Haese and Harris Publications specialists in mathematics publishing Endorsed by University of Cambridge International Examinations IGCSE Cambridge International Mathematics (0607) Extended Keith Black Alison Ryan Michael Haese Robert Haese Sandra Haese Mark Humphries 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 IGCSE01 cyan magenta yellow black Y:\HAESE\IGCSE01\IG01_00\001IGCSE01_01.CDR Thursday, 30 October 2008 4:36:42 PM PETER IGCSECAMBRIDGEINTERNATIONALMATHEMATICS(0607) KeithBlack B.Sc.(Hons.),Dip.Ed. AlisonRyan B.Sc.,M.Ed. MichaelHaese B.Sc.(Hons.),Ph.D. RobertHaese B.Sc. SandraHaese B.Sc. MarkHumphries B.Sc.(Hons.) Haese&HarrisPublications 3FrankCollopyCourt,AdelaideAirport, SA5950,AUSTRALIA Telephone: +618 83559444, Fax: +618 83559471 Email: [email protected] Web: www.haeseandharris.com.au NationalLibraryofAustraliaCardNumber&ISBN 978-1-921500-04-6 ©Haese&HarrisPublications2009 PublishedbyRaksarNomineesPtyLtd 3FrankCollopyCourt,AdelaideAirport, SA5950,AUSTRALIA FirstEdition 2009 CartoonartworkbyJohnMartin.ArtworkandcoverdesignbyPiotrPoturaj. FractalartworkonthecovercopyrightbyJarosławWierny,www.fractal.art.pl ComputersoftwarebyDavidPurton,TroyCruickshankandThomasJansson. TypesetinAustraliabySusanHaeseandCharlotteSabel(RaksarNominees).TypesetinTimesRoman10/11 This textbook and its accompanying CD have been endorsed by University of Cambridge International Examinations(CIE).TheyhavebeendevelopedindependentlyoftheInternationalBaccalaureateOrganization (IBO)andarenotconnectedwithorendorsedby,theIBO. This book is copyright. Except as permitted by the Copyright Act (any fair dealing for the purposes of private study, research, criticism or review), no part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recordingorotherwise,withoutthepriorpermissionofthepublisher.EnquiriestobemadetoHaese&Harris Publications. Copyingforeducationalpurposes:WherecopiesofpartorthewholeofthebookaremadeunderPartVB oftheCopyrightAct,thelawrequiresthattheeducationalinstitutionorthebodythatadministersithasgiven a remuneration notice to CopyrightAgency Limited (CAL). For information, contact the CopyrightAgency Limited. Acknowledgements:ThepublishersacknowledgethecooperationofOxfordUniversityPress,Australia,forthe reproduction of material originally published in textbooks produced in association with Haese&HarrisPublications. Whileeveryattempthasbeenmadetotraceandacknowledgecopyright,theauthorsandpublishersapologisefor any accidental infringement where copyright has proved untraceable. They would be pleased to come to a suitableagreementwiththerightfulowner. Disclaimer:All the internet addresses (URL’s) given in this book were valid at the time of printing. While the authors and publisher regret any inconvenience that changes of address may cause readers, no responsibilityforanysuchchangescanbeacceptedbyeithertheauthorsorthepublisher. 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 IGCSE01 cyan magenta yellow black Y:\HAESE\IGCSE01\IG01_00\002IGCSE01_00.CDR Friday, 21 November 2008 12:34:38 PM PETER FOREWORD This book has been written to cover the ‘IGCSE Cambridge International Mathematics (0607) Extended’ courseoveratwo-yearperiod. ThenewcoursewasdevelopedbyUniversityofCambridgeInternationalExaminations(CIE)inconsultation with teachers in international schools around the world. It has been designed for schools that want their mathematics teaching to focus more on investigations and modelling, and to utilise the powerful technology ofgraphicscalculators. Thecoursespringsfromtheprinciplesthatstudentsshoulddevelopagoodfoundationofmathematicalskills and that they should learn to develop strategies for solving open-ended problems. It aims to promote a positive attitude towards Mathematics and a confidence that leads to further enquiry. Some of the schools consulted by CIE were IB schools and as a result, Cambridge International Mathematics integrates exceptionallywellwiththeapproachtotheteachingofMathematicsinIBschools. This book is an attempt to cover, in one volume, the content outlined in the Cambridge International Mathematics (0607) syllabus. References to the syllabus are made throughout but the book can be used as a full course in its own right, as a preparation for GCE Advanced Level Mathematics or IB Diploma Mathematics, for example.The book has been endorsed by CIE but it has been developed independently of theIndependentBaccalaureateOrganizationandisnotconnectedwith,orendorsedby,theIBO. To reflect the principles on which the new course is based, we have attempted to produce a book and CD package that embraces technology, problem solving, investigating and modelling, in order to give students different learning experiences.There are non-calculator sections as well as traditional areas of mathematics, especially algebra.An introductory section ‘Graphics calculator instructions’appears on p. 11. It is intended as a basic reference to help students who may be unfamiliar with graphics calculators. Two chapters of ‘assumedknowledge’areaccessiblefromtheCD:‘Number’and‘Geometryandgraphs’(seepp.29and30). Theycanbeprintedforthosewhowanttoensurethattheyhavetheprerequisitelevelsofunderstandingfor thecourse.Toreflectoneofthemainaimsofthenewcourse,thelasttwochaptersinthebookaredevotedto multi-topic questions, and investigations and modelling. Review exercises appear at the end of each chapter with some ‘Challenge’ questions for the more able student. Answers are given at the end of the book, followedbyanindex. The interactive CD contains Self Tutor software (see p. 5), geometry and graphics software, demonstrationsandsimulations,andthetwoprintablechaptersonassumedknowledge.TheCDalsocontains thetextofthebooksothatstudentscanloaditonahomecomputerandkeepthetextbookatschool. TheCambridgeInternationalMathematicsexaminationsareintheformofthreepapers:oneanon-calculator paper, another requiring the use of a graphics calculator, and a third paper containing an investigation and a modellingquestion.Alloftheseaspectsofexaminingareaddressedinthebook. Thebookcanbeusedasaschemeofworkbutitisexpectedthattheteacherwillchoosetheorderoftopics. Thereareafewoccasionswhereaquestioninanexercisemayrequiresomethingdonelaterinthebookbut this has been kept to a minimum. Exercises in the book range from routine practice and consolidation of basicskills,toproblemsolvingexercisesthatarequitedemanding. In this changing world of mathematics education, we believe that the contextual approach shown in this book, with the associated use of technology, will enhance the students’ understanding, knowledge and appreciationofmathematics,anditsuniversalapplication. Wewelcomeyourfeedback. Email: [email protected] Web: www.haeseandharris.com.au KB,AR,PMH,RCH,SHH,MH 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 IGCSE01 cyan magenta yellow black Y:\HAESE\IGCSE01\IG01_00\003IGCSE01_00.CDR Friday, 21 November 2008 12:53:41 PM PETER ACKNOWLEDGEMENTS The authors and publishers would like to thank University of Cambridge International Examinations (CIE) for their assistance and support in the preparation of this book. Exam questions from past CIE exam papers arereproducedbypermissionoftheUniversityofCambridgeLocalExaminationsSyndicate.TheUniversity of Cambridge Local Examinations Syndicate bears no responsibility for the example answers to questions takenfromitspastquestionpaperswhicharecontainedinthispublication. Inadditionwewouldliketothanktheteacherswhoofferedtoreadproofsandwhogaveadviceandsupport: SimonBullock,PhilipKurbis,RichardHenry,JohnnyRamesar,AlanDaykin,NigelWheeler,YenerBalkaya, andspecialthanksisduetoFranO'Connorwhogotusstarted. The publishers wish to make it clear that acknowledging these teachers, does not imply any endorsement of thisbookbyanyofthem,andallresponsibilityforthecontentrestswiththeauthorsandpublishers. 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 IGCSE01 cyan magenta yellow black Y:\HAESE\IGCSE01\IG01_00\004IGCSE01_00.CDR Friday, 21 November 2008 12:18:06 PM PETER USING THE INTERACTIVE CD TheinteractiveStudentCDthatcomeswiththisbookisdesignedforthosewho wanttoutilisetechnologyinteachingandlearningMathematics. TheCDiconthatappearsthroughoutthebookdenotesanactivelinkontheCD. SimplyclickontheiconwhenrunningtheCDtoaccessalargerangeofinteractive featuresthatincludes: • spreadsheets (cid:127) printableworksheets INTERACTIVELINK (cid:127) graphingpackages (cid:127) geometrysoftware (cid:127) demonstrations (cid:127) simulations (cid:127) printablechapters (cid:127) SELFTUTOR Forthosewhowanttoensuretheyhavetheprerequisitelevelsofunderstandingforthisnewcourse,printable chaptersofassumedknowledgeareprovidedforNumber(seep.29) andGeometryandGraphs(seep.30). SELF TUTOR is an exciting feature of this book. The Self Tutor icon on each worked example denotes an active link on the CD. Simply ‘click’ on the Self Tutor (or anywhere in the example box) to access the worked example, with a teacher’s voice explaining each step necessary to reach the answer. Play any line as often as you like. See how the basic processes come alive using movement and colour on the screen. Ideal for students who have missed lessons or need extra help. Example 8 Self Tutor Adiehasthenumbers0,0,1,1,4and5.Itisrolledtwice.Illustratethesamplespaceusing a2-Dgrid.Hencefindtheprobabilityofgetting: a a total of 5 b two numberswhich are the same. 2-Dgrid roll1 5 There are 6£6=36 possible outcomes. 4 a P(total of 5) = 8 fthose with a g 1 36 1 0 b P(same numbers) = 10 fthose circled g 0 36 roll2 0 0 1 1 4 5 SeeChapter25,Probability,p.516 GRAPHICSCALCULATORS The course assumes that each student will have a graphics calculator. An introductory section ‘Graphics calculatorinstructions’appearsonp.11.Tohelpgetstudentsstarted,thesectionincludessomebasicinstructions fortheTexasInstrumentsTI-84PlusandtheCasiofx-9860Gcalculators. 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 IGCSE01 cyan magenta yellow black Y:\HAESE\IGCSE01\IG01_00\005IGCSE01_00.CDR Friday, 21 November 2008 12:54:09 PM PETER SYMBOLS AND NOTATION USED IN THIS BOOK N thesetofpositiveintegersandzero, > isgreaterthan f0,1,2,3,......g ¸or> isgreaterthanorequalto Z thesetofintegers, f0,§1,§2,§3,......g < islessthan Z+ thesetofpositiveintegers, f1,2,3,......g ·or6 islessthanorequalto Q thesetofrationalnumbers un thenthtermofasequenceorseries Q+ thesetofpositiverationalnumbers, f : x7!y f isafunctionunderwhichxismappedtoy fxjx>0, x2Qg f(x) theimageofxunderthefunctionf R thesetofrealnumbers f¡1 theinversefunctionofthefunctionf R+ thesetofpositiverealnumbers, fxjx>0, x2Rg logax logarithmtothebaseaofx sin,cos,tan thecircularfunctions fx1,x2,....g thesetwithelements x1,x2,..... A(x,y) thepointAintheplanewithCartesian n(A) thenumberofelementsinthefinitesetA coordinatesxandy ( fxj...... thesetofallxsuchthat thelinesegmentwithendpointsAandB 2 isanelementof AB thedistancefromAtoB thelinecontainingpointsAandB 2= isnotanelementof b ? or f g theempty(null)set A theangleatA b U theuniversalset CAB theanglebetweenCAandAB [ union ¢ABC thetrianglewhoseverticesareA,BandC \ intersection v thevectorv ¡! µ isasubsetof AB thevectorrepresentedinmagnitudeanddirection bythedirectedlinesegmentfromAtoB ½ isapropersubsetof jaj themagnitudeofvectora A0 thecomplementofthesetA ¡! ¡! an1, pna atothepowerofpn1, nthrootofa jP(AAB)j tphreobmabagilnitiytuodfeeovfeAntBA (if a>0 then na>0) P(A0) probabilityoftheevent“notA” a12,pa atothepower 12,psquarerootofa x1,x2,.... observationsofavariable (if a>0 then a>0) f1,f2,.... frequencieswithwhichtheobservations jxj nthemodulusorabsolutevalueofx,thatis x1,x2,x3,..... occur xforx>0, x2R x meanofthevalues x1,x2,.... ¡xforx<0, x2R §f sumofthefrequencies f1,f2,.... ´ identity or isequivalentto r Pearson’scorrelationcoefficient ¼ isapproximatelyequalto r2 coefficientofdetermination »= iscongruentto k isparallelto isperpendicularto 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 IGCSE01 cyan magenta yellow black Y:\HAESE\IGCSE01\IG01_00\006IGCSE01_00.CDR Friday, 21 November 2008 12:06:59 PM PETER Table of contents 7 TABLE OF CONTENTS J Expressionswithfourterms 48 K Factorising xX(cid:1)+(cid:1)bx(cid:1)+(cid:1)c 49 L Splittingthemiddleterm 51 M Miscellaneousfactorisation 54 SYMBOLSANDNOTATION Reviewset1A 55 Reviewset1B 56 USEDINTHISBOOK 6 2 SETS 57 GRAPHICSCALCULATOR INSTRUCTIONS 11 A Setnotation 57 B Specialnumbersets 60 A Basiccalculations 12 C Intervalnotation 61 B Basicfunctions 13 D Venndiagrams 63 C Secondaryfunctionandalphakeys 17 E Unionandintersection 65 D Memory 17 F Problemsolving 69 E Lists 19 Reviewset2A 72 F Statisticalgraphs 21 Reviewset2B 73 G Workingwithfunctions 22 H Twovariableanalysis 26 3 ALGEBRA (EQUATIONSANDINEQUALITIES) 75 ASSUMEDKNOWLEDGE(NUMBER) 29 A Solvinglinearequations 75 A Numbertypes CD B Solvingequationswithfractions 80 B Operationsandbrackets CD C Formingequations 83 C HCFandLCM CD D Problemsolvingusingequations 85 D Fractions CD E Powerequations 87 E Powersandroots CD F Interpretinglinearinequalities 88 F Ratioandproportion CD G Solvinglinearinequalities 89 G Numberequivalents CD Reviewset3A 91 H Roundingnumbers CD Reviewset3B 92 I Time CD 4 LINES,ANGLESANDPOLYGONS 93 ASSUMEDKNOWLEDGE (GEOMETRYANDGRAPHS) 30 A Angleproperties 93 B Triangles 98 A Angles CD C Isoscelestriangles 100 B Linesandlinesegments CD D Theinterioranglesofapolygon 103 C Polygons CD E Theexterioranglesofapolygon 106 D Symmetry CD Reviewset4A 107 E Constructingtriangles CD Reviewset4B 109 F Congruence CD G Interpretinggraphsandtables CD 5 GRAPHS,CHARTSANDTABLES 111 1 ALGEBRA A Statisticalgraphs 112 (EXPANSIONANDFACTORISATION) 31 B Graphswhichcomparedata 116 C Usingtechnologytographdata 119 A Thedistributivelaw 32 Reviewset5A 120 B Theproduct(a+b)(c+d) 33 Reviewset5B 122 C Differenceoftwosquares 35 D Perfectsquaresexpansion 37 6 EXPONENTSANDSURDS 123 E Furtherexpansion 39 F Algebraiccommonfactors 40 A Exponentorindexnotation 123 G Factorisingwithcommonfactors 42 B Exponentorindexlaws 126 H Differenceoftwosquaresfactorisation 45 C Zeroandnegativeindices 129 I Perfectsquaresfactorisation 47 D Standardform 131 E Surds 134 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 IGCSE01 cyan magenta yellow black Y:\HAESE\IGCSE01\IG01_00\007IGCSE01_00.CDR Friday, 21 November 2008 12:29:38 PM PETER 8 Table of contents F Propertiesofsurds 137 C Capacity 245 G Multiplicationofsurds 139 D Mass 248 H Divisionbysurds 142 E Compoundsolids 249 Reviewset6A 143 Reviewset11A 253 Reviewset6B 145 Reviewset11B 254 7 FORMULAEANDSIMULTANEOUS 12 COORDINATEGEOMETRY 255 EQUATIONS 147 A Plottingpoints 256 A Formulasubstitution 148 B Distancebetweentwopoints 258 B Formularearrangement 150 C Midpointofalinesegment 261 C Formuladerivation 153 D Gradientofalinesegment 263 D Moredifficultrearrangements 155 E Gradientofparalleland E Simultaneousequations 158 perpendicularlines 267 F Problemsolving 164 F Usingcoordinategeometry 270 Reviewset7A 166 Reviewset12A 272 Reviewset7B 167 Reviewset12B 273 8 THETHEOREMOFPYTHAGORAS 169 13 ANALYSISOFDISCRETEDATA 275 A Pythagoras’theorem 170 A Variablesusedinstatistics 277 B TheconverseofPythagoras’theorem 176 B Organisinganddescribingdiscretedata 278 C Problemsolving 177 C Thecentreofadiscretedataset 282 D Circleproblems 181 D Measuringthespreadofdiscretedata 285 E Three-dimensionalproblems 185 E Datainfrequencytables 288 Reviewset8A 187 F Groupeddiscretedata 290 Reviewset8B 188 G Statisticsfromtechnology 292 Reviewset13A 293 9 MENSURATION Reviewset13B 295 (LENGTHANDAREA) 191 14 STRAIGHTLINES 297 A Length 192 B Perimeter 194 A Verticalandhorizontallines 297 C Area 196 B Graphingfromatableofvalues 299 D Circlesandsectors 201 C Equationsoflines Reviewset9A 206 (gradient-interceptform) 301 Reviewset9B 207 D Equationsoflines(generalform) 304 E Graphinglinesfromequations 307 10 TOPICSINARITHMETIC 209 F Linesofsymmetry 308 Reviewset14A 310 A Percentage 209 Reviewset14B 311 B Profitandloss 211 C Simpleinterest 214 15 TRIGONOMETRY 313 D Reversepercentageproblems 217 E Multipliersandchainpercentage 218 A Labellingsidesofarightangledtriangle 314 F Compoundgrowth 222 B Thetrigonometricratios 316 G Speed,distanceandtime 224 C Problemsolving 322 H Travelgraphs 226 D Thefirstquadrantoftheunitcircle 327 Reviewset10A 228 E Truebearings 330 Reviewset10B 229 F 3-dimensionalproblemsolving 331 Reviewset15A 336 11 MENSURATION Reviewset15B 337 (SOLIDSANDCONTAINERS) 231 16 ALGEBRAICFRACTIONS 339 A Surfacearea 231 B Volume 239 A Simplifyingalgebraicfractions 339 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 IGCSE01 cyan magenta yellow black Y:\HAESE\IGCSE01\IG01_00\008IGCSE01_00.CDR Friday, 7 November 2008 9:47:47 AM PETER Table of contents 9 B Multiplyinganddividingalgebraic E Graphsofquadraticfunctions 431 fractions 344 F Axesintercepts 438 C Addingandsubtractingalgebraic G Lineofsymmetryandvertex 441 fractions 346 H Findingaquadraticfunction 445 D Morecomplicatedfractions 348 I Usingtechnology 446 Reviewset16A 351 J Problemsolving 447 Reviewset16B 352 Reviewset21A 451 Reviewset21B 453 17 CONTINUOUSDATA 353 22 TWOVARIABLEANALYSIS 455 A Themeanofcontinuousdata 354 B Histograms 355 A Correlation 456 C Cumulativefrequency 359 B Lineofbestfitbyeye 459 Reviewset17A 364 C Linearregression 461 Reviewset17B 365 Reviewset22A 466 Reviewset22B 467 18 SIMILARITY 367 23 FURTHERFUNCTIONS 469 A Similarity 367 B Similartriangles 370 A Cubicfunctions 469 C Problemsolving 373 B Inversefunctions 473 D Areaandvolumeofsimilarshapes 376 C Usingtechnology 475 Reviewset18A 380 D Tangentstocurves 480 Reviewset18B 381 Reviewset23A 481 Reviewset23B 481 19 INTRODUCTIONTOFUNCTIONS 383 24 VECTORS 483 A Mappingdiagrams 383 B Functions 385 A Directedlinesegmentrepresentation 484 C Functionnotation 389 B Vectorequality 485 D Compositefunctions 391 C Vectoraddition 486 E Reciprocalfunctions 393 D Vectorsubtraction 489 F Theabsolutevaluefunction 395 E Vectorsincomponentform 491 Reviewset19A 398 F Scalarmultiplication 496 Reviewset19B 399 G Parallelvectors 497 H Vectorsingeometry 499 20 TRANSFORMATIONGEOMETRY 401 Reviewset24A 501 Reviewset24B 503 A Translations 402 B Rotations 404 25 PROBABILITY 505 C Reflections 406 D Enlargementsandreductions 408 A Introductiontoprobability 506 E Stretches 410 B Estimatingprobability 507 F Transformingfunctions 413 C Probabilitiesfromtwo-waytables 510 G Theinverseofatransformation 416 D Expectation 512 H Combinationsoftransformations 417 E Representingcombinedevents 513 Reviewset20A 419 F Theoreticalprobability 515 Reviewset20B 420 G Compoundevents 519 H Usingtreediagrams 522 21 QUADRATICEQUATIONSAND I Samplingwithandwithoutreplacement 524 FUNCTIONS 421 J Mutuallyexclusiveand non-mutuallyexclusiveevents 527 A Quadraticequations 422 K Miscellaneousprobabilityquestions 528 B TheNullFactorlaw 423 Reviewset25A 530 C Thequadraticformula 427 Reviewset25B 531 D Quadraticfunctions 429 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 IGCSE01 cyan magenta yellow black Y:\HAESE\IGCSE01\IG01_00\009IGCSE01_00.CDR Friday, 7 November 2008 9:48:16 AM PETER 10 Table of contents 26 SEQUENCES 533 C Rulesforlogarithms 629 D Logarithmsinbase10 630 A Numbersequences 534 E Exponentialandlogarithmicequations 634 B Algebraicrulesforsequences 535 Reviewset31A 636 C Geometricsequences 537 Reviewset31B 637 D Thedifferencemethodforsequences 539 Reviewset26A 544 32 INEQUALITIES 639 Reviewset26B 545 A Solvingonevariableinequalitieswith 27 CIRCLEGEOMETRY 547 technology 639 B Linearinequalityregions 641 A Circletheorems 547 C Integerpointsinregions 644 B Cyclicquadrilaterals 556 D Problemsolving(Extension) 645 Reviewset27A 561 Reviewset32A 647 Reviewset27B 562 Reviewset32B 648 28 EXPONENTIALFUNCTIONSAND 33 MULTI-TOPICQUESTIONS 649 EQUATIONS 565 A Rationalexponents 566 34 INVESTIGATIONANDMODELLING B Exponentialfunctions 568 QUESTIONS 661 C Exponentialequations 570 A Investigationquestions 661 D Problemsolvingwith B Modellingquestions 669 exponentialfunctions 573 E Exponentialmodelling 576 ANSWERS 673 Reviewset28A 577 Reviewset28B 578 INDEX 752 29 FURTHERTRIGONOMETRY 579 A Theunitcircle 579 B Areaofatriangleusingsine 583 C Thesinerule 585 D Thecosinerule 588 E Problemsolvingwiththesine andcosinerules 591 F Trigonometrywithcompoundshapes 593 G Trigonometricgraphs 595 H Graphsofy(cid:1)=(cid:1)a(cid:1)sin(bx)andy(cid:1)=(cid:1)a(cid:1)cos(bx) 599 Reviewset29A 601 Reviewset29B 602 30 VARIATIONAND POWERMODELLING 605 A Directvariation 606 B Inversevariation 612 C Variationmodelling 615 D Powermodelling 619 Reviewset30A 622 Reviewset30B 623 31 LOGARITHMS 625 A Logarithmsinbasea 625 B Thelogarithmicfunction 627 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 0 5 25 50 75 95 100 IGCSE01 cyan magenta yellow black Y:\HAESE\IGCSE01\IG01_00\010IGCSE01_00.CDR Friday, 21 November 2008 12:30:32 PM PETER