NEW CENTURY MATHS Advanced 9 For the australian curriculum NSW Stages 5.2/5.3 Sample Chapter NEW CENTURY MATHS 9 ADVANCED NSW STAGES 5.2/5.3 ISBN: 978 0 17 019308 5 Klaas Bootsma David Badger Sarah Hamper Robert Yen Series Editor Customer Service: 1300 790 853 www.nelsonsecondary.com.au Preface First published in 1996, New Century Maths Advanced 9 Stages 5.2/5.3 has now been completely rewritten to reflect the spirit of the new Australian curriculum and the NSW syllabus. For Years 9 and 10, we publish two levels of mathematics books: t New Century Maths Stages 5.1/5.2 t New Century Maths Advanced Stages 5.2/5.3 The NSW mathematics syllabus describes Stage 5 (Years 9–10) as a continuum with content classified into three sub-stages, Stage 5.1, Stage 5.2 and Stage 5.3, with each sub-stage including the content of the previous sub-stage. This book has been designed for students and classes progressing along Stages 5.2 or 5.3 of the continuum. We have retained those familiar features that have made New Century Maths a leading series: clear worked examples, graded exercises, multiple-choice questions, Investigation, Technology, Mental skills, SkillCheck pre-chapter exercise, Power Plus extension exercise, Language of Maths, Topic overview with mind map, glossary, video tutorials and worksheets. New features include: t t t t t t )PNFXPSLTIFFUT 8PSLFETPMVUJPOTUPTFMFDUFERVFTUJPOT GeoGebra activities in our Technology sections $IBQUFSPVUMJOFTTIPXJOHDPWFSBHFPGUIF8PSLJOH.BUIFNBUJDBMMZQSPGJDJFODJFT NelsonNet student and teacher websites of print and multimedia resources NelsonNetBook digital version of this book with interactive features We always aim to write textbooks to provide flexibility for teachers to plan and teach for a variety of pathways. We thank our families and teaching colleagues for their continued support and patience, and editors Anna Pang and Alan Stewart for transforming our manuscript into this fine text. Finally, we wish all teachers and students using this book every success in embracing the new Australian mathematics curriculum. About the authors Klaas Bootsma XBTIFBEUFBDIFSPGNBUIFNBUJDTBU"NCBSWBMF)JHI4DIPPMJO$BNQCFMMUPXOBOE IBTUBVHIUBU-VSOFBBOE(SBOUIBNIJHITDIPPMT)FXBTBTFOJPS)4$FYBNJOFSBOEIBTXPSLFEPO UIF)4$"EWJDF-JOFBOE4DIPPM$FSUJGJDBUFNBSLJOH,MBBTIBTXJEFFYQFSJFODFUFBDIJOHBMMUZQFTPG students, and his interests are in curriculum and the use of technology (ICT) in learning. David Badger is principal of Toongabbie Christian School, was deputy principal at Mt Annan Christian $PMMFHFBOEIFBEUFBDIFSPGNBUIFNBUJDTBU&BHMF7BMF)JHI4DIPPMJO$BNQCFMMUPXO)FIBTCFFO JOWPMWFEJO)4$BOE4DIPPM$FSUJGJDBUFNBSLJOHBOEIBTXPSLFEPOUIF)4$"EWJDF-JOF%BWJET passion is to make mathematics interesting, practical and accessible to all students. Sarah Hamper teaches at Abbotsleigh School in Wahroonga and has taught at Meriden and Tara "OHMJDBOTDIPPMT4IFIBTBOJOUFSFTUJOHJGUFEBOEUBMFOUFE ("5 TUVEFOUTBOEHJSMTFEVDBUJPO4BSBIT expertise is in using modelling, problem solving and ICT for the effective learning of mathematics, and she has presented workshops for MANSW and nationally. Series editor Robert Yen has UBVHIUBU)VSMTUPOF"HSJDVMUVSBM &BHMF7BMFBOE"NCBSWBMFIJHITDIPPMT JOTPVUIXFTU4ZEOFZ)FDPXSPUFNew Century Maths Essentials 9–10 and Mathematics General 2, writes and presents for MANSW, and has co-edited its journal, Reflections)FOPXXPSLTGPS$FOHBHF Learning as an associate publisher. SAMPLE CHAPTER Contributing author Megan Boltze wrote and edited many of the NelsonNet print resources (blackline masters) and is head UFBDIFSPGNBUIFNBUJDTBU"TIDSPGU)JHI4DIPPM 9780170193085 iii Contents Preface About the authors Curriculum grids User’s guide Acknowledgements iii iii viii xii xiv Mental skills 2A: Squaring a number ending in 5, 1 or 9 2-05 Simple interest 2-06 Ratios and rates 2-07 Converting rates Mental skills 2B: Estimating square roots Power plus Chapter 2 review 69 69 71 Chapter 3: Products and factors 74 9NA211 8NA188 9NA208 * ¼ STAGE 5.3 Chapter 1: Pythagoras’ theorem and surds 9MG222 9MG222 10ANA264 10ANA264 10ANA264 10ANA264 9MG222 9MG222 9MG222 SkillCheck 1-01 Finding the hypotenuse 1-02 Finding a shorter side 1-03 Surds and irrational numbers* pffiffiffi Investigation: Proof that 2 is irrational 1-04 Simplifying surds* Mental skills 1A: Multiplying and dividing by a power of 10 Investigation: A formula for calculating square roots 1-05 Adding and subtracting surds* 1-06 Multiplying and dividing surds* 1-07 Pythagoras’ theorem problems 1-08 Testing for right-angled triangles Mental skills 1B: Multiplying and dividing by a multiple of 10 1-09 Pythagorean triads Power plus Chapter 1 review 2 4 4 10 15 16 18 NSW 8NA187 8NA189 iv SkillCheck 2-01 Terminating and recurring decimals 2-02 Converting recurring decimals to fractions* 2-03 Operations with percentages 2-04 Percentages and money 8NA192 10NA232 10NA232 20 21 22 9NA213 8NA191 9NA213 23 25 10NA233 31 34 34 37 39 Chapter 2: Working with numbers 42 8NA184 8NA192 10NA233 10NA233 10ANA269 44 10ANA269 45 SkillCheck 3-01 Adding and subtracting terms 3-02 Multiplying and dividing terms 3-03 Adding and subtracting algebraic fractions 3-04 Multiplying and dividing algebraic fractions Mental skills 3A: Multiplying and dividing by 5, 15, 25 and 50 3-05 Expanding expressions 3-06 Factorising expressions 3-07 Expanding binomial products Investigation: Expanding perfect squares 3-08 Perfect squares* Investigation: Squaring a number ending in 5 Mental skills 3B: Multiplying by 9, 11, 99 and 101 Investigation: Expanding sums by differences 3-09 Difference of two squares* 3-10 Mixed expansions* 3-11 Factorising special binomial products* Investigation: Factorising quadratic expressions 3-12 Factorising quadratic expressions* Investigation: Factorising quadratic trinomials by grouping in pairs 3-13 Factorising quadratic expressions of the form ax2 þ bx þ c* SAMPLE CHAPTER 47 48 53 10ANA269 57 59 62 68 76 77 79 82 84 85 87 90 93 97 97 100 100 101 101 103 104 106 107 110 110 9780170193085 N E W C E N T U R Y M AT H S A D V A N C E D for the A 10ANA269 NSW 3-14 Mixed factorisations* 3-15 Factorising algebraic fractions* Power plus Chapter 3 review 114 116 118 119 9NA209 122 9NA209 Chapter 4: Trigonometry 126 9NA210 9NA210 Mixed revision 1 9MG223 9MG223 9MG223 9MG223 9MG224 9MG224 9MG224 10MG245 10MG245 10MG245 SkillCheck 128 4-01 The sides of a rightangled triangle 129 4-02 The trigonometric ratios 132 4-03 Similar right-angled triangles 135 Technology: Similar rightangled triangles 138 4-04 Trigonometry on a calculator 140 Mental skills 4: Estimating answers 143 4-05 Finding an unknown side 144 Investigation: Calculating the height of an object 150 4-06 Finding more unknown sides 151 Investigation: Finding an angle, given a trigonometric ratio 155 4-07 Finding an unknown angle 156 4-08 Angles of elevation and depression 161 4-09 Bearings 165 Investigation: Compass walks 169 4-10 Problems involving bearings 169 Power plus 172 Chapter 4 review 174 Chapter 5: Indices 9NA212 9NA212 9NA212 9NA212 9780170193085 178 SkillCheck Investigation: Multiplying and dividing terms with powers 5-01 Multiplying and dividing terms with the same base Investigation: Powers of powers 5-02 Power of a power 5-03 Powers of products and quotients Investigation: The power of zero 5-04 The zero index Mental skills 5: Adding or multiplying in any order 180 10ANA264 10ANA264 NSW Investigation: Negative powers Technology: Negative powers 5-05 Negative indices 5-06 Fractional indices n1* 190 191 193 197 5-07 Fractional indices mn * 5-08 Summary of the index laws 5-09 Significant figures 5-10 Scientific notation 5-11 Scientific notation on a calculator Investigation: A lifetime of heartbeats Power plus Chapter 5 review 199 202 204 206 218 220 223 Technology: Sketching parallelograms and rectangles 6-02 Quadrilateral geometry 228 230 166 7MG 165, 166 NSW NSW NSW NSW Investigation: Angle sum of a polygon 6-03 Angle sum of a polygon Investigation: Exterior angle sum of a convex polygon 6-04 Exterior angle sum of a convex polygon Mental skills 6: Dividing decimals Power plus Chapter 6 review Chapter 7: Equations 8NA194 8NA194, 9NA215 8NA194 181 184 184 10NA240 SkillCheck 7-01 Equations with variables on both sides 7-02 Equations with brackets 7-03 Equation problems 7-04 Equations with algebraic fractions Mental skills 7A: Fraction of a quantity Technology: Solving equations on a graphics calculator Investigation: Solving x2 ¼ c 7-05 Simple quadratic equations ax2 ¼ c SAMPLE CHAPTER 190 213 214 215 SkillCheck 6-01 Triangle geometry 7MG 165, 9 210 Chapter 6: Geometry 180 186 188 188 ustralian Curriculum 10NA241 238 239 243 244 246 247 248 252 254 254 257 259 263 266 267 267 268 v Contents NSW NSW 10NA234, 235 NSW Investigation: Solving x3 ¼ c 7-06 Simple cubic equations ax3 ¼ c* 7-07 Equations and formulas 270 270 272 7-08 Changing the subject of a formula* Mental skills 7B: Percentage of a quantity Power plus Chapter 7 review 275 277 278 279 Mixed revision 2 Chapter 8: Earning money NSW NSW NSW NSW NSW NSW NSW NSW NSW 9SP227 284 288 SkillCheck 8-01 Wages and salaries 8-02 Overtime pay Technology: Calculating incomes 8-03 Commission, piecework and leave loading 8-04 Income tax Technology: Online income tax calculators Mental skills 8: Percentage increase and decrease 8-05 PAYG tax and net pay Technology: Online PAYG tax calculator Power plus Chapter 8 review 290 290 295 299 7SP171, 8SP207 9SP282, 228 9MG219 NSW 9MG216 8MG196 300 306 9MG216 308 9MG218 309 310 9MG217 8MG198 313 314 315 9SP282 9SP283 8SP284, 9SP228 vi 320 321 10AMG271 330 331 338 340 344 347 356 358 359 366 368 374 376 379 383 384 391 398 399 401 406 407 409 410 413 419 421 Mixed revision 3 426 Chapter 11: Coordinate geometry and graphs 430 9NA214 349 356 SkillCheck 10-01 Metric units 10-02 Limits of accuracy of measuring instruments 10-03 Perimeters and areas of composite shapes 10-04 Areas of quadrilaterals Mental skills 10A: Finding 10%, 20% and 5% 10-05 Circumferences and areas of circular shapes 10-06 Surface area of a prism Investigation: Surface area of a cylinder 10-07 Surface area of a cylinder 10-08 Volumes of prisms and cylinders Investigation: Volume vs surface area Technology: Drawing prisms and cylinders Mental skills 10B: Finding 15%, 212%, 25% and 1212% Technology: Approximating the volume of a pyramid 10-09 Volumes of pyramids and cones* Power plus Chapter 10 review SAMPLE CHAPTER 348 352 353 Chapter 10: Surface Area and Volume 364 Chapter 9: Investigating data 318 SkillCheck 9-01 The mean, median, mode and range Technology: Most valuable player 9-02 Histograms and stem-and-leaf plots Technology: Histograms 9-03 The shape of a distribution 9-04 Comparing data sets Technology: Comparing relative humidities Mental skills 9: Finding a percentage of a multiple of 10 9-05 Sampling and types of data Investigation: Australian Bureau of Statistics 9-06 Bias and questionnaires Investigation: Media reports of surveys Investigation: Year 9 student survey Power plus Chapter 9 review SkillCheck 11-01 The length of an interval 432 433 9780170193085 N E W C E N T U R Y M AT H S A D V A N C E D for the A 9NA294 9NA294 9NA215 NSW NSW 8NA194 9NA208 9NA296 9NA296 Technology: The length of an interval Investigation: The midpoint of an interval Technology: The midpoint of an interval 11-02 The midpoint of an interval 11-03 The gradient of a line Technology: The gradient of collinear points 11-04 Graphing linear equations Technology: Graphing linear equations Mental skills 11: Divisibility tests Investigation: Comparing gradients and y-intercepts 11-05 The gradient-intercept formula y ¼ mx þ b 11-06 Finding the equation of a line 11-07 Solving linear equations graphically 11-08 Direct proportion Investigation: Graphing y ¼ x2 and y ¼ ax2 Technology: Graphing y ¼ ax2 Investigation: Graphing y ¼ ax2 þ c 11-09 Graphing quadratic equations 11-10 Graphing circles Power plus Chapter 11 review Chapter 12: Probability 8SP204 9SP226 9SP226 9SP226 SkillCheck 12-01 Probability 12-02 Relative frequency Technology: Throwing a coin 12-03 Venn diagrams 12-04 Two-way tables Investigation: Using two-way tables Mental skills 12: The unitary method with percentages Investigation: Are the Lotto numbers equally likely? 9SP225 437 ustralian Curriculum 12-05 Two-step experiments Power plus Chapter 12 review 511 517 518 438 439 440 444 Chapter 13: Congruent and similar figures 449 8MG201 450 10MG243 456 10MG243 457 458 459 9MG220 462 464 465 9MG220, 221 468 469 9MG221 470 471 475 479 480 484 486 487 492 497 500 506 509 10MG244 9MG220 10MG244 SkillCheck Investigation: Congruent triangles 13-01 Tests for congruent triangles 13-02 Congruent triangle proofs 13-03 Using congruence to prove geometrical properties Investigation: Same shape, different size 13-04 Similar figures Mental skills 13: Simplifying fractions and ratios Investigation: Properties of similar figures 13-05 Properties of similar figures Investigation: Are all shapes similar? 13-06 Scale diagrams Investigation: Floor plans Investigation: Areas of similar figures Technology: Areas of similar figures 13-07 Areas of similar figures* Investigation: Similar triangles 13-08 Tests for similar triangles 13-09 Similar triangle proofs* Power plus Chapter 13 review 509 511 522 524 525 526 531 536 539 540 547 548 549 554 554 559 560 561 563 566 567 571 576 577 Mixed revision 4 582 General revision Glossary Answers Index 586 592 606 00 SAMPLE CHAPTER 9780170193085 9 vii Curriculum grid: Australian curriculum Strand and substrand New Century Maths Advanced 9 Stages 5.2/5.3 chapter New Century Maths Advanced 10 Stages 5.2/5.3 chapter NUMBER AND ALGEBRA Real numbers 1 2 5 11 Pythagoras’ theorem and surds Working with numbers Indices Coordinate geometry and graphs 1 Surds 7 Graphs 8 Equations and logarithms Money and financial mathematics 2 Working with numbers 2 Interest and depreciation Patterns and algebra 3 Products and factors 5 Indices 7 Equations 5 Products and factors 8 Equations and logarithms 14 Polynomials Linear and non-linear relationships 7 Equations 11 Coordinate geometry and graphs 3 5 7 8 10 11 Coordinate geometry Products and factors Graphs Equations and logarithms Simultaneous equations Quadratic equations and the parabola 14 Polynomials MEASUREMENT AND GEOMETRY Using units of measurement 10 Surface area and volume Geometric reasoning 6 Geometry 13 Congruent and similar figures Pythagoras and trigonometry 1 Pythagoras’ theorem and surds 4 Trigonometry 4 Surface area and volume 13 Geometry 15 Circle geometry 9 Trigonometry STATISTICS AND PROBABILITY Chance 12 Probability Data representation and interpretation 9 Investigating data 12 Probability 6 Investigating data SAMPLE CHAPTER viii 9780170193085 Curriculum grid: NSW syllabus Strand and substrand New Century Maths Advanced 9 Stages 5.2/5.3 chapter New Century Maths Advanced 10 Stages 5.2/5.3 chapter NUMBER AND ALGEBRA Financial mathematics (Stage 5.2) 2 Working with numbers 8 Earning money 2 Interest and depreciation Indices (Stage 5.2) 5 Indices 5 Products and factors Linear relationships (Stages 5.2, 5.3) 7 Equations 11 Coordinate geometry and graphs Non-linear relationships (Stages 5.2, 5.3) 7 Equations 11 Coordinate geometry and graphs Ratios and rates (Stages 5.2, 5.3) 2 Working with numbers 11 Coordinate geometry and graphs Algebraic techniques (Stages 5.2, 5.3) 3 Products and factors Equations (Stages 5.2, 5.3) 7 Equations Surds and indices (Stage 5.3) 1 Pythagoras’ theorem and surds 5 Indices Polynomials (Stage 5.3) 3 Coordinate geometry 3 Coordinate geometry 7 Graphs 11 Quadratic equations and the parabola 7 Graphs 5 Products and factors 8 Equations and logarithms 10 Simultaneous equations 11 Quadratic equations and the parabola 5 Products and factors 14 Polynomials Logarithms (Stage 5.3) 8 Equations and logarithms Functions and other graphs (Stage 5.3) 16 Functions MEASUREMENT AND GEOMETRY Area and surface area (Stages 5.2, 5.3) 10 Surface area and volume Numbers of any magnitude (Stage 5.1) 5 Indices 10 Surface area and volume Right-angled triangles (Trigonometry) (Stages 5.2, 5.3) 1 Pythagoras’ theorem and surds 4 Trigonometry Properties of geometrical figures (Stages 5.2, 5.3) 6 Geometry 13 Congruent and similar figures Volume (Stages 5.2, 5.3) 10 Surface area and volume Trigonometry and Pythagoras’ theorem (Stage 5.3) 4 Surface area and volume 9 Trigonometry 4 Surface area and volume 13 Geometry 4 Surface area and volume 9 Trigonometry Circle geometry (Stage 5.3) 15 Circle geometry STATISTICS AND PROBABILITY Single variable data analysis (Stages 5.2, 5.3) 9 Investigating data 6 Investigating data SAMPLE CHAPTER Probability (Stages 5.1, 5.2) Double variable data analysis (Stages 5.2, 5.3) 9780170193085 12 Probability 12 Probability 6 Investigating data ix Curriculum grid: Year 9 content descriptions This is an extract from the Australian Curriculum. Content description New Century Maths Advanced 9 Stages 5.2/5.3 chapter NUMBER AND ALGEBRA Real numbers ACMNA208: Solve problems involving direct proportion. Explore the relationship between graphs and equations corresponding to simple rate problems 11 Coordinate geometry and graphs ACMNA209: Apply index laws to numerical expressions with integer indices 5 Indices ACMNA210: Express numbers in scientific notation 5 Indices YEAR 10A ACMNA264: Define rational and irrational numbers and perform operations with surds and fractional indices 1 Pythagoras’ theorem and surds 5 Indices Money and financial mathematics ACMNA211: Solve problems involving simple interest 2 Working with numbers NSW STAGE 5.1: Solve problems involving earning money 8 Earning money Patterns and algebra ACMNA212: Extend and apply the index laws to variables, using positive integer indices and the zero index 5 Indices ACMNA213: Apply the distributive law to the expansion of algebraic expressions, including binomials, and collect like terms where appropriate 3 Products and factors YEAR 10 ACMNA233: Expand binomial products and factorise monic quadratic expressions using a variety of strategies 3 Products and factors YEAR 10 ACMNA234: Substitute values into formulas to determine an unknown; 7 Equations YEAR 10A ACMNA269: Factorise monic and non-monic quadratic expressions and solve a wide range of quadratic equations derived from a variety of contexts 3 Products and factors Linear and non-linear relationships ACMNA214: Find the distance between two points located on a Cartesian plane using a range of strategies, including graphing software 11 Coordinate geometry and graphs ACMNA215: Sketch linear graphs using the coordinates of two points and solve linear equations 7 Equations 11 Coordinate geometry and graphs YEAR 10 ACMNA235: Solve problems involving linear equations, including those derived from formulas 7 Equations ACMNA294: Find the midpoint and gradient of a line segment (interval) on the Cartesian plane using a range of strategies, including graphing software 11 Coordinate geometry and graphs NSW STAGE 5.2: Interpret and graph linear relationships using the gradient-intercept form of the equation of a straight line 11 Coordinate geometry and graphs SAMPLE CHAPTER ACMNA296: Graph simple non-linear relations with and without the use of digital technologies and solve simple related equations x 11 Coordinate geometry and graphs 9780170193085 9 NEW CENTURY MATHS ADVANCED for the Content description A u s t ra l i a n C u r r i cu l u m New Century Maths Advanced 9 Stages 5.2/5.3 chapter MEASUREMENT AND GEOMETRY Using units of measurement ACMMG216: Calculate the areas of composite shapes 10 Surface area and volume ACMMG217: Calculate the surface area and volume of cylinders and solve related problems 10 Surface area and volume ACMMG218: Solve problems involving the surface area and volume of right prisms 10 Surface area and volume ACMMG219: Investigate very small and very large time scales and intervals 10 Surface area and volume NSW STAGE 5.1: Round numbers to a specified number of significant figures, describe the limits of accuracy of measuring instruments 10 Surface area and volume Geometric reasoning ACMMG220: Use the enlargement transformation to explain similarity and develop the conditions for triangles to be similar 13 Congruent and similar figures ACMMG221: Solve problems using ratio and scale factors in similar figures 13 Congruent and similar figures YEAR 10 ACMMG243: Formulate proofs involving congruent triangles and angle properties; ACMMG244: Apply logical reasoning, including the use of congruence and similarity, to proofs and numerical exercises involving plane shapes 13 Congruent and similar figures NSW STAGE 5.2: Apply interior and exterior angle sum results for polygons to find the sizes of unknown angles 6 Geometry Pythagoras and trigonometry ACMMG222: Investigate Pythagoras’ theorem and its application to solving simple problems involving right-angled triangles 1 Pythagoras’ theorem and surds ACMMG223: Use similarity to investigate the constancy of the sine, cosine and tangent ratios for a given angle in right-angled triangles 4 Trigonometry ACMMG224: Apply trigonometry to solve right-angled triangle problems 4 Trigonometry YEAR 10 ACMMG245: Solve right-angled triangle problems including those involving direction and angles of elevation and depression 4 Trigonometry STATISTICS AND PROBABILITY Chance ACMSP225: List all outcomes for two-step chance experiments, both with and without replacement using tree diagrams or arrays. Assign probabilities to outcomes and determine probabilities for events 12 Probability ACMSP226: Calculate relative frequencies from given or collected data to estimate probabilities of events involving ‘and’ or ‘or’ 12 Probability ACMSP227: Investigate reports of surveys in digital media and elsewhere for information on how data were obtained to estimate population means and medians 12 Probability Data representation and interpretation ACMSP228: Identify everyday questions and issues involving at least one numerical and at least one categorical variable, and collect data directly from secondary sources 9 Investigating data ACMSP282: Construct back-to-back stem-and-leaf plots and histograms and describe data, using terms including ‘skewed’, ‘symmetric’ and ‘bi-modal’ 9 Investigating data ACMSP283: Compare data displays using mean, median and range to describe and interpret numerical data sets in terms of location (centre) and spread 9 Investigating data SAMPLE CHAPTER 9780170193085 xi 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QSJOUFEJOredBQQFBSJOUIFHMPTTBSZ t "VTUSBMJBO$VSSJDVMVNDPOUFOU EFTDSJQUJPOT QSJOUFEJOCMVFBOE NBSLFE"$ BSFMJTUFEBUUIF CFHJOOJOHPGFBDIDIBQUFS t SkillCheckBOEStartUp assignment SFWJFXQSFSFRVJTJUFTLJMMTBOE LOPXMFEHFGPSUIFDIBQUFS BQQMZ JOEFY MBXT UP OVNFSJDBM FYQSFTTJPOT XJUI JOUFHFS JOEJDF T TJNQMJGZ BMHFCSBJD QSPEVDUT BOE RVPUJFOUT VTJOH JOEFY MBXT FYQSFTT OVNCFST JO TDJFOUJmD OPUBUJPO JOUFSQSFU BOE VTF [FSP BOE OFHBUJ WF JOEJDFT 45"(& JOUFSQSFU BOE VTF GSBDUJPOBM JOEJDFT SPVOE OVNCFST UP TJHOJmDBOU mHVSFT JOUFSQSFU XSJUF BOE PSEFS OVNC FST JO TDJFOUJmD OPUBUJPO JOUFSQSFU BOE VTF TDJFOUJmD OPUBUJP O PO B DBMDVMBUPS TPMWF QSPCMFNT JOWPMWJOH TDJFOUJ mD OPUBUJPO SkillCheck Worksheet StartUp assignment 5 MAT09NAWK10050 Worksheet Powers review MAT09NAWK10051 Skillsheet Indices MAT09NASS10020 1 'PS FBDI UFSN i TUBUF UIF CBTF ii TUBUF UIF JOEFY iii XSJUF UIF FYQSFTTJPO JO XPSET a 84 b 48 c h 2 &YQSFTT FBDI SFQFBUFE NVMUJQ d h MJDBUJPO JO JOEFY OPUBUJPO a 232323232 b 33337373 c 333333 7 838 d 10 3 x 3 x 3 x 3 x 3 x e 636363k3k f x3y3x3y3x g a3b3b3b3a h 3n33n3n i q3p3q3p3q3q Summary t * NQPSUBOUGBDUTBOEGPSNVMBTBSF IJHIMJHIUFEJOBSummary CPY Stage 5.3 See Example 10 Exercise 1-04 Generally, any number raised to the power of 1 n is the nth root of that number: pffiffiffi 1 an ¼ n a Simplifying surds 1 Simplify each expression. pffiffiffi2 pffiffiffi2 a pffiffiffi 2 b 5 c 3 3 2 pffiffiffiffiffiffiffiffiffi2 pffiffiffi e pffiffiffi2 0:09 f 2 7 2 g 3 5 See Example 11 2 Simpli fy each surd. pffiffiffi pffiffiffiffiffi a pffiffiffiffiffi 8 b 27 pffiffiffiffiffiffiffi ffi c 24 pffiffiffiffiffi e pffiffiffiffiffi 243 f 45 pffiffiffiffiffi g pffiffiffiffiffi 48 i pffiffiffiffiffiffiffi 96 ffi j 63 pffiffiffiffiffi k 288 pffiffiffiffiffiffiffi ffi m 75 pffiffiffiffiffi n 147 pffiffiffiffiffiffiffiffi o 32 pffiffiffiffiffiffiffi ffi q p 162 ffiffiffiffiffiffiffi ffi r 245 s 125 3 Simplify each expression. pffiffiffiffiffi pffiffiffi a 5 50 pffiffiffiffiffi b 3 8 pffiffiffiffiffi c 4 27 pffiffiffiffiffiffiffiffi pffiffiffiffiffi 40 243 e f 28 2 g 9 pffiffiffiffiffiffiffiffiffiffi 6 pffiffiffiffiffi 3125 i 9 68 pffiffiffiffiffi j 1 k 10 2 72 pffiffiffiffiffiffiffiffi pffiffiffiffiffi m 10 160 pffiffiffiffiffi n 3 75 o 7 68 4 Decide whether each statem ent is true (T) or false (F). pffiffiffi pffiffiffiffiffi p ffiffiffiffiffi a 3 7 ¼ 21 pffiffiffiffiffiffiffi2 b 12 ¼ 6 pffiffiffiffiffi c 9:4 ¼ 9:4 pffiffiffi pffiffiffi d 75 ¼ 5 3 e 3 17 t 1 BHFTDPOUBJOJOHStage 5.3 contentBSF NBSLFECZBTIBEFENBSHJO t (SBEFEFYFSDJTFTBSFMJOLFEUPXPSLFE FYBNQMFTBOEJODMVEFNVMUJQMFDIPJDF RVFTUJPOT FYBNTUZMFQSPCMFNTBOE SFBMJTUJDBQQMJDBUJPOT t 8PSLFETPMVUJPOTGPSTFMFDUFEFYFSDJTF RVFTUJPOTBSFQSPWJEFE pffiffiffiffiffi2 5 10 pffiffiffi h 5 2 2 d d h l p t pffiffiffiffiffi 54 pffiffiffiffiffiffiffi ffi 200 pffiffiffiffiffiffiffi ffi 108 pffiffiffiffiffiffiffi ffi 242 pffiffiffiffiffiffiffi ffi 512 pffiffiffiffiffi d 8 98 pffiffiffiffiffi h 3 24 pffiffiffiffiffi l 3 48 4 pffiffiffiffiffi 52 p 6 Investigation: A lifetime of heartbeats t I nvestigationsFYQMPSFUIF TZMMBCVTJONPSFEFUBJM UISPVHI HSPVQXPSL EJTDPWFSZBOE NPEFMMJOHBDUJWJUJFT How many times does your heart beat in an average lifetime of 80 years? 1 Work in pairs and copy this table. Name Trial 1 Trial 2 Average beats per minute 2 Use two fingers to measure your pulse. Have your partner time you for a minute. Do this twice, record your results in the table and find the average. Just for the record Hairy numbers t J ust for the record DPOUBJOTJOUFSFTUJOHGBDUT BOEBQQMJDBUJPOTPGUIFNBUIFNBUJDTMFBSOU JOUIFDIBQUFS SAMPLE CHAPTER Straight hair + round follicle Wavy hair oval follicle Curly hair flat follicle There are about 110 000 hairs on your head. Each hair grows at the rate of about 1.3 3 103 cm per hour. A single hair lasts about six years. Every day you lose between 30 and 60 hairs. Each hair grows from a small depression in the skin called a follicle (a gland) After the hair falls out 9780170193085 xiii New Century Maths User’s guide t T echnology promotes ICT in the classroom, using spreadsheets, GeoGebra and the Internet Mental skills 4 Technology Similar right-ang led triangles In this activity you will use GeoG ebra to measure and calculate trigonometric ratios. 1 a Before you start, set angle s to measure in degrees. Click Options, Rounding and 1 Decimal Place. Maths without calculators Estimating answers t . FOUBMTLJMMTSFJOGPSDFNFOUBM calculation strategies (‘maths XJUIPVUDBMDVMBUPST A quick way of estimating an answer is to round each number in the calculation. 1 Study each example. a 631 þ 280 þ 51 þ 43 þ 96 600 þ 300 þ 50 þ 40 þ 100 ¼ ð600 þ 300 þ 100Þ þ ð50 þ 40Þ ¼ 1000 þ 90 ¼ 1090 ðActual answer ¼ 1101Þ NelsonNet resources .BSHJOJDPOTMJOLUPQSJOU 1%' BOENVMUJNFEJBSFTPVSDFTGPVOEPOUIF/FMTPO/FUXFCTJUF www.nelsonnet.com.au. These include: Worksheet Venn diagrams Puzzle sheet Geometry crossword Skillsheet Indices Homework sheet Pythagoras’ theorem 1 Video tutorial Worksheets Puzzle sheets of matching activities and crosswords Skillsheets of examples and exercises of prerequisite skills and knowledge Homework sheets for weekly practice and revision, including mental calculation, numeracy and literacy questions Negative indices Worked solutions Exercise 8-10 Technology worksheet Video tutorials of worked examples Worked solutions of selected exercise questions Technology worksheets: Excel Graphing data additional technology activities Quiz ExamView quizzes: interactive Equations and self-marking &BDISFTPVSDFIBTBVOJRVFJEFOUJåFSDPEF'PSFYBNQMF UIFWJEFPUVUPSJBMA1ZUIBHPSBTUIFPSFN has the code MAT09MGVT10001, which stands for Mathematics, Year 9, Measurement and Geometry strand, Video Tutorial 10001. SAMPLE CHAPTER xiv 9780170193085 9 NEW CENTURY MATHS ADVANCED for the A u s t ra l i a n C u r r i cu l u m At the end of each chapter t Power plus is an extension/challenge exercise t Language of maths has a chapter word list and literacy questions t Topic overview has reflection questions and an incomplete mind map t Chapter revision is a review exercise with links to each exercise set of the chapter t Mixed revision is a review exercise after every 3–4 chapters n Language of maths descending fractional power estimate indices quotient negative power reciprocal power index notation product scientific notation significant figures term zero power ascending expanded form base index laws exponent index 1 1 What does a power of 2 mean? ‘power’? 2 Which two words from the list mean key on a calculator used for? or 3 What is the with the same base? Wh i h i d law for dividing terms At the end of the book t General revision exercise t Instructional and Mathematical glossaries (in this book, words printed in red also appear in the glossary) t Answers and Index NelsonNetBook t N elsonNetBook is the interactive digital version of this textbook found on NelsonNet, containing margin icons that link directly to NelsonNet resources t 5PFBDIQBHFPG/FMTPO/FU#PPLZPVDBOBEEOPUFT WPJDF and sound bites, highlighting, weblinks and bookmarks t Zoom and Search functions t $IBQUFSTDBOCFDVTUPNJTFEGPSEJGGFSFOUHSPVQTPGTUVEFOUT SAMPLE CHAPTER 9780170193085 xv Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:32 User ID: elangok 1BlackLining Disabled Number and Algebra 5 Indices The speed of light is about 300 000 000 metres per second. In one year, light travels approximately 9 460 000 000 000 km. Light from the stars travels for many years before it is seen on Earth. Even light from the Sun takes eight minutes to reach the Earth. Powers or indices provide a way to work easily with very large and very small numbers. SAMPLE CHAPTER Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled N E W C E N T U R Y M AT H S A D V A N C E D for the A n Chapter outline n Wordbank Proficiency strands 5-01 Multiplying and dividing terms with the same base 5-02 Power of a power 5-03 Powers of products and quotients 5-04 The zero index 5-05 Negative indices 1 5-06 Fractional indices * n m 5-07 Fractional indices * n 5-08 Summary of the index laws 5-09 Significant figures 5-10 Scientific notation 5-11 Scientific notation on a calculator *STAGE 5.3 9780170193085 ustralian Curriculum U F U F R C R C U F U F U F R C R C R C U F R C U F R C U F U F U F R C R C R C U F PS R C base A number that is raised to a power, meaning it is multiplied by itself repeatedly, for example, in 25, the base is 2. index laws Rules for simplifying algebraic expressions involving powers of the same base, for example, am 4 an ¼ amn. index notation A way of writing repeated multiplication using indices (powers), in the form an, for example 2 3 2 3 2 3 2 3 2 in index notation is 25. negative power A power that is a negative number, as in the term 32. power (or index or exponent) The number of times a base appears in a repeated multiplication, for example, in 25, the power is 5. scientific notation A shorter way of writing very large or very small numbers using powers of 10. For example, 9 460 000 000 000 in scientific notation is 9.46 3 1012. SAMPLE CHAPTER significant figures Meaningful digits in a numeral that tell ‘how many’. For example, 28 000 000 has two significant figures: 2 and 8. 9 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled Chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 Indices n In this chapter you will: • • • • • • • • • apply index laws to numerical expressions with integer indices simplify algebraic products and quotients using index laws express numbers in scientific notation interpret and use zero and negative indices (STAGE 5.3) interpret and use fractional indices round numbers to significant figures interpret, write and order numbers in scientific notation interpret and use scientific notation on a calculator solve problems involving scientific notation SkillCheck Worksheet StartUp assignment 5 1 i state the base ii state the index iii write the expression in words. MAT09NAWK10050 Worksheet Powers review MAT09NAWK10051 For each term: 2 b 48 c h5 a 84 Express each repeated multiplication in index notation. a c e g i Skillsheet Indices MAT09NASS10020 3 232323232 535353535353838 636363k3k a3b3b3b3a q3p3q3p3q3q b 72 c d5 d k2 c ð33 Þ2 g 24 4 2 d 60 h ð8Þ2 c 216 ¼ 6? g 64 ¼ 2? d 144 ¼ 12? h 625 ¼ 5? Evaluate each expression. a 42 3 43 e 91 5 3333333373737 10 3 x 3 x 3 x 3 x 3 x x3y3x3y3x 53n353n3n Write each term in expanded form. a 93 4 b d f h d 5h b 106 4 10 2 f 55 3 5 For each equation, find the missing power. a 8 ¼ 2? e 4096 ¼ 2? b 81 ¼ 3? f 2401 ¼ 7? Investigation: Multiplying and dividing terms with powers 1 Write each expression in expanded form, then evaluate it. a i 22 3 23 ii 25 b i 34 3 33 3 3 6 c i 4 34 ii 4 d i 55 3 53 2 What do you notice about each pair of answers in question 1? 3 Is it true that 24 3 26 ¼ 210? Give a reason for your answer. SAMPLE CHAPTER 180 ii 37 ii 58 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled N E W C E N T U R Y M AT H S A D V A N C E D for the A ustralian Curriculum 9 4 Determine whether each equation is true (T) or false (F). Justify your answer. b 63 3 67 ¼ 621 a 25 3 25 ¼ 210 3 9 27 c 4 34 ¼4 d 35 3 310 ¼ 315 5 Write in words and as a formula the rule for multiplying am and an, two terms with the same base. 6 Use the rule to copy and complete each equation. a 5 4 3 5 2 ¼ 5… b 45 3 43 ¼ 4… c 105 3 107 ¼ … e n 3 3 n8 ¼ … f p 3 3 p7 ¼ … d 93 3 92 ¼ … 7 Evaluate each expression. a i 36 4 33 ii 33 b i 28 4 26 ii 22 8 3 5 8 4 c i 5 45 ii 5 d i 10 4 10 ii 104 8 What do you notice about each pair of answers in question 7? 9 Is it true that 48 4 46 ¼ 42? Give a reason for your answer. 10 Determine whether each equation is true (T) or false (F). Justify your answer. a 310 4 36 ¼ 34 b 48 4 42 ¼ 44 c 212 4 23 ¼ 24 d 610 4 65 ¼ 65 11 Write in words and as a formula the rule for dividing am and an, two terms with the same base. 12 Use the rule to copy and complete each equation. a 26 4 23 ¼ 2… b 108 4 106 ¼ 10… c 37 4 32 ¼ 11 6 8 5 d 4 44 ¼… e x 4x ¼… f g12 4 g10 ¼ … Multiplying and dividing terms with 5-01 the same base Video tutorial Simplifying with the index laws MAT09NAVT00002 Consider 5 4 3 5 3 ¼ ð5 3 5 3 5 3 5Þ 3 ð5 3 5 3 5Þ ¼ 5353535353535 ¼ 57 ) 5 4 3 5 3 ¼ 5 4þ3 ¼ 57 Summary SAMPLE CHAPTER When multiplying terms with the same base, add the powers: am 3 an ¼ amþn 9780170193085 181 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled Chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 Indices The rule above is called an index law. Index is another name for power. The plural of index is indices (pronounced ‘in-de-sees’). Proof: 3a3 3ffla} 3 a|fflfflfflfflfflfflfflfflfflfflffl 3a3 3ffla} a m 3 a n ¼ a|fflfflfflfflfflfflfflfflfflfflffl ffl{zfflfflfflfflfflfflfflfflfflfflffl ffl{zfflfflfflfflfflfflfflfflfflfflffl m factors n factors ¼ a|fflfflfflfflfflfflfflfflfflfflffl 3a3 3ffla} ffl{zfflfflfflfflfflfflfflfflfflfflffl ðm þ nÞ factors ¼ a mþn Example 1 Simplify each expression, writing the answer in index notation. a 84 3 85 b 10 3 103 c d3 3 d5 d 4m 2 3 3m6 e 3r 2t 3 6r4t 3 Solution a 8 4 3 8 5 ¼ 8 4þ5 b 10 3 10 3 ¼ 101 3 10 3 ¼ 89 d 3 3 d 5 ¼ d 3þ5 ¼ 101þ3 d 4m 2 3 3m6 ¼ ð4 3 3Þ 3 ðm 2 3 m 6 Þ Consider c ¼ d8 ¼ 104 e 3r 2 t 3 6rt 3 ¼ ð3 3 6Þ 3 ðr 2 3 r 1 Þ 3 ðt 1 3 t 3 Þ ¼ 12m 2þ6 ¼ 18r 2þ1 t 1þ3 ¼ 12m8 ¼ 18r 3 t 4 6 56 4 54 ¼ 54 5 653653653653535 ¼ 65365365365 ¼ 535 ¼ 52 6 4 ) 5 4 5 ¼ 5 64 ¼ 52 Summary When dividing terms with the same base, subtract the powers: m a m 4 a n ¼ aa n ¼ a mn This is another index law. m a m 4 a n ¼ aa n Proof: 6a36a3a3a3a3 3a ¼ 6a36a3a3 3a ðm factors) ðn factors) ½ðm nÞ factors] SAMPLE CHAPTER ¼ a3a3 3a ¼ a mn 182 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled N E W C E N T U R Y M AT H S A D V A N C E D for the A Example ustralian Curriculum 9 2 Simplify each expression, writing the answer in index notation. 8 a 8 5 4 83 b 10 10 8x 3 y7 d 20w 10 4 5w 2 e 24x 2 y c d 20 4 d 4 Solution a 8 5 4 83 ¼ 853 b ¼ 82 20w 10 2 16 5w ¼ 4w 102 d 20w 10 4 5w 2 ¼ 4 e 10 8 ¼ 1081 10 ¼ 107 d 20 4 d 4 ¼ d 204 c ¼ d 16 1 xy 6 8x 3 y 7 6 8x 32 y 71 ¼ ¼ 3 24x 2 y1 3 24 ¼ 4w 8 Exercise 5-01 Multiplying and dividing terms with the same base 1 Which expression is equal to 512 3 53? Select the correct answer A, B, C or D. B 515 C 2515 D 2536 A 59 2 Simplify each expression, writing the answer in index notation. a d g j m p 103 3 102 74 3 7 6 3 62 3 63 3 64 x 3 x4 b3 3 b10 y 3 y3 3 y2 b e h k n q 2 3 24 8 3 83 3 8 4 44 3 44 3 44 g4 3 g4 p10 3 p10 m 3 3 m 3 m4 c f i l o r 32 3 35 54 3 5 3 54 34 3 30 3 37 w7 3 w r3r n8 3 n2 3 Which expression is equal to 104 3 10? Select the correct answer A, B, C or D. B 100 4 C 10 4 D 10 5 A 100 5 4 Simplify each expression. a 3p2 3 2p5 d h3 3 5h8 g 5n8t 3 6n8t 4 j 8p4m5 3 4p3m5 5 4y10 3 3y 2 3q 3 8q8 2ab3 3 15ab 16qr8 3 3q7 c f i l 6m 3 3m8 2a 2 3 5a 5 3e4g 3 3 e6g 2 9u 3v 3 6uv 2w8 Which expression is equal to 512 4 5 3 ? Select the correct answer A, B, C or D. 4 A 5 6 b e h k 9 4 B 5 C 1 See Example 1 See Example 2 9 D 1 Simplify each expression, writing the answer in index notation. a 107 4 10 5 8 d 52 5 g 74 4 73 9780170193085 b 85 4 8 12 e 93 9 20 h 2 2 c 2015 4 20 5 27 f 23 2 SAMPLE CHAPTER i 114 4 114 183 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled Chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 Indices j p15 4 p10 k n7 4 n l 20 m h4 h n y8 y2 25 q ww 12 o a4 a p b16 4 b15 w 24 4 w6 r m16 4 m16 7 Which expression is equal to 10 4 4 10? Select the correct answer A, B, C or D. B 14 C 13 D 10 3 A 10 4 8 Simplify each expression. a 10y15 4 5y 3 b 20w 9 4 4w 3 c 24r 8 4 3r 4 d 30x3 x 10 e 10m 2m f g 14d 4h10 4 7hd 2 h 15x6y8 4 15xy 4 i 6e 25d 40 4 18e 5d 4 10 8 k 45a 5b 5a l j 12q 5 t 4 16q 4 t 3 4g12 8g 6 36pq3 r5 24qr Investigation: Powers of powers 1 Write each expression in expanded form, then evaluate it. a i (23)2 ii 26 b i (34)3 ii 312 2 3 6 5 4 c i (5 ) ii 5 d i (2 ) ii 220 2 What do you notice about each pair of answers in question 1? 3 Is it true that: (27)3 ¼ 221? Give a reason for your answer. 4 Determine whether each equation is true (T) or false (F). Justify your answer. a (35)3 ¼ 315 b (23)2 ¼ 25 c (210)4 ¼ 214 2 5 10 3 6 18 d (4 ) ¼ 4 e (3 ) ¼ 3 f (52)4 ¼ 56 5 Write in words and as a formula the rule for raising am to a power of n, that is, (am)n. 6 Use the rule to copy and complete each equation. a (37)2 ¼ 3… b (52)6 ¼ 5… c (45)2 ¼ 4… 3 4 3 7 d (a ) ¼ a… e (8 ) ¼ … f (k4)6 ¼ … Puzzle sheet Indices puzzle 5-02 Power of a power MAT09NAPS10053 Consider Video tutorial Simplifying with the index laws MAT09NAVT00002 ð5 3 Þ4 ¼ 5 3 3 5 3 3 5 3 3 5 3 ¼ ð5 3 5 3 5Þ 3 ð5 3 5 3 5Þ 3 ð5 3 5 3 5Þ 3 ð5 3 5 3 5Þ ¼ 53535353535353535353535 ¼ 512 ) ð53 Þ4 ¼ 53 3 4 SAMPLE CHAPTER ¼ 512 184 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled N E W C E N T U R Y M AT H S A D V A N C E D for the A ustralian Curriculum 9 Summary When raising a term with a power to another power, multiply the powers: ða m Þn ¼ a m 3 n Proof: ða m Þn ¼ |fflfflfflfflfflfflfflfflfflfflfflfflfflfflfflffl a m 3 a m ffl3 3 afflm} {zfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflffl n factors ¼ a|fflfflfflfflfflfflfflfflfflfflffl 3a3 3ffla} 3 a|fflfflfflfflfflfflfflfflfflfflffl 3a3 3ffla} 3 |fflfflfflfflfflfflfflfflfflfflfflfflfflffl 3 a 3 affl{zfflfflfflfflfflfflfflfflfflfflfflfflfflffl 3 3ffla} ffl{zfflfflfflfflfflfflfflfflfflfflffl ffl{zfflfflfflfflfflfflfflfflfflfflffl m factors m factors m factors |fflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflffl{zfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflfflffl} n lots of m factors ¼ am3n Example 3 Simplify each expression, writing the answer in index notation. a (8 5)2 d (5v4)3 b (d 3)5 e (n)6 c (2g)4 f (3t 4)3 a ð8 5 Þ2 ¼ 25 3 2 ¼ 210 b ðd 3 Þ5 ¼ d 3 3 5 ¼ d 15 c ð2gÞ4 ¼ 24 3 g 4 ¼ 16g 4 d ð5v 4 Þ3 ¼ 5 3 3 ðv 4 Þ3 ¼ 125 3 v 4 3 3 ¼ 125v12 e ðnÞ6 ¼ ð1Þ6 3 n6 ¼ 1 3 n6 ¼ n6 f ð3t 4 Þ3 ¼ ð3Þ3 3 ðt 4 Þ3 ¼ 27 3 t 4 3 3 ¼ 27t 12 Solution Exercise 5-02 1 Which expression is equal to (10 3)3? Select the correct answer A, B, C or D. A 30 3 2 3 B 100 C 109 See Example 3 D 106 Simplify each expression, writing the answer in index notation. a (43)2 g (100)2 b (52)8 h (64)5 c (33)4 i (53)5 d (27)4 j (e 2)4 e (21)2 k (t 5)5 f (9)3 l (y 3)7 m (c1)5 s (2x)10 n (m7)5 t (5n3)8 o (y4)4 u (4d 3)3 p (h0)6 v (k 5)9 q (q6)3 w (d 3)4 r (w4)1 x (2a8)8 Which expression is equal to (3)5? Select the correct answer A, B, C or D. A 36 4 Power of a power B 35 C 35 D 15 Simplify each expression. a (2d 3)4 g (10d 5)4 m (2r)4 s (4w5)4 9780170193085 b (5m 3)2 h (3e)3 c (4y5)2 i (2b4)1 d (3x2)4 j (6d 6)2 e (5u6)5 k (3f 4)5 f (2w5)3 l (2c3)10 n (5t)3 o (3m 3)2 p (y 3)12 q (x)3 r (m 3)10 t (3f )5 u (3p2)3 v (3h5)4 w (10k)2 x (8y 3)1 SAMPLE CHAPTER 185 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled Chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 Indices Video tutorial Simplifying with the index laws MAT09NAVT0002 5-03 Powers of products and quotients Consider ð2 3 5Þ3 ¼ ð2 3 5Þ 3 ð2 3 5Þ 3 ð2 3 5Þ ¼ 23232353535 Homework sheet ¼ 23 3 5 3 Indices 1 ) ð2 3 5Þ3 ¼ 23 3 5 3 MAT09NAHS10005 Summary When raising a product of terms to a power, raise each term to that power: ðabÞn ¼ a n bn Proof: ðabÞn ¼ ab 3 ab 3 3 ab |fflfflfflfflfflfflfflfflfflfflfflfflfflfflffl{zfflfflfflfflfflfflfflfflfflfflfflfflfflfflffl} n factors ¼ a|fflfflfflfflfflfflfflfflfflfflffl 3a3 3ffla} 3 b|fflfflfflfflfflfflfflfflfflfflffl 3b3 3fflb} ffl{zfflfflfflfflfflfflfflfflfflfflffl ffl{zfflfflfflfflfflfflfflfflfflfflffl n factors ¼ an bn Example n factors 4 Simplify each expression. a (2gh2)5 b (p3q4)2 Solution a ð2ghÞ5 ¼ ð2Þ5 3 g 5 3 ðh2 Þ5 Consider b ð p 3 q 4 Þ2 ¼ ð p 3 Þ2 3 ðq 4 Þ2 ¼ 32 3 g 5 3 h 2 3 5 ¼ p 3 3 2 3 q4 3 2 ¼ 32g 5 h10 ¼ p6 q8 6 5 ¼53535353535 8 8 8 8 8 8 8 5 3 5 3 5 3 5 3 5 3 5 ¼ 83838383838 6 5 ¼ 6 8 6 5 56 ) ¼ 6 8 8 SAMPLE CHAPTER 186 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled N E W C E N T U R Y M AT H S A D V A N C E D for the A ustralian Curriculum 9 Summary When raising a quotient of terms to a power, raise each term to that power: n a ¼ an b bn n a a a a ¼ 3 3 3 b b|fflfflfflfflfflfflfflfflfflfflfflfflffl{zfflfflfflfflfflfflfflfflfflfflfflfflffl} b b n factors a 3 a 3 3 a ðn factorsÞ ¼ b 3 b 3 3 b ðn factorsÞ n a ¼ n b Proof: Example 5 Simplify each expression. 2 7c a d b 4k 2 5 3 Solution a 7c d 2 ð7cÞ2 ¼ 2 d 72 c 2 ¼ 2 d 2 49c ¼ 2 d b 4 ¼ ð4k 2 Þ3 53 43 ðk 2 Þ3 125 6 ¼ 64k 125 Powers of products and quotients B 16 3 25 Simplify each expression. b (x 2y)5 a (ab)3 g (ek 3)3 3 3 Which expression is equal to ð4 3 5Þ2 ? Select the correct answer A, B, C or D. A 16 3 25 2 4k 2 5 ¼ Exercise 5-03 1 c (l 3m 5)6 C 8 3 10 d (6dp2)4 See Example 4 D 8 3 10 e (8k 4y 5)2 f (3m 2n)5 h (w 3x4)7 i (8d 3y 5)2 j (4b2c 3)4 k (3a 3d)3 l (2p2q3)4 3 Which expression is equal to 3 ? Select the correct answer A, B, C or D. 4 9 9 B C 27 D 27 A 12 12 64 64 Simplify each expression. 5 4 2 3 4 5 8 2 6 m 5 2n w m2 a b c d e f 3 p x 7 2 4n t 4 2 4 3 7k 4 3r 2 a2 b 2 5 g 2 h 5h i j k l 3 10 6 t2 d5 3c 2 See Example 5 SAMPLE CHAPTER 9780170193085 187 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled Chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 Indices Worked solutions Exercise 5-03 MAT09NAWS10503 5 Simplify each expression. a (2x10y15)3 3 5x 2y 3 c 18q5r 8 4 (3qr 2)2 d (18q5r 8 4 3qr 2)2 b (2x10y15 3 5x 2y 3)3 3 3a 5 x6 e ax g (4p3h10)2 3 2p2h9 h (4p3h10)2 4 2p2h9 i (4p3h10 3 2p2h9)2 f 3a 5 x6 ðaxÞ4 Investigation: The power of zero What is the value of a number raised to a power of 0, for example, 20? 1 Copy and complete each table of decreasing powers. Notice the pattern in your answers. a b Power of 2 Number Power of 3 Number 25 35 32 243 4 2 34 16 33 23 2 2 32 1 2 31 20 30 2 Simplify each expression in index notation. a 34 3 30 b 52 3 50 c 20 3 27 d 70 3 73 e 45 3 40 f 50 3 57 5 0 5 0 2 0 3 0 6 0 g 2 42 h 3 43 i 4 44 j 9 49 k 5 45 l 84 4 80 3 Any number will remain unchanged when multiplied by what? 4 Any number will remain unchanged when divided by what? 5 What is the answer when any number is raised to the power of 0, that is, a0? Justify your answer. 5-04 The zero index 3 5 Consider 5 3 4 5 3 ¼ 3 5 ¼ 1 Any number divided by itself equals 1. But also 5 3 4 5 3 ¼ 533 ¼ 50 ) 50 ¼ 1 Summary Any number raised to the power of zero is equal to 1. SAMPLE CHAPTER a0 ¼ 1 188 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled N E W C E N T U R Y M AT H S A D V A N C E D for the A am 4 am ¼ 1 Proof: m m a 4a ¼ a But also ustralian Curriculum 9 Any number divided by itself equals 1. mm ¼ a0 ) a0 ¼ 1: Example 6 Simplify each expression. a 110 d (3r)0 b (8)0 e 3r 0 c g0 f 80 a 110 ¼ 1 b (8)0 ¼ 1 c g0 ¼ 1 d (3r)0 ¼ 1 e 3r 0 ¼ 3 3 r 0 f Solution 80 ¼ 1 3 80 ¼ 331 ¼3 Exercise 5-04 1 2 ¼ 1 3 1 ¼ 1 The zero index Simplify each expression. See Example 6 a 20 b (2)0 c 20 0 2 g 3 0 p k 3 d (m)0 e m0 f ð4aÞ0 i 10000 j ðp þ 3Þ0 m (9k)0 n (x 2y)0 o (xyw)0 p (ab)0 q (6r)0 r (6r)0 s 6r 0 t 6(r)0 u (cd)0 v (7x 2)0 w 3(a 2b3)0 x (5v 5w4)0 c 2m0 þ (2m)0 d 2m0 (2m)0 Exercise 5-04 0 0 MAT09NAWS10504 h 7x0 l 2b0 Simplify each expression. a 70 þ 20 0 Worked solutions b 70 20 0 0 0 e (6a) þ 6a f (6a) 6x i 30 3 50 j 32 3 50 m 2w0 3 3p0 q 12p0 ð2pÞ0 0 g (5y) 4 0 1 1 k þ y0 2 2 h (5y) 4 0 0 1 1 y l þ 2 2 n 12u0 4 3 o (5d 0)3 p 8b0 (3b0)2 r 6n3 4 2n3 s 12q 5 36q 5 t ð3x 3 Þ3 4 x9 SAMPLE CHAPTER 9780170193085 189 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled Chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 Indices Mental skills 4 Maths without calculators Adding or multiplying in any order Numbers can be added or multiplied in any order. We can use this property to make our calculations simpler. 1 Study each example. a 19 þ 5 þ 5 þ 1 ¼ ð19 þ 1Þ þ ð5 þ 5Þ ¼ 20 þ 10 ¼ 30 b 13 þ 8 þ 20 þ 27 þ 80 ¼ ð13 þ 27Þ þ ð20 þ 80Þ þ 8 ¼ 40 þ 100 þ 8 ¼ 148 c 2 3 36 3 5 ¼ ð2 3 5Þ 3 36 ¼ 10 3 36 ¼ 360 d 25 3 11 3 4 3 7 ¼ ð25 3 4Þ 3 ð11 3 7Þ ¼ 100 3 77 ¼ 7700 2 3 Now evaluate each sum. a 45 þ 16 þ 45 þ 4 þ 7 c 18 þ 91 þ 9 þ 20 e 24 þ 16 þ 80 þ 44 þ 10 g 100 þ 36 þ 200 þ 10 þ 90 i 70 þ 50 þ 30 þ 25 þ 25 Now evaluate each product. a 83435 d 5 3 11 3 40 g 3 3 20 3 7 3 5 b d f h j 38 þ 600 þ 50 þ 12 þ 40 75 þ 33 þ 7 þ 25 56 þ 5 þ 20 þ 15 þ 4 54 þ 27 þ 9 þ 16 þ 3 32 þ 120 þ 40 þ 80 þ 40 b 50 3 7 3 2 e 12 3 2 3 3 h 6383532 c 33536 f 2 3 4 3 25 3 8 i 2 3 3 3 2 3 11 Investigation: Negative powers What is the value of a number raised to a negative power, for example, 21 or 22? 1 Copy and complete each table showing decreasing powers. Notice the pattern in your answers. a Power of 2 23 22 21 20 21 22 23 Number 8 4 b Power of 10 103 102 101 100 101 102 103 Number 1000 SAMPLE CHAPTER 190 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled N E W C E N T U R Y M AT H S A D V A N C E D for the A ustralian Curriculum 9 2 Copy and complete this table showing decreasing powers in expanded form. Notice the pattern in your answers. a Power of 5 33 32 31 30 31 32 33 Expanded form 33333 333 3 1 1 3 1 ¼ 1 3 3 3 32 1 ¼ 1 3 3 3 3 3 33 b Power of 5 53 52 51 50 51 52 53 54 55 Expanded form 53535 34 35 3 If 32 ¼ 12 and 53 ¼ 13 , then write each negative power in a similar way. 3 5 1 a 4 b 74 c 26 4 Simplify each expression in index notation. a 104 4 107 5 Consider b 23 4 28 c 34 4 35 d 52 4 58 e a4 4 a6 f a 4 a4 10 3 10 3 10 3 10 104 ¼ 107 10 3 10 3 10 3 10 3 10 3 10 3 10 1 ¼ 10 3 10 3 10 ¼ 13 10 104 47 But also 107 ¼ 10 ¼ 103 ) 103 ¼ 1 3 10 Use the method above to show that: 3 4 2 4 c 58 ¼ 52 ¼ 16 a 28 ¼ 25 ¼ 15 b 35 ¼ 31 ¼ 1 d a6 ¼ a2 ¼ 12 3 2 a 2 3 5 5 a 6 Write in words and as a formula the rule for raising a to a negative power n, that is, an. Technology Negative powers In this activity we will discover the pattern for negative powers. We will consider base values from 2 to 10 shown in column A and indices (powers) 1, 2 and 3 shown in row 1. On a spreadsheet, the symbol for power is ^ (called a carat, press SHIFT 6). For example, 31 is entered as 3^ 1. SAMPLE CHAPTER 9780170193085 191 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled Chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 Indices 1 Create a spreadsheet as shown below. 2 We will first examine the power of 1. In cell B4, enter 5A4^ $B$1 to calculate 21. $B$1 is an absolute cell reference, which ensures that the cell does not change when a formula is copied. This means that in column B, the power will always refer to cell B1 (1) only. Fill Down from cell B4 to B12. 3 Use Format cells to set column B decimals to Fraction and Up to three digits. 4 Compare your answers in column B with the original values in column A. Can you describe the pattern when a base is raised to a power of 1? 5 Now consider powers of 2. Adapt steps from 1 to 3 for column C. Use Fill Down from cell C4 to C12. 6 Compare your answers in column C with the original values in column A. Can you describe the pattern when a base is raised to a power of 2? SAMPLE CHAPTER 7 Now consider powers of 3. Adapt steps for column D. In cell D4, enter the formula 5A4^ $D$1. Note: D12’s fraction is missing as it has 4 digits in the denominator, which the spreadsheet doesn’t allow for. Can you figure out what the fraction should be? 192 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled N E W C E N T U R Y M AT H S A D V A N C E D for the A ustralian Curriculum 9 8 Compare your answers in column D with the original values in column A. Can you describe the pattern when a base is raised to a power of 3? 9 Write a rule for negative powers, given the answers you have found in this activity. Discuss with other students in your class. Worksheet 5-05 Negative indices Power calculations MAT09NAWK10056 0 2 Consider 20 4 23 ¼ 3 2 ¼ 13 2 Video tutorial Negative indices MAT09NAVT10010 But also 20 4 23 ¼ 203 ¼ 23 ¼ 13 2 ) 23 Summary A number raised to a negative power gives a fraction (with a numerator of 1): an ¼ a1n Proof: But also 0 a0 4 a n ¼ aa n ¼ a1n a0 4 a n ¼ a0n ) an Example ¼ an ¼ a1n 7 Simplify each expression using a positive index (power). a 53 b 3n2 c ð3nÞ2 b 3n2 ¼ 3 3 n2 ¼ 3 3 12 1 n 3 ¼ 2 n c d p2q3 Solution a 53 ¼ 13 5 1 ð3nÞ2 ¼ 12 9n ð3nÞ2 ¼ 1 2 3 3 d p q ¼ p2 3 q q3 ¼ 2 p SAMPLE CHAPTER 9780170193085 193 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled Chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 Indices The reciprocal as a power Consider 91 ¼ 1 9 1 is the reciprocal of 9. 9 1 2 ¼ 1 Consider 3 2 3 ¼ 14 2 3 ¼ 13 3 2 3 ¼ 2 ¼ 11 2 Summary A number raised to a power of 1 gives its reciprocal. a1 ¼ 1a 1 a ¼ ba b Example 8 Simplify each expression. 1 4 a 3 b 1 y 5 b 1 y 5 ¼y 5 Solution a Stage 5.3 1 4 3 ¼ 3 4 Negative powers of quotients 2 4 ¼ 12 Consider 5 4 5 1 ¼ 16 25 ¼ 1 4 16 25 SAMPLE CHAPTER 194 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled N E W C E N T U R Y M AT H S A D V A N C E D for the A ustralian Curriculum ¼ 1 3 25 16 25 ¼ 16 2 ¼ 52 4 2 ¼ 5 4 9 Stage 5.3 Summary A number raised to a power of –n gives its reciprocal raised to the power of n. n n n a ¼ ba ¼ ba n b Proof: n a ¼ 1n a b b 1 ¼ n a bn bn ¼ an n ¼ ba Example 9 Simplify each expression. 3 4 a 3 b Solution a 3 3 4 ¼ 3 3 4 27 ¼ 64 b 21 2 2 2 2 21 ¼ 5 2 2 2 2 ¼ 5 4 ¼ 25 c c 3a 2 b4 2 4 2 3a ¼ b 3a b4 8 ¼ b2 9a SAMPLE CHAPTER 9780170193085 195 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled Chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 Indices Exercise 5-05 See Example 7 1 Simplify each expression using a positive index. a 62 e g5 i a4 2 3 Worked solutions 4 Exercise 5-05 MAT09NAWS10505 See Example 8 Stage 5.3 See Example 9 5 6 Negative indices b 57 f z1 j 53 c 31 g n3 k yd d 102 h t2 l rm Evaluate each expression, giving your answers in fraction form. b 54 c 61 a 32 1 7 e 25 f 2 g 43 10 3 i 2 j 3 k 62 d 72 h 106 l 94 Write each expression using a negative index. a 12 b 1n c 13 n 8 1 2 1 e f g 3 105 a4 i 6a k 25 j 42 t w d 1 8 h 1 b l 53 d Simplify each expression using positive indices. b 2b5 c 3e3 a 5h1 d 4n2 e pb2 f r 2s4 g w2y h d 3y 3 i (2m)1 j k (4h)2 l m 3m 3p2 n 15k1w4 o 12x2y3 p 12x2y 3 q (3h)2 r (4k)3 s (2c)4 t (8y)1 u 4pq3 v 4p1q3 w vm2 x v1m2 (xy)1 Simplify each expression. 1 1 b 8 a 2 7 5 1 1 5 e 3 f 4 2 1 1 m 5r i j 2 4 Simplify each expression. 2 2 b 2 a 1 4 3 5 4 4 5 e f 3 4 2 3 k 3 i j x 3 2 2 5 2d h m n 5t m3 9 1 10 1 g x 3 1 2 k 3z c 1 6 10 2 1 g 2 4 4 a2 k 4 3 2 5d o 3p4 c (5k)3 1 3 2 1 h 5a 1 1 l v d 3 5 2 3 2 h 1 5 2 4 l 3g3 3 3 3c p 4a 2 d SAMPLE CHAPTER 196 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled N E W C E N T U R Y M AT H S A D V A N C E D for the A ustralian Curriculum 1 5-06 Fractional indices n 9 Stage 5.3 We know now the meaning of zero and negative indices, that is, a0, a1 and an. 1 1 What is the meaning of fractional indices, that is, a 2 and a n ? 1 2 1 Consider 25 2 ¼ 25 2 3 2 Power of a power 1 ¼ 25 ¼ 25 pffiffiffiffiffi 2 but 25 ¼ 25 pffiffiffiffiffi 1 ) 25 2 ¼ 25 ¼ 5 Summary Any number raised to the power of 1 is the square root of that number: 2 pffiffiffi 1 a2 ¼ a 1 2 1 a2 ¼ a232 ¼ a1 pffiffiffi 2 ¼ a But ð aÞ ¼ a pffiffiffi 1 ) a2 ¼ a 1 3 1 Now consider 27 3 ¼ 273 3 3 ¼ 271 ffiffiffiffiffi 3 ¼ 27 p 3 but 27 ¼ 27 pffiffiffiffiffi 1 ) 27 3 ¼ 3 27 ¼ 9 Proof: Power of a power Summary Any number raised to the power of 1 is the cube root of that number: 3 pffiffiffi 1 a3 ¼ 3 a 1 3 1 a3 ¼ a333 ¼ a1 pffiffiffi 3 ¼ a But ð 3 aÞ ¼ a 1 pffiffiffi ) a3 ¼ 3 a 1 5 1 Now consider 32 5 ¼ 32 5 3 5 ¼ 321 ¼ 32 Proof: Power of a power SAMPLE CHAPTER 9780170193085 197 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled Chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 Indices Stage 5.3 1 5 pffiffiffiffiffi 1 If 32 5 ¼ 32, then 32 5 is called the 5th root of 32, written 5 32. 25 ¼ 32 pffiffiffiffiffi 1 ) 32 5 ¼ 5 32 ¼ 2 Summary Generally, any number raised to the power of 1n is the nth root of that number: pffiffiffi 1 an ¼ n a Proof: 1 n 1 an ¼ an 3 n ¼ a1 ¼a p ffiffi ffi n But ð n aÞ ¼ a 1 pffiffiffi ) an ¼ n a Example 10 Evaluate each expression. 1 1 a 900 2 Solution 1 a 900 2 ¼ pffiffiffiffiffiffiffiffi 900 1024 1 10 c 1024 10 1 b 125 3 ¼ ¼ 30 c 1 b 125 3 ffiffiffiffiffiffiffiffi p 3 125 ¼5 pffiffiffiffiffiffiffiffiffiffi ¼ 10 1024 Enter on calculator: 10 ¼2 10 because 2 3 1024 = ¼ 1024 Summary On a calculator, the nth root key is 3 or before pressing or yx respectively. Example c ffiffiffi p 4 n d SAMPLE CHAPTER Solution 198 SHIFT pffiffiffi 1 8 ¼ 82 or 2ndF key 11 Write each expression using a fractional index. pffiffiffiffiffi pffiffiffi a 8 b 3 36 a , found by pressing the b p ffiffiffiffiffi 1 3 36 ¼ 36 3 c 1 ffiffiffi p 4 n ¼ n4 d ffiffiffiffiffi p 7 ab ffiffiffiffiffi p 1 7 ab ¼ ðabÞ7 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled N E W C E N T U R Y M AT H S A D V A N C E D for the A Exercise 5-06 1 1 a 25 1 2 e 32 1 5 See Example 10 b 343 1 3 c 625 f ð0:027Þ 1 1 3 1 2 d 1000 1 2 1 g ð0:04Þ 1 h 64 3 1 j ð729Þ3 1 3 k 256 8 l 1 3125 5 Write each expression using a radical (root) sign. 1 1 1 b 12 3 c g2 1 a 10 2 1 1 e ð8rÞ2 f ð6hÞ6 g ð5j 8 Þ5 d m4 1 h 90ab 9 3 Write each expression using a fractional index. p pffiffiffi ffiffiffiffiffi 3 c a p5ffiffiffiffiffi b p 49 ffiffiffiffiffi e 6 66 f 4 64 g pffiffiffi pffiffiffi k i a j 3q pffi pffiffiffiffiffi m 5t n xy o pffiffiffiffiffi 20 p ffiffiffiffiffiffiffiffi 8 144 ffiffiffi p 7 h ffiffiffiffiffiffiffiffiffiffi p 4 100f pffiffiffiffiffiffiffiffi d 5p400 ffiffiffiffiffiffiffiffiffiffi h 10 1000 p ffiffiffi ffi 6 l p w ffiffiffiffiffiffiffiffi ffi p 3 2mn 4 Evaluate each expression correct to 2 decimal places. p ffiffiffiffiffiffiffiffi 1 1 3 2 a 20 3 b 215 c p 144 p ffiffiffiffiffiffiffiffiffiffi ffiffiffiffiffiffiffiffiffiffiffi 1 g 5 754 f 4 1111 e ð666Þ3 pffiffiffiffiffiffiffiffiffiffi d p2001 ffiffiffiffiffiffiffiffiffiffiffi h 6 0:008 5 Simplify each expression. 1 1 1 1 1 b e3 3 e 33 e 3 a b2 3 b2 1 3 2 3 1 9 3 e 2t 3 5t i 8v 6 w f 9 Stage 5.3 Fractional indices n Evaluate each expression. i ð8Þ3 2 ustralian Curriculum 6a j 40a 1 10 3 2 1 3 c y3y5 2 4 8a 1 g ðn 1 10 12 1 1 3 l Worked solutions 2 d m5 3 m5 h 16a 2 b6 m 4 Þ4 k 35x 4 5x See Example 11 1 2 Exercise 5-06 MAT09NAWS10506 3 4 36y 4 4y m 5-07 Fractional indices n 2 3 What is the meaning of fractional indices such as a 3 and a 2 ? 1 3 3 Power of a power Consider 32 5 ¼ 32 5 pffiffiffiffiffi3 ¼ 5 32 ¼ 23 ¼8 1 3 or consider 32 5 ¼ 323 5 ffiffiffiffiffiffiffi p 5 ¼ 323 pffiffiffiffiffiffiffiffiffiffiffiffiffi ¼ 5 32 768 ¼8 Power of a power Summary SAMPLE CHAPTER m an ¼ 9780170193085 p ffiffiffi n a m or ffiffiffiffiffiffi p n m a 199 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled Chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 Indices Stage 5.3 1 m 1 m or ða m Þn an ¼ an pffiffiffiffiffiffi pffiffiffi m ¼ n a or n a m Proof: Note: Taking the root first often makes the calculation simpler. Example 12 Evaluate each expression. 2 4 1 Solution 2 a 83 ¼ pffiffiffi2 3 8 4 b 27 3 ¼ ¼ 22 ¼4 Example 3 c 643 b 27 3 a 83 pffiffiffiffiffi4 3 27 c ¼ 34 ¼ 81 d 164 1 643 ¼ 1 1 64 3 1ffiffiffiffiffi ¼p 3 64 1 ¼ 4 3 d 164 ¼ 1 3 16 4 1 ¼ pffiffiffiffiffi 4 16 ¼ 13 2 1 ¼ 8 3 13 3 Evaluate 300 5 correct to two decimal places. Solution 3 Enter on calculator: 300 300 5 ¼ 30:63887063 . . . 3 5 = 30:64 Example 14 Write each expression using a fractional index. pffiffiffiffiffi pffiffiffiffiffi a 4 p3 b b7 Solution a p ffiffiffiffiffi 4 p3 ¼ p3 3 ¼ p4 1 4 b pffiffiffiffiffi b7 ¼ b7 7 ¼ b2 1 2 1ffiffiffiffiffi c p 3 q4 c 1ffiffiffiffiffi ¼ 1 p 1 3 q 4 ðq 4 Þ 3 4 ¼ 14 or q3 q3 SAMPLE CHAPTER 200 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled N E W C E N T U R Y M AT H S A D V A N C E D for the A Example ustralian Curriculum 9 Stage 5.3 15 Simplify each expression. qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 4 a ð16r 2 Þ3 b ffiffiffiffiffiffiffiffi p 3 27k b pffiffiffiffiffiffiffiffi2 2 3 27k ¼ ð27k Þ3 2 c ð32a 5 Þ 35 Solution a qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 4 ð16r 2 Þ3 ¼ 16r 2 3 4 3 3 4 234 3 2 ¼ 9k 3 5 3 3 3 ¼ 32 5 a 5 3 5 ¼ 8a3 m n See Example 12 5 3 f 64 2 c 128 4 3 g 32 2 i 1000 3 3 3 4 d 27 3 5 3 1 l 814 4 3 p 31255 4 t 102410 o 2564 3 7 s 1287 r 4002 Evaluate each expression correct to two decimal places. 7 3 5 b 85 c 50 4 a 15 4 e 100 34 f 16 3 5 e p ffiffiffiffiffiffi 3 m5 f p ffiffiffiffiffiffi 5 m3 2 3 a ð16n Þ b ð8wÞ pffiffiffiffiffiffiffiffiffiffi5 4 e 81r 4 qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 4 f ð81h12 Þ3 i 125b6 23 d 6 2 g 12 Simplify each expression. 3 4 4 See Example 13 23 32 Write each expression using a fractional index. pffiffiffiffiffi pffiffiffiffiffi a 7 g2 b e5 j ð625t 2 Þ 34 2 3 h 81 4 1 n 362 q 10245 5 7 k 83 j 125 3 m 252 4 1 ¼ ð32a 5 Þ5 2 3 Fractional indices b 8 e 1024 3 35 Evaluate each expression. a 4 2 32a 5 ¼ 27 k 3 2 Exercise 5-07 1 2 2 3 3 ¼ 16 r ¼ 8r c h 179 5 See Example 14 pffiffiffiffiffiffi c 6 x18 1ffiffiffiffiffiffi d p 4 16 y 1ffiffiffiffiffi g p 4 3 n 1ffiffiffiffiffi h p 3 4 n qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 5 ð32d 10 Þ3 c pffiffiffiffiffiffiffiffiffiffiffi3 d 64m8 1 g pffiffiffiffiffiffi ffi 4 3 8s6 h 3 k ð49p4 q10 Þ2 l 1 ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi ffi p 5 1024x15 1000x 3 y 6 See Example 15 2 23 SAMPLE CHAPTER 9780170193085 201 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled Chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 Indices Worksheet Index laws review 5-08 Summary of the index laws MAT09NAWK10054 Puzzle sheet Indices squaresaw MAT09NAPS10055 Homework sheet Indices 2 MAT09NAHS10006 Summary am 3 an ¼ amþn m a m 4 a n ¼ aa n ¼ a mn a0 ¼ 1 ða m Þn ¼ a m 3 n an ¼ a1n 1 a ¼ ba b n n n a ¼ ba ¼ ba n b pffiffiffiffiffiffi m pffiffiffi m a n ¼ ð n aÞ or n a m a1 ¼ 1a ðabÞn ¼ a n b n n a ¼ an b bn pffiffiffi 1 pffiffiffi 1 pffiffiffi 1 a 2 ¼ a, a 3 ¼ 3 a, a n ¼ n a Exercise 5-08 Summary of the index laws 1 Simplify each expression. a a4 3 a 3 b t8 3 t f (g 3)6 e (w 2)4 12 i 30c 8 j (5b4)4 5c 2 Evaluate each expression. a 40 e (2)3 b (4)0 f (3)2 i (72)0 j 45 4 42 c n8 4 n2 d p3 4 p g 2b 2 3 3b 5 h 4d 7 3 5d 6 k 24m6 4 8m4 l c 7 3 20 g (5 2)2 d (7 3 2)0 h 2 4 3 23 k 42 4 45 0 m 5 2 4 50 n 102 4 10 2 o 1 2 3 Evaluate each expression, giving your answers in fraction form. b 25 c 201 a 52 l (3a)2 10 3 4 10 3 p 102 3 10 2 SAMPLE CHAPTER 202 d 103 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled N E W C E N T U R Y M AT H S A D V A N C E D for the A ustralian Curriculum 4 Evaluate each expression. 1 1 b 27 3 þ 40 a 16 2 1 1 e ð82 Þ3 f ð 9 3 Þ2 1 5 c 25 2 3 3 g 81 4 h ð32Þ5 b 8a 2w 2 3 5a 3w 7 c (4a 2b 5)4 d f 6c 2d 0 g 48u 5 v 4 16uv 4 7x 2 y 6 2 k 3 35x 5 y 3 3 1 m (2p 3q2)5 n o 2n0 7n 6 Simplify each expression using a positive index. i (4n2t)3 j a 87 e (5b)2 i 11t3 b 35 f 5b2 j (11t)3 c y1 g (ab)1 k p 3q5 m 8u3v4 n 2r6y5 o 10e1f 3 7 Simplify each expression. 1 1 7 a b 5 4 2 1 1 r 1 e f 8 10p 8 Write each expression using a negative index. 1 1 a 3 b 2 4 1 9 f e k k4 9 Simplify each expression. b d 3 3 d 7 a q 5 3 q2 e 5g 3 3 6g1 f 8a2 3 3a 3 5t 3 10t1 10 Write each expression using a fractional index. pffiffiffi pffiffiffi a 5 b 3d qffiffiffiffiffiffiffiffiffiffi pffiffiffi 2 3 p e f ðxyÞ5 i 48q 4 3q2 j 11 Simplify each expression. 3 2 4 b ð8c 3 Þ3 a 5a 2 3 49 2 a3 b9 3 e f d2 c6 2 p ffiffiffiffiffiffiffiffiffiffiffiffi 1 5 10 j i 32m 3g 2 Stage 5.3 1 d 83 þ 42 5 Simplify each expression. a (3mn3)2 3 4 e 5 9 1 2 3 1 6y g z c 1 10 4 1 g 7 x 20p 3 q 8 5p 2 q 6 2 3x h 10 5 2 p l 9y p ða 2 bÞ4 3 a3 b5 d x3 h ab1 i mw3 p 1 k 4 n7 2 1 1 7 1 2 h 5a d 1 92 5 h 3 p c d c m6 4 m 5 d t 4 t1 g 7x2 3 4x h k 2(b1)4 l (3h)2 pffiffiffiffiffi 3y qffiffiffiffiffiffiffiffiffiffiffi 4 g ð5aÞ3 ffiffiffiffiffi p 4 10 qffiffiffi5 y h 6 c 10 2 c 7m ffiffiffiffiffiffiffiffiffiffiffiffiffi p g 4 625m6 5 64p1 16p 2 Stage 5.3 d Worked solutions Exercise 5-08 MAT09NAWS10508 d 5 ð25w 5 Þ2 h 64 y3 2 2a3 c2 3 4 SAMPLE CHAPTER 9780170193085 k ð16x 8 Þ4 l 203 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:33 User ID: elangok 1BlackLining Disabled Chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 Indices 5-09 Significant figures NSW Worksheet Significant figures MAT09NAWK10058 A way of rounding a number is to give the most relevant or important digits of the number. For example, a crowd of 47 321 people can be written as 47 000, which is rounded to the nearest thousand, or to two significant figures. The first significant figure in a number is the first non-zero digit. For example, the significant figures are shown in bold in this table: First significant digit 4 4 1 2 Number 47 321 47 000 0.000 159 2 0.000 2 • • • • FPO Number of significant digits 5 2 4 1 When rounding to significant figures, start counting from the first digit that is not 0. If it is a large number, you may need to insert 0s at the end as placeholders. Zeros at the end of a whole number or at the beginning of a decimal are not significant: they are necessary placeholders. Zeros between significant figures or at the end of a decimal are significant. For example, the significant figures are shown in bold in this table. Number 809 000 0.020 70 First significant digit 8 2 Example Number of significant digits 3 4 16 State the number of significant figures in each number. a 63.70 b 0.003 05 c 7600 Solution a The zero after 7 is significant. [ 63.70 has four significant figures. b The first significant figure is 3, and the zero between 3 and 5 is significant. [ 0.003 05 has three significant figures. c The zeros after 6 are not significant. [ 7600 has two significant figures. SAMPLE CHAPTER 204 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:34 User ID: elangok 1BlackLining Disabled N E W C E N T U R Y M AT H S A D V A N C E D for the A Example ustralian Curriculum 9 17 Round each number to three significant figures. a 56.357 b 9.249 c 548 307 Solution a 56.357 56.4 b 9.249 9.25 c 548 307 548 000 Example The zeros here are not significant, but they are placeholders that are necessary for showing the place values of the 5, 4 and 8. 18 Write each number correct to one significant figure. a 0.007 39 b 0.025 c 0.963 Solution a 0.007 39 0.007 b 0.025 0.03 Exercise 5-09 c 0.963 1 The zeros at the beginning of a decimal are not significant: they are placeholders. Significant figures 1 State the number of significant figures in each number. a 457 b 0.23 c 15 000 d 4.0004 g 0.002 07 h 89 072 i 0.040 j 76 000 000 2 Round each number to three significant figures. a 37.609 b 9435 d 2.813 e 15.99 g 1 769 000 h 385 764 See Example 16 e 0.0005 k 0.000 328 f 5000 l 169.320 See Example 17 c 168.39 f 60 522 i 10.2717 3 Write each number correct to two significant figures. a 0.0637 d 0.000 158 g 0.2795 b 0.903 e 0.007 625 h 0.018 944 See Example 18 c 0.084 55 f 0.038 71 i 0.3145 4 What is 45 067 853 rounded to 3 significant figures? Select the correct answer A, B, C or D. A 45 167 853 B 45 100 000 C 45 067 900 D 45 070 000 5 What is 0.005 605 0 rounded to 2 significant figures? Select the correct answer A, B, C or D. A 0.01 B 0.010 000 0 C 0.0056 D 0.005 600 0 6 Round each number to one significant figure. a 9.478 d 0.007 66 g 1856.78 b 57.12 e 0.5067 h 0.000 28 c 0.0367 f 10 675 i 56 239 400 7 A company makes a profit of $35 754 125. a Round the profit to the nearest million and state the number of significant figures in the answer. SAMPLE CHAPTER b Round the profit to the nearest ten million and state the number of significant figures in the answer. 9780170193085 205 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:34 User ID: elangok 1BlackLining Disabled Chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 Indices 8 Australia’s population in 2010 was 21 387 000. To how many significant figures has this number been written? 9 A total of 21 558 people attended a local football match. Express this number to three significant figures. 10 Evaluate each expression, correct to the number of significant figures shown in the brackets. a 45.6 3 8.7 2.75 3 78.32 c (63.73 27.89) 4 5.82 (2) (3) e 9:732 þ 2:765 (1) 12:27 3 15:8 1 þ 253 g (3) 0:941 0:0076 Just for the record b 15.5 9.87 4 0.24 þ 8.43 3 2.4 d 63:25 þ 76:03 (4) 55:89 89:24 f 78.91 4 (23.6 þ 94.7) h pffiffiffiffiffiffiffiffiffi 84:3 3 0:0715 (1) (2) (4) Big numbers The table below lists the names of some big numbers and their meanings. Name million billion trillion quadrillion quintillion sextillion septillion octillion nonillion decillion Numeral 106 ¼ 1 000 000 109 ¼ 1 000 000 000 1012 1015 1018 10 21 10 24 10 27 10 30 10 33 According to the Guinness Book of Records, the largest number for which there is an accepted name is the centillion, first recorded in 1852. It is equal to 10 303. What special name for the number 10100? Puzzle sheet Scientific notation puzzle MAT09NAPS10059 5-10 Scientific notation Scientific notation is a short way of writing very large or very small numbers using powers of 10. It was invented in the early twentieth century when scientists needed to describe very large values, such as astronomical distances and very small values such as the masses of atoms. SAMPLE CHAPTER 206 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:34 User ID: elangok 1BlackLining Disabled N E W C E N T U R Y M AT H S A D V A N C E D for the A ustralian Curriculum 9 Summary Numbers written in scientific notation are expressed in the form m 3 10 n where m is a number between 1 and 10 and n is an integer. Example 19 Video tutorial Express each number in scientific notation. a 764 000 000 000 b 6000 Scientific notation c 0.0008 d 0.000 000 472 MAT09NAVT10011 Solution a Use the significant figures in the number to write a value between 1 and 10: 7.64 Count how many places the decimal point moves to the right to make 764 000 000 000. 11 places or count the number of 764 000 000 000 places after the first significant figure, 7 [ 764 000 000 000 ¼ 7.64 3 1011 b Use the significant figures in the number to write a value between 1 and 10: 6 Count how many places the decimal point moves to the right to make 6000. 3 places 6000 or count the number of places after the first significant figure, 6 [ 6000 ¼ 6 3 10 3 c Use the significant figures in the number to write a value between 1 and 10: 8 Count how many places the decimal point moves to the left to make 0.0008. 4 places 0.0008 or count the number of decimal places to the first significant figure, 8 [ 0.0008 ¼ 8 3 104 Note that small numbers are written with negative powers of 10. d Use the significant figures in the number to write a value between 1 and 10: 4.72 Count the number of places the decimal point moves to the left to make 0.000 000 472. 7 places or count the number of decimal places to the first significant figure, 4 SAMPLE CHAPTER 0.000 000 472 0.000 000 472 ¼ 4.72 3 107 9780170193085 207 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:34 User ID: elangok 1BlackLining Disabled Chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 Indices Example 20 Express each number in decimal form. a 2.7 3 10 4 b 3.56 3 102 Solution a 2.7 × 10 4 = 2.7000 Move the decimal point 4 places to the right. b 3.56 × 10 –2 = 0.0356 Move the decimal point 2 places to the left. = 27000 = 0.0356 Example 21 a Which number is the larger: 3.65 3 1012 or 8.1 3 1012? b Write these numbers in ascending order: 4.3 3 10 6, 2.8 3 107, 1.9 3 107 Solution To compare numbers in scientific notation, first compare the powers of ten. If the powers of ten are the same, then compare the decimal parts. a The powers of ten are the same. Compare the decimal parts: 8.1 > 3.65. [ The larger number is 8.1 3 1012 b Compare the powers of ten: 10 6 < 107. Then compare the two numbers with 107: 1.9 < 2.8. [ The numbers in ascending order are 4.3 3 10 6, 1.9 3 107, 2.8 3 107. Exercise 5-10 See Example 19 1 Express each number in scientific notation. a e i m q u 2 Scientific notation 2400 7.8 3 000 000 000 0.035 0.000 003 0.000 000 1 b f j n r v 786 000 348 000 000 80 0.000 076 0.913 0.000 89 c g k o s w 55 000 000 59 670 763 0.8 0.000 007 146 0.000 000 078 d h l p t x 95 15 10 0.0713 0.009 0.1 Express each measurement in scientific notation. a The world’s largest mammal is the blue whale, which can weigh up to 130 000 kg. b The diameter of an oxygen molecule is 0.000 000 29 cm. SAMPLE CHAPTER c The thickness of a human hair is 0.000 08 m. d Light travels at a speed of 300 000 000 m/s. 208 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:34 User ID: elangok 1BlackLining Disabled N E W C E N T U R Y M AT H S A D V A N C E D for the A ustralian Curriculum 9 e The nearest star to Earth, excluding the Sun, is Alpha Centauri, which is 40 000 000 000 000 km away. f The thickness of a typical piece of paper is 0.000 12 m. g The small intestine of an adult is approximately 610 cm long. h The diameter of a hydrogen atom is 0.000 000 0001 m. i The diameter of our galaxy, the Milky Way, is 770 000 000 000 000 000 000 m. j A microsecond means 0.000 001 s. k The Andromeda Galaxy is the most remote body visible to the naked eye, at a distance of 2 200 000 light years away. 3 4 Express each number in decimal form. b 7.1 3 10 3 a 6 3 10 5 0 d 3.14 3 10 e 6 3 105 8 g 3.02 3 10 h 5.9 3 1010 4 j 4 3 10 k 5 3 10 3 m 8.03 3 101 n 6.32 3 10 4 7 p 2.2 3 10 q 9.0 3 106 See Example 20 c f i l o r 8 3.02 3 10 7.1 3 103 1.1 3 1012 4.76 3 104 1.6 3 102 1.11 3 101 For each pair of numbers, write the larger one. a c e g i 5 5 3 3 10 or 4 3 10 8.4 3 100 or 1.3 3 107 9.3 3 109 or 7.6 3 109 3.04 3 100 or 3.04 3 104 2 3 1015 or 2 3 1017 See Example 21 b d f h j 5 6 8.4 3 10 or 2.7 3 10 3.6 3 107 or 6.3 3 107 3.5 3 106 or 9.3 3 10 2 4.5 3 105 or 3.7 3 107 6.23 3 105 or 9.7 3 105 SAMPLE CHAPTER 9780170193085 209 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:35 User ID: elangok 1BlackLining Disabled Chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 Indices 5 Write each set of numbers in ascending order. a 3.8 3 109, 7.3 3 109, 5.5 3 109 b 2.2 3 104, 5.8 3 106, 7 3 104 c 3.5 3 100, 5.3 3 10 2, 4.9 3 10 2 6 Write each set of numbers in descending order. a 6 3 10 5, 2.9 3 10 2, 1 3 10 2 b 1.2 3 109, 6.3 3 10 2, 8.1 3 104 c 4.1 3 101, 9.5 3 101, 6.4 3 103 Worksheet Scientific notation problems MAT09NAWK10060 Homework sheet Indices 3 MAT09NAHS10007 Homework sheet 5-11 Scientific notation on a calculator To enter a number in scientific notation on a calculator, use the Example or key. 22 Evaluate each expression using scientific notation. a (4.25 3 107) 3 (8.2 3 106) b (1.08 3 1015) 4 (3 3 1011) c (4.9 3 107)2 Indices revision MAT09NAHS10008 Solution a Enter 4.25 × 7 8.2 7 6 = 6 (4.25 3 10 ) 3 (8.2 3 10 ) ¼ 3.485 3 1014 − b Enter 1.08 15 ÷ 3 11 (1.08 3 1015) 4 (3 3 1011) ¼ 3.6 3 1027 c Enter 4.9 7 = = Note that with scientific notation on a calculator, there is no need to enter brackets ) around the ( numbers. 7 2 (4.9 3 10 ) ¼ 2.401 3 1015 Example 23 Estimate the value of each expression in scientific notation, then evaluate it correct to three significant figures. 9 a 9:2 3 10 5 b ð8:5 3 10 4 Þ 3 ð6:3 3 107 Þ c ð6:08 3 10 3 Þ2 2:7 3 10 Solution Estimate 9:2 3 10 9 9 3 10 9 a 2:7 3 10 5 3 3 10 5 9 ¼ 9 3 10 5 3 10 ¼ 3 3 10 4 Calculated answer 9:2 3 10 9 ¼ 34 074:074 07 2:7 3 10 5 34 000 SAMPLE CHAPTER 210 ¼ 3:4 3 10 4 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:35 User ID: elangok 1BlackLining Disabled N E W C E N T U R Y M AT H S A D V A N C E D for the A Estimate b ð8:5 3 10 4 Þ 3 ð6:3 3 107 Þ ustralian Curriculum 9 Calculated answer ð8:5 3 10 4 Þ 3 ð6:3 3 107 Þ ¼ 5:355 3 1012 5:36 3 1012 ð9 3 10 4 Þ 3 ð6 3 107 Þ ¼ ð9 3 6Þ 3 ð10 4 3 107 Þ ¼ 54 3 1011 ¼ 5:4 3 10 3 1011 ¼ 5:4 3 1012 ð6:08 3 10 5 Þ3 ¼ 2:24755 . . . 3 1017 c ð6:08 3 10 5 Þ 3 ð6 3 10 5 Þ3 2:25 3 1017 ¼ 6 3 3 ð10 5 Þ3 ¼ 216 3 1015 ¼ 2:16 3 10 2 3 1015 ¼ 2:16 3 1017 Exercise 5-11 Scientific notation on a calculator 1 Evaluate each expression using scientific notation. b (8 3 107) 4 (4 3 10 2) a (2 3 10 3) 3 (3 3 10 5) pffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi d 9 3 1012 c (2 3 10 5)3 7 8 f (1 3 108) 4 (2 3 10 3) e (4 3 10 ) 3 (6 3 10 ) 3 5 g (4 3 10 ) h 24.08 4 (8 3 106) pffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi j (2 3 10 5)2 i 3:969 3 1019 p ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi ffi 9 l 7:62 3 10 k 3 8 3 109 2 3 104 2 Estimate the value of each expression in scientific notation, then evaluate correct to three significant figures. a c e g (5.7 3 10 3) 3 (2.3 3 10 5) (9.1 3 10 20) 4 (3.2 3 10 5) (7.13 3 1010) 3 (9.8 3 108) (5.85 3 10 4)3 b d f h See Example 22 See Example 23 (8 3 10 5) 3 (3.7 3 107) (1.2 3 108)2 (1.9 3 1011) 4 (2.1 3 107) (6 3 1012) 4 (2.8 3 10 3) 3 The human body consists of approximately 6 3 109 cells, and each cell consists of 6.3 3 109 atoms. Roughly how many atoms are there in a human body? Worked solutions Exercise 5-11 MAT09NAWS10511 SAMPLE CHAPTER 9780170193085 211 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:35 User ID: elangok 1BlackLining Disabled Chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 Indices 4 A telephone book is 4.5 cm thick. There are 2000 pages in it. Find the thickness, in millimetres, of one page in scientific notation. 5 Evaluate each expression in scientific notation, correct to two significant figures. pffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi a (7.4 3 10 30) (3.59 3 10 29) b (1.076 3 1017) þ (2.3 3 1016) c 6:6 3 1027 pffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi d (7.5 3 10 23) 4 (3.3 3 1013) e (8.17 3 1016)3 f 2:69 3 1045 ð5:6 3 10 4 Þ 3 ð3:9 3 105 Þ ð2:3 3 107 Þ g (7.05 3 10 3) 4 (3.9 3 107) h j 5 20 m 99 k 8011 n (0.7)5 i 1595 3 1959 l 310 Express the answers for questions 6 to 10 in scientific notation correct to two significant figures if necessary. Worked solutions Exercise 5-11 MAT09NAWS10511 6 The Earth is 1.50 3 108 km from the Sun and the speed of light is 3 3 10 5 km/s. How long does it take for light to travel from the Sun to Earth? Express your answer in: a seconds b minutes. 7 The Sun burns 6 million tonnes of hydrogen a second. Calculate how many tonnes of hydrogen it burns in a year (that is, 365.25 days). 8 Sound travels at approximately 330 metres per second. If Mach 1 is the speed of sound, how fast is Mach 5? Convert your answer to kilometres per second. 9 The distance light travels in one year is called a light year. If the speed of light is approximately 3 3 10 5 km per second, how far does light travel in a leap year? 10 A thunderstorm is occurring 30 km from where you are standing. Use the speed of light (3 3 10 5 km per second) and the speed of sound (330 metres per second) to calculate in seconds: a how long the light from the lightning takes to reach you b how long the sound from the thunder takes to reach you. 11 a What is the largest number that can be displayed on your calculator? b What is the smallest number that can be displayed? SAMPLE CHAPTER 212 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:36 User ID: elangok 1BlackLining Disabled N E W C E N T U R Y M AT H S A D V A N C E D for the A ustralian Curriculum 9 Investigation: A lifetime of heartbeats How many times does your heart beat in an average lifetime of 80 years? 1 Work in pairs and copy this table. Name Trial 1 Trial 2 Average beats per minute 2 Use two fingers to measure your pulse. Have your partner time you for a minute. Do this twice, record your results in the table and find the average. 3 Repeat Step 2 for your partner. 4 Calculate how many times your heart (and your partner’s heart) beats in the following periods. Write your answers in scientific notation correct to two significant figures. a an hour b a day c a week d a year (use 365.25 days) e an average lifetime of 80 years Just for the record Straight hair • round follicle Hairy numbers Wavy hair oval follicle Curly hair flat follicle There are about 110 000 hairs on your head. Each hair grows at the rate of about 1.3 3 103 cm per hour. A single hair lasts about six years. Every day you lose between 30 and 60 hairs. Each hair grows from a small depression in the skin called a follicle (a gland). After the hair falls out, the follicle rests for about three to four months before the next hair starts growing. Hair follicles are either oval, flat or round in shape. How straight, wavy or curly your hair is depends on the shape of your hair follicles. How many hairs are on all the heads in China if its population is approximately 1.435 3 109? Answer in both scientific notation and decimal notation. SAMPLE CHAPTER 9780170193085 213 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:36 User ID: elangok 1BlackLining Disabled Chapter 1 2 3 4 5 6 7 8 9 10 11 12 13 Indices Power plus Worksheet 1 Write each number in scientific notation. a 438.2 3 109 d 2013 3 103 g 6.7 millionths Binary number system MAT09NAWK10057 2 3 c 0.0004 3 1012 f 57.8 thousandths i 3.2 billionths b 0.52 3 107 e 57.8 thousand h 3.2 billion Evaluate each expression. pp ffiffiffiffiffiffiffiffiffiffiffi pp ffiffiffiffiffiffiffiffiffi ffiffiffiffiffiffiffiffi ffiffiffiffiffi 81 a b 625 qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi ffi p pffiffiffiffiffiffiffiffiffiffiffiffiffiffi ffiffiffiffiffiffiffiffiffiffiffi ffi pffiffiffiffiffiffiffiffiffiffi 4 pffiffiffiffiffiffiffi e 6561 f 256 qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi pp ffiffiffiffiffiffiffiffiffiffiffi ffiffiffiffiffiffiffiffi 256 pffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi p 3 1 000 000 g c Find values of a, m and n so that each equation is true. m m m b an ¼ 3 c a n ¼ 64 a an ¼ 2 pffiffiffiffiffiffiffiffiffiffiffiffiffiffi p ffiffiffiffiffiffiffiffiffiffi 5 1024 p ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi ffi 3 pffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 1 000 000 h d m d a n ¼ 125 4 For how many values of a and b does ab ¼ ba? 5 The terms in the pattern 3, 5, 17, 257, 65 537,… can all be generated by a simple method, using only the numbers 1 and 2. a What is this method? b What is the next number in the sequence? SAMPLE CHAPTER 214 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:36 User ID: elangok 1BlackLining Disabled Chapter 5 review n Language of maths Puzzle sheet ascending base descending estimate expanded form exponent fractional power index index laws index notation indices negative power power product quotient reciprocal scientific notation significant figures term zero power Indices crossword MAT09NAPS10061 1 What does a power of 12 mean? 2 Which two words from the list mean ‘power’? 3 What is the or key on a calculator used for? 4 What is the index law for dividing terms with the same base? 5 Which digits in 0.006 701 are significant figures? 6 What power is associated with the reciprocal of a term or number? 7 What type of numbers when written in scientific notation have negative powers of 10? n Topic overview • • • • • • What was this topic about? What was the main theme? What content was new and what was revision? What are the index laws? Write 10 questions (with solutions) that could be used in a test for this chapter. Include some questions that you have found difficult to answer. List the sections of work in this chapter that you did not understand. Follow up this work with a friend or your teacher. Worksheet Mind map: Indices MAT09NAWK10063 Copy and complete this mind map of the topic, adding detail to its branches and using pictures, symbols and colour where needed. Ask your teacher to check your work. Multiplying and dividing terms with the same base Scientific notation Powers of products and quotients Power of a power INDICES Index or power Base Zero and negative indices SAMPLE CHAPTER Significant figures 9780170193085 Fractional indices 215 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:36 User ID: elangok 1BlackLining Disabled Chapter 5 revision See Exercise 5-01 See Exercise 5-02 1 Simplify each expression, writing the answer in index notation. b 420 4 44 c a 10 3 3 107 8 2 d h 3h e 3n3 3 4n f g 20m9 4 4m h 3v4w 2 3 2v 3w 5 i 6 10 8 8 p q j 24t4 h2 k 2 2 l 3t h p q 2 Simplify each expression, writing the answer in index notation. a (22)3 d (2y 3)10 g ð2Þ5 See Exercise 5-03 3 Simplify each expression. a (ab 2)4 d (4h2g)3 5 g 3m 2 See Exercise 5-04 b (k 5)5 e (5t 2)2 h ð2k Þ5 c (x)4 f (10g)3 i ð5m3 Þ2 b (5x 3y 2)2 4 e a 7 c (4t 2)3 f (2pqr)5 4 2a7 i b h (3np2)4 8 6 3 b y k 8b 2 y j (4t 4u 5)3 3 8t 2u 4 Simplify each expression. a 70 l 45c6d 8 4 (3cd 2)2 b (7)0 c e0 d (e)0 See Exercise 5-05 e e0 0 2p h g (gh)0 3 5 Simplify each expression using a positive index. b 192 c x1 a 83 e (4m)1 See Exercise 5-05 Stage 5.3 See Exercise 5-05 See Exercise 5-06 See Exercise 5-07 f (4m)2 g 1 3 i 2x4 j k 5a 6 Write each expression using a negative index. a 13 b 15 c 10 r 2 using a positive index. 7 Simplify 8 3x 8 Write each expression using a radical (root) sign. 1 1 b u2 c a q3 3 2 216 i 2p0 3 d p5 (5b)1 h 5b1 100 1 l 9 c4d 2 1 r d 3 b 1 1 ð2qÞ3 d ðarÞ2 3 c 362 b ð32Þ5 10 Simplify each expression. 4 a ð125d 15 Þ3 See Exercise 5-09 f g0h 9 Evaluate each expression. a 64 3 See Exercise 5-07 a12 4 a 2 10d 15 4 5d 3 5x 5y 2 3 3xy 100a 2 b4 5ab 2 1 b ð16y 20 Þ4 2 c ð32x 8 Þ5 d p ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi 3 64n12 11 Round each value correct to the number of significant figures shown in the brackets. a 8.5678 (2) b 15 712 (3) c 476 (1) d 0.007 126 6 (4) e 0.9041 (3) f 301 378 (2) g 4805.28 (3) h 0.000 87 (1) i 67 000 000 (1) SAMPLE CHAPTER 9780170193085 Path: K:/CLA-NCM_09A-13-0303/Application/CLA-NCM_09A-13-0303005.3d Date: 6th May 2013 Time: 16:36 User ID: elangok 1BlackLining Disabled Chapter 5 revision 12 Express each number in scientific notation. a 37 000 b 0.61 d 0.000 49 e 13 c 250 000 f 0.000 000 000 08 13 Express each number in decimal form. b 6 3 107 a 8.1 3 10 3 d 8.1 3 103 e 6 3 107 c 3.075 3 100 f 3.075 3 102 See Exercise 5-10 See Exercise 5-10 14 Write these numbers in ascending order: 3 3 10 3, 9.1 3 108, 2.4 3 10 3. See Exercise 5-10 15 Evaluate each expression using scientific notation. 22 8 a (3.65 3 10 ) 3 (7.4 3 10 ) c (5 3 10 5)3 See Exercise 5-11 10 4 b p (1.44 3 10 )ffi 4 (3.6 3 10 ) ffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi d 6:25 3 108 16 Estimate the value of each expression in scientific notation, then evaluate correct to two significant figures. a (8.9 3 109) 3 (1.1 3 107) b (9.3 3 1015) 3 (4 3 10 2) See Exercise 5-09 c (3.1 3 10 4)2 SAMPLE CHAPTER 9780170193085 217