DEC Hence c BC because DA ∠CEB ≅ ≅ Yes ASA) ∠BAC AT are 2 CE 2 angles) ∆TSU ∠BCE Yes triangles opposite midpoint) ∆WXV 2 d of angles) ∆ PRQ ≅ Practice a (SSS) 4 AB ∠DAC 1 congruent. W ∆ABC ∆ JKL are ∆ NOM ≅ ∆ GHI property) triangles J 1 ≅ square) circle) ∠PQX Practice R, of of the Hence D (denition (denition Hence PX Practice ≅ HF (0,1) 7 3 HK 6 d 6 or 144°, ∆CDE will line up ∠AMO ≅ ∠BMO with ∠AMO + ∠BMO = 180° because they lie on a straight line. ∆ABC ∆ 2 4 ∆ABD, ∆BFE, ∆DCA, ∆EDB, ∆CDF, ∆DEA, ∆FAC, ∆EFC, ∆BAE, × ∠AMO 180° ∆CBF, ∠AMO ∆BCE, = = 90° ∆AFD 5 a L 1 Practice 1 AB ≅ BM AC ≅ AM ≅ (denition AM (reexive the of midpoint) property) triangles ∆ABM and ≅ CD BO ≅ DO (denition of circle) OC (denition of circle) ≅ Hence, PQ ≅ ∆ACM are congruent. (SSS) Y AB AO 3 X (given) MC Hence, 2 3 (given) the QR triangles are L 2 congruent. b (SSS) 1 OX 2 ∠OXZ ≅ OY = (they ≅ QX ∠QXR = Hence, ∠ABC the = 90° triangles (denition are of ≅ ≅ congruent. ∠ACB AC (given) (∆ABC implies 3 OZ 4 Hence ≅ ≅ OA OC is ∆ABC Hence 5 AB AD ≅ ≅ ≅ (reexive AB AE Hence a circle in triangles (reexive of ≅ has a congruent. ≅ ∆OYZ (RHS) (CPCTC) ABCDE (properties line of a of symmetry regular perpendicular pentagon). Since K to is DE through equidistant ED, it lies of triangles of of on the KA, line they of are symmetry, equal and hence KC length. (SSS) Mixed property) (denition 34 2 YZ circle) are (denition the ∆OXZ property) (denition the BD to isosceles Practice circle) 1 BE tangent radius) common XZ reection Hence the isosceles) to OB to (RHS) B AO radii) (the altitude) 10 AB both 90° (reexive) ∠QXP c 4 = (given) perpendicular QX are ∠OYZ a No c Yes (only SA given) b No (only SSA given) d No (only SSA given) circle) are congruent. Answers (SSS) (AAS) is a c Review in context 1.1 y 1 a Since folding rectangle they b EG are is is is a equivalent mirror to image reection, of the other one and hence congruent. the full width of the page. EX is half the width of thepage. y = 4 log (2 x) 10 c 30° d Since (0.5, 0) GDZ is the empty space previously occupied by the x 0 triangle ∠EGD e 30° f Since GDE, ≅ the ∠DGZ GF is half = two triangles are congruent. 30° the width of the paper (the edge GE ) 1.1 d and EY is half the width of the paper, they are the y same length. 2 g GF ≅ EY ( by f, above) y = x ∠FGH h = ∠YED = 30° (by ∠GFH = 90° (since ABFG ∠EYD = 90° (since the Hence ∠EYD ≅ ∠GFH Hence ∠GFH = ∠EYD FH ≅ DY d and is fold a is e, − 4 above) (0, 0.5) rectangle) parallel to ABC ) x 0 (ASA) (CPCTC) E14.1 e Y ou 1 x < should already know how 1.1 to: 7 y 2 a 2x − 3 3x + 6 = 1.1 (1.5, 0) y x 0 ( 4, 0) (1, 0) 0 x 2 y = x + 3x − 4 f 1.1 y ( 1.5, 6.25) y b = √x − 5 1.1 0 x (5, 0) y 3 x = −3 6 ± (0.405, 0) Practice 0 1 x (0, 1) 1 a c x x < ≤ −2 or −0.4 x or > x 6 ≥ 5 b 1.5 ≤ d 4 x < x < ≤ 2 1.5 x y = 2e − 3 2 3 e < x < 3 2 2 a b h (t) > 9600 About 3 x (x + 4 x (12 6) 23 > x) m seconds 216; ≤ 24; x 0 > 12 m < cm; x ≤ (x + 2.54 6) m > or 18 cm 9.46 m ≤ x < 12 m 2 5 y = 0.005x 0.23x + 22 > 25; x > 56 years Answers 34 3 6 a h (t) > 0 b 3.56 d seconds y 6 7 x > 2.73 8 4.47 cm 5 cm × 4.47 cm × 2 cm 4 Practice x = 2 2 3 1 1 a x > 1 or 1 < x < 0 b 0 < x ≤ 2 4 y c 1 < x e 1.5 g 3 < < 4 < x x < < d −1 or x R f > 4 < < x x > 2) + 3 < < −1 −2 or or 1 x < < x (2.05, 0) −5 < 0 6 x 2 3 5 6 2R 1 = ⇒ > 1, R > 2 1 2 + ln(x − 1 5.09 1.5 h 1 a 1.57 0 2R 2 > x R 2 + y e R 1 1 3 b R > 7.48 2 2 x + y ≤ 1 e − 3 1 Practice 3 (0.099, 0) 1 y a x 4 3 2 1 8 1 2 3 4 5 6 1 6 2 y 4 2 y > x + 3x − = −3 3 1 2 ( 3.3, 0) (0.303, 0) f y x 6 2 4 4 2 8 6 2 (0, 1) 6 ( 1.5, y 3.25) x + 3 x − 3 < 4 6 2 ( x = 3 3, 0) 8 x 8 6 2 4 4 y b 2 (0, 6 10 12 1) 1.0 4 (1.5, 0.25) 0.5 (1, 0) 6 (2, 0) 0 x 1.0 2 1.0 2 a y < − x 2 − 4 x + 5 b y ≥ 0.5 x + 2x y ≤ − 1 0.5 x 2x 1.0 c y a i ≤ + 1 e − d 4 > y x 2 y ≤ −x + 3x − 2 2 2 3 1.5 f (x ) = x − 4 ii y > f ( x ) ii y > f ( x ) ii y < f ( x ) 1 2.0 (0, 2 2) b i f (x ) = (x − 1) + 3 3 2.5 2 c i f ( x ) = x 6x + 5 (x − 45) 3 2 4 a f (x ) = − + 3 2025 b c Domain 0 ≤ y ≤ {x f 0 ≤ x ≤ 90}, range {y 0 ≤ 3} (x ) y c 6 ( Practice 0.75, 5.13) 4 5 1 a 1 ≤ x ≤ 3 b x < 2 or x > ≤ 4 8 (0, 4) 4 c 3 ≤ x ≤ 4 d 10 ≤ x 2 y ≥ 4 − 3x − 2x 1 1 3 e 3 < x < f 2 2 1 g < 1 ( 0 3 2 0 < x ≤ 1.70 3 Student’s cm x 1.0 1 2 3 34 4 < (0.851, 0) 2.35, 0) 2.0 x 2 Answers own x < or 3 2 answers x > 1 Practice c 5 y 2 1 a x < 0.209; x > ( 4.79 b 6.32 < x < 0.317 c 2.19 ≤ x ≤ 0.687 x < 0.333 or x > (4.35, 0) 0 8 d 0.345, 0) 6 4 x 2 2 2 4 e 2.79 ≤ x ≤ 1.79 2 y < 2x − 8x − 3 6 f x < −0.414 g 0.290 h 9.12 < ≤ or x < x > 2.41 0.690 8 x or x ≥ −0.877 −1.18 or x > 0.425 10 2 i x j 0.209 a < ∆ = 0, < x < 4.79 hence only one root, x = −1. Since the graph above the x-axis except for this one value, 11) lies d entirely (2, 12 there y is 1.5 only b ∆ = solution, 0, hence f ( x ) only = 0 one for x root, = x −1. = 2. Since the graph 1.0 lies y entirely above or on the x-axis, the solution is x ∈ < log (x + 1) 10 0.5 c Since ∆ < 0, the quadratic has no roots. Since a > 0, its graph (0, 0) is always above the x-axis for all values of x. Hence x∈ x 2.0 d 1.0 1.0 Since ∆ < 0, the quadratic has no roots. Since a < 0, its graph 2.0 3.0 0.5 is always below the x-axis for all values of x. Hence x ∈ 1.0 Practice 1 6 1.5 a x < −1 or x > 1 b c x < −1 or x > 4 d 1 < x ≤ 4 y e x ≥ 3 or x < 2 10 2 1 e 0 < x < f x > 5 or x ≤ − 2 3 < x < 8 3 4 −1 6 3 About 17 (0, 5.14) 4 x − y Mixed 1 ≥ 2 e + 5 practice a x < −3 c x < −3.59 or e 0 x > 2 −1 b x ≤ −8.58 or d x > 0 < f 0.333 x ≥ 0.583 0 10 < x < or x > 2.09 0.286 or < x x < 8 6 4 x 2 −3 2 8 10 y y a 6 5 f 2 4 2 8 6 6 2 y > x − 4x + 2 4 4 y x 2 = x − 2 x + 4 > 2 −4 (3.41, 0) (0.586, 0) x 12 0 6 4 10 8 6 4 2 2 4 6 8 x 2 2 4 2 6 (0, 1) 2 (2, 2) 4 4 6 6 3 y b a 6 c 7 < < x < x < 1 b 5 x d < 8 −2 < x and < x > 12 2 6 (1.5, 4.5) 3 e 0 < x < 5.5 f x ≤ 4 or x ≥ 2 5 2 y ≥ −2x + 6x g x > 3 or x < −5 h 1 < x < 1 2 (3, 0) (0, 0) 2 4 36.2 meters 5 Between 11 6 4.6 < radius 7 1.66 < x x 0 4 2 4 6 and 30 tourists 2 cm < 9.7 cm; 6.8 cm < height < 29.8 cm 4 in < 6.16 in 6 Review 1, 2 in context Student’s own answers. Answers 34 5 d E15.1 Y ou 1 should already know how a Song to: A B 2 9 1980 17 Song 1 10 1980 18 e 8 1990 17 A B 10 1980 17 8 1990 18 7 1990 17 Practice 5 1 b 17 1 1 1 P (B | A) = B 36 32 2 3 a 4 b 52 36 c 169 1 221 P (B A 1 | A ) = 36 2 35 B 1 15 3 a P ( A) b = P(A ∪ B ) P (B ) 36 = 1 1 = 1 + = 72 27 72 36 1 B 4 36 U 1 A 2 A B 35 26 7 21 B 36 P (B ∴ A) = P (B independent A ) = P(B ) events 5 5 2 5 P (B a A ) = B 9 9 3 5 P (B A A ) = 5 9 4 B P (B ) = P (A ∩ B ) + P (A′ ∩ 9 3 = 5 B = + 9 5 2 9 9 9 2 A b 5 4 B A 9 B P (B ∴ A) = P (B independent A ) = P (B ) events 3 4 4 B 9 P (B A) = c 9 5 5 A P (B A ) = 10 9 A B 5 B 2 9 P (B ) B 9 5 A 10 4 B 9 P (B The 34 6 Answers A) ≠ P (B events are A ) not ≠ P (B ) independent. = 5 + 9 5 1 = 18 2 B ) 4 6 17 B 5 10 a ii 35 6 P( B 7 A) b iii 35 35 7 13 9 A 1 17 19 i i ii iii = 4 B 18 17 19 10 10 7 c 28 1 B 2 6 1 A 7 P( B A ) Practice 3 = 2 1 a 1 Male (M ) Female (F ) Total B 2 Professional The events are not P (B A) 5 12 17 5 6 11 10 18 28 Amateur(A) 5 5 (P ) independent. = 9 Total 6 P (B A ) = , therefore not independent events. 9 5 b i P (M P ) 10 5 = ii P (M A) = iii P (M ) = 5 6 P (B A) 17 = 28 11 11 c No they are not independent events 6 P (B A ) = , therefore not independent events. 2 11 7 8 = soccer P (B A) P (B A ) = 65%, P (Y X ) = 0.8 P (Y X ) No soccer Total 90% = therefore not independent 0.8 ∴ P (Y ∴ independent X ) = P (Y X ) = P (Y Left 10 30 40 Right 15 45 60 Total 25 75 100 events. ) 10 P (L S ) = events 25 Practice 30 2 P ( L 11 1 = 75 11 a b 26 2 NS ) 2 32 P ( L ) = They are 5 a K independent events. C 3 20 12 Yes, because P (F and S ) = P (F ) × P (S ) 14 Practice 4 1 1 a P( LS operation) = P ( LS No operation) = P ( LS ) = 4 9 The i P( K ) are independent events the claim is not valid. 12 32 b results = ii P (C K ) = b 1 32 50 LS 9 12 26 iii P (C ) = iv P (K C ) = 26 50 1 O 4 3 a 8 LS 9 A D 1 7 5 10 LS 9 3 O 4 8 8 LS 9 5 12 b i P ( A) = ii P (D A) = It 12 30 is evident P ( LS P (D ∪ A) = iv P (D 9 15 a b 25 the tree diagram ( LS operation) = ∩ A D ∪ A) c = Student’s own answer with justication. 22 30 4 from operation) 5 22 iii No 4 c 25 9 Answers 34 7 2 a T Mixed Total T 1 G 10 15 practice a 44 25 O 99 40 G 30 10 40 40 25 65 99 O A 45 Total 100 15 B 99 b The events are not independent. 45 c Student’s own O answer. 99 40 3 a i P (E ) iii P (L v P (E vii P (E′ = 0.4 ii P (L iv P (E E ) vi P (E′ ∩ viii P (L) = = 0.8 39 100 99 A E ∩ ) = L ) 0.4 = 0.08 ∩ L) L) = A 0.32 = 0.24 15 B b No, ∩ L ) because = 0.36 the conditional 0.56 probabilities are 99 dierent. 45 O 99 15 40 Practice 5 100 99 B 1 A a 14 B A W 23 10 99 8 3750 25 9900 55 40 = b c d 66 99 99 6 12 1 2 10 2 a b c 13 i P (A ) = ii P (W ) = 10 P (A W ) d 3 5 1 e 3 g f 13 51 51 iii 5 18 33 b 13 2 4 10 = iv P (W A) 18 = 3 2 a 33 I 3 8 v P (W A ) = S 4 18 5 1 I A c A 3 W 10 8 18 W 23 10 33 33 18 51 1 I 3 1 S 5 2 I 3 12 12 2 4 b a c 2 8 × b = 70 30 5 P (M ) does therefore not not equal P (M FT ) does not equal P (M FT ), c independent. 3 P( I ∴ 15 S ) not ≠ P (I S ) independent 4 3 a 88% 4 b a S 0.2 12 c No, the from the tree diagram the second branches are not R 0.5 same. 0.8 4 S 14 14 a b 70 30 S c Yes they are independent as 0.8 0.5 16 P (M L) = 64 = 30 P (M L ) R = 120 0.2 S b Th Th 34 8 Answers 2: 3: = 0.1 P (R ) P (R ∩ S ) = 0.5 P (S ) = 0.1 = 0.5 P (S R) = 0.2 P (S R = 0.8 ) P (R + ∩ S ) ≠ P (R ) × P (S ) 0.4 ∴ Not independent ∴ Not independent 5 a Review T in context T 45 B 19 29 1 48 a i P (D ) 200 11 B 11 1 9 = = ii P (N ) = 2 40 1 22 iii P (D N ) iv P (D N ) 10 30 40 = = 20 100 70 b They are not independent from Theorem 3. 29 30 b c d Not independent, by Th 3 2 a T 48 70 6 7 35 = 0.98 a B 0.01 H 0.02 B 4 4 T 2 T 0.05 0.99 4 8 b B 10 6 i ii iii 14 0.95 T 14 14 b 4 6 iv 14 3 14 4 12 The events 14 0.9503 Smoker (A) Non-smoker (A ) 14 Cancer B ) = independent. ix (B ) 1763 981 2744 73 237 124 019 197 256 75 000 125 000 200 000 4 4 P (H 0.9405 are 4 4 viii 14 c + vi 14 vii 0.0098 8 v = P (H B ) = 8 6 (B ) 4 P (B H ) = P (B H 8 7 ) = 6 a 1763 Should have Should not have a Total P (B A) = 75000 dress code dress code 981 b Middle school 15 30 P (B A ) = 45 124 High school Total 40 80 120 55 110 165 c d They are not Students’ 019 independent own from Theorem 2 answer 10 5 b Theorem a 15 and 0.69 b P(A) = 0.01 c P(B ) = code ) = P (MS ) × P (dress The events are not independent. code) 55 × 165 Theorem P (MS = 330 Dress 45 = 165 A) 2 b P (MS P(B 165 3 DC ) = P (MS DC ) 30 15 = 55 110 Therefore they both work. Answers 34 9 Index cosine A r ule 183–4, application A4 paper additive 203–4 systems ambiguous amplitude case of a formula 3 for areas the sine sinusoidal Angle-Side-Angle angular CPCTC r ule Congr uence displacement 243–5 function 192, cuboids 168–176 135–7 (ASA/AAS) 269, 277 D 127 data of a parallelogram 76–7 188 dispersion area of a segment area of a triangle area of a triangle 82 184–9 normal formula 185, sine of an and sine equilateral cosine and cosine r ules triangle 189–94, r ules, distribution problems, of a applying logarithm series 146, decimal exponents decimal number 218, 226, 170, 229, 211, cur ve binar y 111 3–17 86 180 221–2, 229 16–18 functions functions space formula dividing space higher 213 229 the 168–75 172, 180 175–9 diagonals nding 211, 221–2, 167–8 distance face numbers 9–10 231 describing number 171, 213, dimensions bases, 5, 32 164 B logarithm 105–6 111 151, rational a 98, system functions logarithmic of 94 114–116 195–9 dilation asymptotes and 188 diagonals arithmetic growth 199 decomposing argument 86–7, 199 decay area 77–87 188 mean bell 199 273 183–4 area base 189–94 195–9 170 midpoint dimensional planes 169, section formula 176, space 180 179–80 180 C change of circles base formula 111 space 124–5 area of radian a dispersion segment measure circle column diagonals 188 and 125–34, vectors distance the unit dot 178, 180 170–1, 180 77–87 formula product 68, 172, 180 73 142 56–7, 73 E common ratio, components, composition of of compounded conditional 153–4 vectors probability decisions representing with notation 1 Theorem 2 302, 312 Theorem 3 302, 312 is equations exponential functions from 302, probability 301, 312 309–12 decimal probabilities 264–5, for 273, 305–9 exponents 98, exponents probability? 98–102, 301–4 face diagonals four dimensions 170 277 congr uence 269, 179–80 277 163 277 congr uent triangles exponents 97–102, 106 265–73 of a sinusoidal 266 function 135–7 270 function using congr uence to prove operations results 21–2, 35–6 273–6 decomposing similarity to prove other results Index functions 32–3 276–7 doing 3 5 0 22 other functions using functions 105–6 97–8, F frequency sign logarithmic 205 fractional fractional establishing shapes to 121 203 exponents 312 fractals CPCTC exponential inverses 109, 202, 302 conditional conditions axiom 273 exponential 299–300 conditional Theorem congr uence Euclid 29–32 117 probabilities mathematical what 59 functions interest conditional making r and undoing 50–1 106 203–5 exponential function inverse functions logarithmic modelling and sinusoidal of logarithmic dilation 44–50, 51 202–12, compositions 38–44, 37–8, functions reversible types 42, functions functions rational 202–5 22–9 functions using one-to-one onto functions operations from 213 of 29–32 51 51 of reection 211, 134–41, 44–50 translation 142 logarithms 37–43 base 111, change of 211, 111, functions 206–7, functions 203–5 209, 213 205–10 logarithmic 210–12, 213 213 108–9, argument functions 213 functions changes 213 logarithmic logarithmic transformations irreversible to logarithmic proper ties 216–31 functions of 202–3, 213 exponential graphs functions functions 211, 109–14 121 121 of base formula 111, 121, 257, 261 G creating Gallivan, Gauss’s Britney method generalizations proving series 162, grad/gradian of of 164 of logarithms 249–54, logarithms 117–21, r ule proving generalizations using 125 zero 206–7, 209, 251, r ule r ule 261 251, 251, 251, 255–8 261 261 logarithms r ule 261 121 261 r ule unitar y 164 251, product quotient logarithmic functions graphs 154, geometric series graphs 146, 255–8 250–4 natural power 250–4 generalizations geometric innite laws 204 149 generalizations to solve equations 114–17, 258–61 261 213 sinusoidal M functions growth and 134–41 decay problems magnitude, 114–116 mapping Mayan vectors diagram number 60–61 49 system 11–12 H mean hexadecimal hieroglyphic midpoint, 17 compositions 3–14 asymptote equation 226, 218, 176, 180 multiple horizontal dilations horizontal line horizontal shift horizontal translation horizontal translations 136, of multiplication 51 29–32 transformations, order 254 37, of functions 231 229 test nding modelling number system, horizontal 82 229 tables, dierent bases 16 142 of a sinusoidal function 135–7 N hyperbolas 254 Napier, 219 John non-linear 118, 251, inequalities algebraic solutions 256 282–3, to 297 non-linear inequalities 291–6 I indices innite 97–8, inter net inverse 102–5, geometric search ranking functions exponential inverse isosceles of a 106 series 42, rational 164 255 44–50, functions triangle 162, 51 non-linear inequalities in one variable non-linear inequalities in two variables function 274 a quadratic inequality algebraically solving a quadratic inequality graphically solving non-linear graphically 230–1 288–91 solving 205 theorem 283–8 normal number distribution systems binar y in in two variables 297 86–7, 94 16–18 dierent bases 3–12 K performing Koch snowake operations 12–16 163 O L one-to-one onto Leibniz, Gottfried of symmetr y 37–8, 38–44, 51 51 6 ordered line functions functions pairs 41 42 Index 297 297 2–3 numbers numbers equalities 289, 292, 284, 3 51 scalars P 61, scalar paper folding formula parallelograms, area of per pendicular height per pendicular vectors phase place shift 135, value planes 169, versus 57, numbers positive real product 121 111, r ule 101, logarithms 106 in real-life 250–1 order graphs of logarithmic functions 157 206 theorem 170, Pythagorean identity Pythagorean triples Pythagorean quadr uples 192 (SAS) (SSS) 269, 269, 277 277 199 shift 134–41, 136, transformations 135, 136, 142 142 141, 142 142 132 167–8 face 171 164 159–63 195–9 shift distance 171 164 162, 163 functions describing 239 73 189–94 SOHCAHTOA space 164 Congr uence 189, of phase 65, 155–9 Triangle sinusoidal 151, Congr uence 183–4, formula 250–1 logarithms scheme Pythagoras’ series r ule vector 154, series fractions horizontal of of and application 99, 255 proper ties series sine 146, geometric Sier pinski 121 numbers of 91–4 146, series Side-Side-Side 73 a 164 series Side-Angle-Side 255 proving pyramid innite population positive proving geometric 4 of 177–8 146 145–55, arithmetic 142 117, vectors r ule 73 growth equation power series 69, formula sequences 79–80 population sample 188 180 populations position section 185 136, system 204 73 multiplication space diagonals nding higher 168–75 formula the 172, 180 170 midpoint dimensional planes 169, section formula 176, 180 space 179–80 180 Q quadrants quotient 128–9 r ule proving of space logarithms 250–1 diagonals special 255 triangles standard 178, 170, dierent 180 132 deviation calculating 180 171, from 76–7, 94–5 summar y formulae for statistics dierent 89–90 pur poses R sample radians 125–34, angles ultimate 142 sum 127 radian radicals measures 97–8, versus of a population measure sequence of 91–4 dispersion 77–87 147 126 102–5, 106 T radicands Ratio 104, identity rational 106 239 functions dilation inverse 221–2, of a transforming translation exponential logarithmic 230–1 rational domain rational and range functions 226 224–9 229 217, hyperbola 219 219 vectors tree logarithmic reversible Right and functions 211, irreversible 213 changes Angle-Hypotenuse-Side (RHS) 269, trial 44 Congr uence 277 211–12 210–13 224–9 functions 141, 142 translation rational reection functions functions functions sinusoidal logarithmic functions rectangular 198 transformation 229 function, reciprocal 231 rational function parent theodolite 216–24, 63, diagrams and 211, 213 229 73 301–11 improvement triangles area functions functions 110–111 183–4 184–9 area of a area of an triangle formula 185, 199 equilateral triangle 188 S CPCTC samples establishing 79 sample versus 3 5 2 273, population Index 91–4 277 congr uent triangles 265–73 87–91 triangular numbers trigonometr y ambiguous cosine case r ule sine 239, 183–4, with per pendicular position 189–99 identity identity r ule operations 242–6 183–4, Pythagorean ratio 147 233–4 239, vectors resultants 246 scalar 246 63, 189–99 equations trigonometric identities 234–8 235, 238–42, 246 63, addition vector geometr y zero vectors diagrams ver tical 62–70 69, 73 73 73 vector Venn 57, multiplication translations trigonometric vectors vectors law 57, of a vector 65, 73 73 63–64 70–2 73 305–310 asymptote 218, 231 U equation unbiased unit estimate circle unitar y volume 92 226, 229 diagonal 171 126–133 r ule of logarithms 250–1 X x y plane 169 V vectors 54–60 Z column dot vectors product equal 68, 56–7, 73 components magnitude 73 60–2, 59, 73 zero r ule zero vectors of logarithms 57, 250–1 73 73 Index 3 53 MYP Mathematics A Fully integrated students An to inquir y-based learners to exploring This ● text learners extensive Explore Fully that the Key ● clearly and mapped Combine to combined practice the of the confidently this comprehensive understanding with links essential to of Global knowledge book empowers contexts and skills equips while mathematics. step into IB Diploma meanings of mathematical Mathematics, topics the MYP curriculum integrated the MYP with concepts and learners latest MYP approach principles and with through of Inquir y, content Global contexts, ATL for assessment assessment with mathematical Statements with guidance objectives essential practice. available: 0 19 835618 9 How 1 to get in approach 4&5 mathematics. activities prepare to mathematical 978 engaged practice Related Effectively Also curriculum, and applications wider suppor t is and wider inquir y-based ● MYP deep approach acquire the the a will Enable with ● with develop concept-based contact: web www.oxfordsecondary.com/ib email schools.enquiries.uk@oup.com tel +44 (0)1536 452620 fax +44 (0)1865 313472 Extended