58
Section 1.1 - Number Systems 5 Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher. In this course, we will work with many number systems. We will solve problems involving profit and loss, time expressed as fractions, lengths of triangles expressed as square roots, and more. In this section, we will look at numbers that are part of a larger collection of numbers called the real numbers. Natural Numbers: 1, 2, 3... " , Whole Numbers: 0, 1, 2, 3... " , Integers: ... 3, 2, 1, 0, 1, 2, 3... - - - " , Rational Numbers: All the numbers that can be written as a fraction with the denominator not equal to zero. Examples: 3, 0, 5, 3 2 , , . , . 7 10 2 35 2 35 - - - Irrational Numbers: All the numbers that cannot be written as a fraction, a terminating decimal, or a repeating decimal. Examples: , , . ... 2 1 62789 r Real Numbers: All the rational numbers and irrational numbers combined. To which number systems do the following numbers belong? , , , , , 2041 3 2 2 r - $ . Solution: Natural numbers: 4 Whole numbers: 0, 4 Integers: − 2, 0, 4 Rational numbers: − 2, 0, 4, 1 3 2 Irrational numbers: 2 , r Real numbers: − 2, 0, 4, 1 3 2 , 2 , r Natural Numbers Whole Numbers Integers Rational Numbers Real Numbers Irrational Numbers Example 1 Number Systems 1.1 Lambrick Park Secondary

Lambrick Park Secondary 1.1 Number Systems

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Section 1.1 - Number Systems ♦ 5

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Inthiscourse,wewillworkwithmanynumbersystems.Wewillsolveproblemsinvolvingprofitandloss,time expressedasfractions,lengthsoftrianglesexpressedassquareroots,andmore.

Inthissection,wewilllookatnumbersthatarepartofalargercollectionofnumberscalledthereal numbers.

Natural Numbers: 1,2,3..." ,

Whole Numbers: 0,1,2,3..." ,

Integers: ... 3, 2, 1,0,1,2,3...- - -" ,

Rational Numbers: Allthenumbersthatcanbewrittenasafractionwiththedenominatornotequaltozero.

Examples: 3, 0, 5,32, , . , .710 2 35 2 35- - -

Irrational Numbers: Allthenumbersthatcannotbewrittenasafraction,aterminatingdecimal,ora repeatingdecimal.

Examples: , , . ...2 1 62789r

Real Numbers: Alltherationalnumbersandirrationalnumberscombined.

Towhichnumbersystemsdothefollowingnumbersbelong?

, , , , ,2 0 4 132 2 r-$ .

►Solution: Naturalnumbers: 4 Wholenumbers: 0,4 Integers: −2,0,4 Rationalnumbers: −2,0,4,1

32

Irrationalnumbers: 2 ,r Realnumbers: −2,0,4,1

32 , 2 ,r

NaturalNumbers

WholeNumbers

Integers

RationalNumbers

RealNumbers

IrrationalNumbers

Example 1

Number Systems1.1

Lambrick Park Secondary

6 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

1.1 Exercise Set

1. Statewhethereachstatementistrueorfalse.

a) Everynaturalnumberispositive. b) Everywholenumberispositive.

c) Everyintegerisawholenumber. d) Everywholenumberisaninteger.

e) Everyrealnumberisarationalnumber. f) Everyintegerisarationalnumber.

g) Everydecimalnumberisarationalnumber. h) Zeroisarationalnumber.

i) Allrealnumbersareintegers. j) Allintegersarerealnumbers.

k) Allwholenumbersarerealnumbers. l) Thereciprocalofanon-zerointegerisalsoaninteger.

m) Thereciprocalofanon-zerorationalnumberis n) Anirrationalnumbertimesadifferentirrational alsoarationalnumber. numbercouldberational.

o) Everyrealnumberiseitherrationalorirrational. p) Ifanumberisrealthenitisirrational.

q) Thereareaninfinitenumberofrealnumbers r) Arationalnumbertimesanirrationalnumberis between0and1 alwaysirrational.

s) Betweenanytwoirrationalnumbersisanother t) Anirrationalnumbertimesanirrationalnumber irrationalnumber. isalwaysanirrationalnumber.

Lambrick Park Secondary

Section 1.1 - Number Systems ♦ 7

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

2. Considerthelistofnumbers: 12, 2.7, 0, , , , 4.21, 501332 r- - .Listall:

a) Naturalnumbers b) Wholenumbers

c) Integers d) Rationalnumbers

e) Irrationalnumbers f) Realnumbers

3. Considerthelistofnumbers: 4, 0. , 0, 0.121121112 , 2.3535 , 2 , 12,3 1031f f- .Listall:

a) Naturalnumbers b) Wholenumbers

c) Integers d) Rationalnumbers

e) Irrationalnumbers f) Realnumbers

4. Considerthelistofnumbers: , , , . , . , , . ,64 64 0 008 0 04 0 494

7218

903 3- - .Listall:

a) Naturalnumbers b) Wholenumbers

c) Integers d) Rationalnumbers

e) Irrationalnumbers f) Realnumbers

Lambrick Park Secondary

8 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

5. Statethenumbersystemseachofthefollowingbelongto.(Natural,Whole,Integer,Rational,Irrational,Real)

a) 16 b) r

c) 0 d) .2 34

e) 4.010010001f f) −3.181818f

g) 1227 h) .0 0004

6. Listeachofthefollowing:

a) Naturalnumberslessthan4 b) Naturalnumbersgreaterthan5

c) Wholenumberslessthan2 d) Integersgreaterthan−3

e) Positiveintegersgreaterthan−4 f) Wholenumberslessthan0

g) Non-negativeintegerslessthan4 h) Non-positiveintegersgreaterthan−4

i) Negativeintegersgreaterthan−3 j) Positiveandnegativeintegersbetween−2and2

k) Naturalnumberslessthan1 l) Wholenumberslessthan1

m) Negativeintegersgreaterthan−3.205 n) Positivewholenumberslessthan2.758

o) Naturalnumbersbetween−3and2 p) Wholenumbersbetween−3and2

Lambrick Park Secondary

Section 1.2 - Greatest Common Factor and Least Common Multiple ♦ 9

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

AkeyconceptinfindingtheGCFandLCMisfactoring.Factoringisthedecompositionofanumberinto aproductofothernumbers,orfactors,whichwhenmultipliedtogethergivetheoriginalvalue.

Forexample: 4isafactorof12because4 3 12# = 4isnotafactorof18becausethereisnowholenumberksuchthat k4 18# =

Next,considertwoveryspecialtypesofwholenumberscalledprimenumbersandcompositenumbers.

Prime Numbers and Composite Numbers

Aprimenumberisawholenumberthathasexactlytwofactors:1anditself.

Acompositenumberisawholenumbergreaterthan1thathasadivisorotherthanonoritself,or inotherwords,isnotprime.Everycompositenumberhasmorethantwofactors.

List of Prime Numbers Less Than 100

2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97

Note: Thesetofprimenumbersisinfinite.AsofAugust23,2008thelargestprimenumberthathasbeen discoveredis2 143112609

- .Thisnumberhas12978189digits!(Printingthisnumberwouldtake about2200pages.)

Zero and One

Thewholenumbers0and1areneitherprimenorcomposite.

Zeroisnotaprimenumberbecauseithasaninfinitenumberofdivisors.Oneisnotaprimenumber becauseitdoesnothavetwodifferentpositivewholenumberdivisors.

Whichofthefollowingarecompositenumbers:3,10,18,23,29

►Solution: 10 2 5#= and18 2 3 3# #= ,therefore10and18arecomposite.Theothersareprime.

Example 1

Greatest Common Factor and Least Common Multiple1.2

Lambrick Park Secondary

10 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Divisibility Properties

Divisibilityby2: Awholenumberisdivisibleby2ifitslastdigitis0,2,4,6or8. Divisibilityby3: Awholenumberisdivisibleby3ifthesumofitsdigitsaredivisibleby3. Divisibilityby4: Awholenumberisdivisibleby4ifthelasttwodigitsaredivisibleby4. Divisibilityby5: Awholenumberisdivisibleby5ifthelastdigitis0or5. Divisibilityby6: Awholenumberisdivisibleby6ifitisanevennumberthatisdivisibleby3. Divisibilityby9: Awholenumberisdivisibleby9ifthesumofitsdigitsaredivisibleby9. Divisibilityby10: Awholenumberisdivisibleby10ifitendsina0.

Determinewhichofthe4digitnumbersaredivisiblebythegiven1or2digitnumber.

a)4735,2638;2b)2783,5271;3c)4384,6394;4d)3753,8240;5

e)7936,2898;6f)3564,5239;9g)9625,3780;10

►Solution: a) 2638endsinanevennumber,therefore2638isdivisibleby2.

4735endsinanoddnumber,therefore4735isnotdivisibleby2.

b) Thedigitsof5271addto15 5 2 7 1 15+ + + =^ h,whichisdivisibleby3,therefore 5721isdivisibleby3.

Thedigitsof2783addto20 2 7 8 3 20+ + + =^ h,whichisnotdivisibleby3,therefore 2783isnotdivisibleby3

c) Thelasttwodigitsof4384are84,whichisdivisibleby4,therefore4384isdivisibleby4.

Thelasttwodigitsof6394are94,whichisnotdivisibleby4,therefore6394isnot divisibleby4.

d) Thelastdigitof8240is0,therefore8240isdivisibleby5.

Thelastdigitof3753is3,therefore3753isnotdivisibleby5.

e) Thedigitsof2898addto27 2 8 9 8 27+ + + =^ h,whichisdivisibleby3,and2898isan evennumber,therefore2898isdivisibleby6.

Thedigitsof7936addto25 7 9 3 6 25+ + + =^ h,whichisnotdivisibleby3,therefore 7936isnotdivisibleby6.

f) Thedigitsof3564addto18 3 5 6 4 18+ + + =^ h,therefore3564isdivisibleby9.

Thedigitsof5239addto19 5 2 3 9 19+ + + =^ h,therefore5239isnotdivisibleby9.

g) Thelastdigitof3780is0,thereforeitisdivisibleby10.

Thelastdigitof9625is5,thereforeitisnotdivisibleby10.

Example 2

Lambrick Park Secondary

Section 1.2 - Greatest Common Factor and Least Common Multiple ♦ 11

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Finding Prime Factors of Composite Numbers

Threemethodsforfindingtheprimefactorsofthenumber72willbeshown.

Method1:FactorTree

or or

Therefore72factorsinto2 2 2 3 3# # # # .

Method2:DividingByPrimesUntilTheQuotientIsAPrimeNumber

Startwiththeprimenumber2andrepeatedlydivideintoeachresultingdividenduntilitisnolongerpossible.

2 7236g ,2 36

18g ,2 189g

Onceitisnolongerpossibletodividewith2trythenextprimenumber3.

3 93g

Thedivisorsareprimenumbersandthequotientisprime,therefore72factorsinto2 2 2 3 3# # # # .

Method3:ContinuousDivision

2 72 ←2dividesinto72.Since36isnotprime,continue. 2 36 ←2dividesinto36.Since18isnotprime,continue. 2 18 ←2dividesinto18.Since9isnotprime,continue. 3 9 ←3dividesinto9.Sincethequotientisprime,stop. 3

Therefore72factorsinto2 2 2 3 3# # # # .

72

2

4

2 3

9

32

36

72

4

2

3

2

18

2 9

3

72

8

34

2

3

2

2

9

Lambrick Park Secondary

12 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Theprimefactorsoftwoormorecompositenumberscanbeusedtofindtheirgreatestcommonfactor.

Forexample: 60 2 2 3 5# # #= 72 2 2 3 3# # #=

Sincetwo2’sanda3arecommontoboth,thegreatestcommonfactorof60and72is2 2 3 12# # = .

Greatest Common Factor (GCF)

Thelargestnumberthatdivideseachofthegivennumbersexactly.

Finding the Greatest Common Factor

1. Findtheprimefactorsofeachnumber. 2. Listeachcommonfactortheleastnumberoftimesitappearsinanyonenumber. 3. Findtheproductofthefactors.

FindtheGCFof36,48,60.

►Solution: 36 2 2 3 3# # #= 2 32 2#=

48 2 2 2 2 3# # # #= 2 34#=

60 2 2 3 5# # #= 2 3 52# #=

Thecommonfactorsare2and3.

Theleastnumberof2’sis2² Theleastnumberof3’sis3.

ThereforetheGCFof36,48,60is2 3 122# = .

FindtheGCFof32,40,60.

►Solution: 3 2 22 2 2 2# # # #= 25=

4 2 2 20 5# # #= 2 53#=

60 2 2 3 5# # #= 2 3 52# #=

Theonlycommonfactoris2.Theleastnumberof2’sis2².

ThereforetheGCFof32,40,60is2²=4.

Example 3

Example 4

Lambrick Park Secondary

Section 1.2 - Greatest Common Factor and Least Common Multiple ♦ 13

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Theprimefactorsoftwoormorecompositenumberscanbeusedtofindtheirleastcommonmultiple.

Forexample: 60 2 2 3 5# # #= 72 2 2 3 3# # #=

Theonlyuniqueprimefactoris5.Thehighestpowerof2is2².Thehighestpowerof3is3².

Theleastcommonmultipleof60and72is5 2 3 1802 2# # = .

Multiple

Theproductofanumberbywholenumber

Forexample,themultiplesof7are:0,7,14,21,28...

Least Common Multiple (LCM)

Thesmallestcommonnon-zeromultipleoftwoormorewholenumbers,orthesmallest numberthatisdivisiblebyallthenumbers.

Finding the Least Common Multiple (Method 1)

1. Determineifthelargestnumberisamultipleofthesmallernumber.Ifso,thelargernumberistheLCM. 2. Ifnot,writemultiplesofthelargernumberuntilyoufindonethatisamultipleofthesmallernumbers.

FindtheLCMof15and18.

►Solution: 15isnotamultipleof18

2 18 36# = isnotamultipleof15

3 18 54# = isnotamultipleof15

4 18 72# = isnotamultipleof15

5 18 90# = isamultipleof15,6 15 90# =

ThereforetheLCMof15and18is90.

Example 5

Lambrick Park Secondary

14 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Finding the Least Common Multiple (Method 2)

1. Writeeachnumberasaproductofitsprimefactors. 2. Selecttheprimesthatoccurthegreatestnumberoftimesinanyonefactor. 3. TheLCMistheproductoftheseprimes.

FindtheLCMof60and72.

►Solution: 60 2 2 3 5# # #= 2 3 52# #= 72 2 2 2 3 3# # # #= 2 33 2#=

Theuniqueprimefactorsare2,3and5

Thehighestpowerof2is23. Thehighestpowerof3is32. Thehighestpowerof5is5.

ThereforetheLCMof60and72is2 3 5 3603 2# # = .

FindtheLCMof35,60and75.

►Solution: 35 5 7#= 60 2 2 3 5# # #= 2 3 52# #= 7 35 5 5# #= 3 52#=

Theuniqueprimefactorsare2,3,5and7

Thehighestpowerof2is22. Thehighestpowerof3is3. Thehighestpowerof5is52. Thehighestpowerof7is7.

ThereforetheLCMof35,60and75is2 3 5 72 2# # # =2100.

Example 6

Example 7

Lambrick Park Secondary

Section 1.2 - Greatest Common Factor and Least Common Multiple ♦ 15

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Finding the Least Common Multiple (Method 3) (Forusewith3ormorenumbers)

1. Dividebyaprimefactorthatcandividetwoormoreofyournumbers.Bringdownanynumberthatdoes notfactor. 2. Repeat,untilnoremainingnumbershaveanyprimefactorsincommon.

FindtheLCMof15,18and24.

►Solution: , ,3 15 18 24 allthreenumbersaredivisibleby3 2 , ,5 6 8 6and8aredivisibleby2,bringdownthe5 5,3,4 noremainingcommonprimefactors

ThereforetheLCMof15,18and24is3 2 5 3 4 360# # # # =

FindtheLCMof27,30and36.

►Solution: , ,2 27 30 36 30and36aredivisibleby2,bringdownthe27 , ,3 27 15 18 allthreenumbersaredivisibleby3 , ,3 9 5 6 6and9aredivisibleby3,bringdownthe5 3,5,2 noremainingcommonprimefactors

ThereforetheLCMof27,30and36is2 3 3 3 5 2 540# # # # # =

Simplify728140 usingprimes.

►Solution: 140 2 2 5 7# # #=

728 2 2 2 7 13# # # #=

Therefore728140

2 2 2 7 13

2 2 5 7

265

# # # #

# # #= =

Example 8

Example 9

Example 10

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16 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

1.2 Exercise Set

1. Withouttheuseofacalculator,determinewhichofthefollowingnumbers:63,126,280,396,575,2610,7800 aredivisibleby:

a) 2 b) 3

c) 4 d) 5

e) 6 f) 9

g) 10

2. Thenumber530hasamissinglastdigit.Determinethesmallestdigitsothatthe4digitnumberis divisibleby:

a) 2 b) 3

c) 4 d) 5

e) 6 f) 9

g) 10

Lambrick Park Secondary

Section 1.2 - Greatest Common Factor and Least Common Multiple ♦ 17

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

3. Thenumber3689hasamissinglastdigit.Determinethesmallestdigitsothatthe5digitnumberis divisibleby

a) 2 b) 3

c) 4 d) 5

e) 6 f) 9

g) 10

4. Bytestingnumbers,determinewhichofthefollowingstatementsaretrue.

a) Anumberisdivisibleby8ifthelastthreedigitsaredivisibleby8. T/F

b) Anumberisdivisibleby11if,startingfromthefirstdigit,youfindthesumof T/F everyalternatedigit,andthensubtractthesumoftheremainingdigitstoget anewvaluewhichisdivisibleby11.

c) Anumberisdivisibleby12ifitisdivisiblebyboth3and4. T/F

d) Anumberisdivisibleby15ifitisdivisiblebyboth3and5. T/F

e) Anumberisdivisibleby18ifitisdivisiblebyboth2and9. T/F

Lambrick Park Secondary

18 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

5. Listthefirsteightmultiples.

a) 3 b) 6

c) 8 d) 12

6. Decidewhetherthenumberisprimeorcomposite.Ifthenumberiscomposite,factoritintoprimes.

a) 19 b) 51

c) 87 d) 101

e) 117 f) 199

g) 611 h) 997

i) 629 j) 551

7. Simplifyusingprimefactorization.

a)455385 b)

11881155

c)23101848 d)

57754950

e)35752600 f)

26182210

Lambrick Park Secondary

Section 1.2 - Greatest Common Factor and Least Common Multiple ♦ 19

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

8. Completelyfactoreachofthenumbers.

a) 36 b) 78

c) 84 d) 169

e) 178 f) 425

g) 1000 h) 6250

i) 2431 j) 5681

9. Findthegreatestcommonfactor.

a) 12,28 b) 54,66

c) 48,136 d) 65,169

e) 81,108 f) 30,45,60

g) 12,27,42 h) 28,42,84

i) 52,130,182 j) 66,165,231

Lambrick Park Secondary

20 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

10. Findtheleastcommonmultiple.

a) 5,10 b) 12,16

c) 21,48 d) 24,56

e) 30,55 f) 6,12,15

g) 12,16,24 h) 20,36,48

i) 7,11,13 j) 28,35,42

k) 22,33,66 l) 4,36,225

m) 8,27,125 n) 14,84,98

o) 2,8,12,18 p) 9,15,25,45

11. Fillinthemissingnumbers.

Product 6 48 18 72 108 32 75

Factor 2 7 7 11

Factor 3 9 6 9

Sum 5 16 11 22 31 12 13 12 20

Lambrick Park Secondary

Section 1.2 - Greatest Common Factor and Least Common Multiple ♦ 21

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

12. Mercury,VenusandEarthrevolvearoundtheSun 13. Earth,Jupiter,Saturn,andUranusrevolvearound every3,7and12monthsrespectively.Ifthethree theSunevery1,12,30,and84yearsrespectively. planetsarecurrentlylinedup,howmanymonths Ifthefourplanetscurrentlylineup,howmany willpassbeforethishappensagain? yearswillpassbeforetheywouldlineupagain?

14. Tom,DickandHarrygethalfdaysoffwithpay. 15. Thereare6playersonavolleyballteam,9players Tomgetsahalfdayoffwithpayeveryeightdays, onabaseballteam,and11playersonasoccerteam. Dickevery10daysandHarryevery12days.If Whatisthesmallestnumberofstudentsinaschool allthreeareofftogetheronApril1,whatisthe thatcanbesplitevenlyintoanyofthethreeteams? nextdatewhenallthreewillbeofftogetheragain?

16. ThereisauniquewayoffindingtheLCMoftwo 17. FindtheLCMof72,108bytakingtheproductof numbers.Taketheproductofbothnumbers,and bothnumbersanddividingthatproductbytheGCF. dividethatproductbytheGCF.FindtheLCM of18,24bythismethod.

18. TheFieldsMedal,thehighestscientificawardfor 19. Whatisthesmallestwholenumberdivisibleby Mathematics,isawardedevery4years.Itwas everywholenumberfrom1to10? awardedin2010.TheBirkhoffPrizeforApplied Mathematicsisawardedevery3years.Itwas awardedin2009.Whatarethefirsttwotimes bothawardsweregiveninthesameyearinthe 21stcentury?

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22 ♦ Chapter 1 - Real Numbers

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Tosquareanumbermeanstoraisethenumbertothesecondpower.

Forexample: 4 4 4 162 #= =

9 9 9 812 #= =

Somenumberscanbewrittenastheproductoftwoidenticalfactors.

Forexample: 25 5 5#=

64 8 8#=

Theseidenticalfactorsarecalledthesquare rootofthenumber.Thesymbol (calledaradicalsign)isused toindicatesquareroots. 25 5= and 64 8= .

Allnumberswithsquarerootsthatarerationalarecalledperfect squares.

A List of Perfect Square Whole Numbers

0,1,4,9,16,25,36,49,64,81,100,121,144,169,196,225,256,289,324,361,400,441,484,529,576,625

Determinewhichareperfectsquares.

a)4b)94 c)7 d)

154

►Solution: a) Yes,because7 7 49# = .

b) Yes,because323294

# = .

c) No,because7cannotbewrittenastheproductoftwoidenticalrationalnumbers.

d) No,because154 cannotbewrittenastheratiooftwoidenticalrationalnumbers.

Example 1

Squares and Square Roots1.3

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Section 1.3 - Squares and Square Roots ♦ 23

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Finding Square Roots Without a Calculator or Table

Method1:FactorTree

Example:Determiningthesquarerootof196.

or

Therefore 196 2 2 7 7 2 2 7 7 2 7 14# # # # # # #= = = =

Note: Forwholenumbers x x x x2 #= =

Method2:ContinuousDivision

Example:Determiningthesquarerootof441

441isnotdivisibleby2,butisdivisibleby3so:

3 441 ←3dividesinto441.Since147isnotprime,continue. 3 147 ←3dividesinto147.Since49isnotprime,continue. 7 49 ←7dividesinto49.Since7isprime,stop. 7

Therefore 441 3 3 7 7 3 3 7 7 3 7 21# # # # # # #= = = =

196

2

7

98

2 49

7

7

49

7

196

4

2 2

Lambrick Park Secondary

24 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Cubes and Cube Roots

Tocubeanumbermeanstoraisethenumbertothethirdpower,ortomultiplythenumberbyitselfthreetimes.

Forexample: 4 4 4 4 643 # #= =

7 7 7 7 3433 # #= =

Somenumberscanbewrittenastheproductofthreeidenticalfactors.

Forexample: 27 3 3 3# #=

125 5 5 5# #=

Theseidenticalfactorsarecalledthecube rootofthenumber.Thesymbol3 (calledaradicalsign)isused toindicatecuberoots. 27 33

= ,and 125 53=

A List of Perfect Cube Whole Numbers

0,1,8,27,64,125,216,343,512,729,1000

Determinewhichareperfectcubes.

a) 8b)6427 c)25 d)

98

►Solution: a) Yes,because2 2 2 8# # = .

b) Yes,because4343436427

# # = .

c) No,because25cannotbewrittenastheproductofthreeidenticalintegers.

d) No,becauseitcannotbewrittenastheproductofthreeidenticalrationalnumbers.

Note: Intheexpression ak ,wecallktheindex,andassumek 2$ .Iftheindexisnotwritten,theexpression isassumed tobeasquareroot,i.e.k=2.

eg. 32 25 = because2 2 2 2 2 32# # # # =

Example 2

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Section 1.3 - Squares and Square Roots ♦ 25

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Finding Cube Roots Without a Calculator or Table

Method1:FactorTree

Example:Findthecuberootof216.

or

Therefore 216 2 2 2 3 3 3 2 2 2 3 3 3 2 3 63 3 3 3# # # # # # # # # # #= = = =

Note: Forwholenumbers, x x x x x33 3 # #= =

Method2:ContinuousDivision

Example:Findthecuberootof729.

729isnotdivisibleby2,butisdivisibleby3so:

3 729 ←3dividesinto729.Since243isnotprime,continue. 3 243 ←3dividesinto243.Since81isnotprime,continue. 3 81 ←3dividesinto81.Since27isacuberootnumber,stop. 27

Therefore 729 3 3 3 27 3 3 3 27 3 3 93 3 3 3# # # # # # #= = = =

216

2

2

2

108

54

27

3

3

9

3

216

2

2

27

3

3

8

4

2

9

3

Lambrick Park Secondary

26 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

1.3 Exercise Set

1. Findthesquarerootoftheperfectsquareswithoutacalculator.

a) 100 b) 441

c) 225 d) 361

e) 529 f) 2890000

g) 25000000 h) 72 900-

i) 9 610000- j) .0 000004

2. Findthecuberootoftheperfectcubeswithoutacalculator.

a) 273 b) 10003

c) 3433 d) 17283

e) 33753 f) 80003

g) 1250000003 h) 2160003-

i) 640000000003- j) .0 0000083

Lambrick Park Secondary

Section 1.3 - Squares and Square Roots ♦ 27

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

3. Findtheperfectsquareroot,ifitexists,withoutacalculator.

a) 25 b) 29

c) 80 d) 81

e) 169 f) 99

g) 1600 h) 900

i)40081 j)

188

4. Findtheperfectcuberoot,ifitexists,withoutacalculator.

a) 8 b) 9

c) 64 d) 81

e) 100 f) 216

g) 1000 h) 144

i) 625 j) 729

Lambrick Park Secondary

28 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

5. Theareaofabaseballdiamondis8100ft². 6. PoliceusetheformulaS x2 5= todeterminethe speed,Sinmilesperhourofaskidoflengthxft. a) Howfarisitfromhomeplatetofirstbase? Determinethespeedofacarwhoseskidlengthis

a) 45ft.

b) Howfarisitfrom1stbaseto3rdbase? b) 180ft.

7. Theareaofarectanglewithlengthtwiceaslong 8. Acubehasavolumeof216cm³.Determinethe asthewidthis1250m².Determinethelength lengthofeachsideofthecube. andwidthoftherectangle.

9. Arectangularsolidhasalengththreetimesthe 10. Thevolumeofasphereisgivenbytheformula widthandaheighttwiceitswidth.Ifthevolume V r34

3r= ,withrtheradiusofthesphere. oftherectangularsolidis384in³,determinethe Determinetheradiusofaspherewithvolume dimensionsoftherectangularsolid. 972r mm³.

Lambrick Park Secondary

Section 1.4 - Rational and Irrational Numbers ♦ 29

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Ifarealnumberisnotrational,itmustbeirrational.Allnumberswithsquarerootsthatarerationalmustbe perfectsquares.Thisisalsotrueforcuberoots.

Forexample: 25 Thisisarationalnumbersince25isaperfectsquare; 25 5=

253 Thisisanirrationalnumbersince25isnotaperfectcube.

Remember,arationalnumberisanumberthatcanberepresentedasafraction.Anirrationalnumberisa non-repeating,ornon-terminatingdecimalvalue.Therefore,whenwritingavalueforanirrationalnumber,it isjustanapproximation.

Irrationalnumbersdonothavetobethen throotofaninteger.Herearesomeotherexamplesofirrational numbers:

r ,e,1.010010001..., 2

Approximating Irrational Numbers

Withtheuseofacalculator,anapproximationofthefollowingvalueswereobtained.

.7 2 650 .70 8 370 .700 26 50 .7000 83 70

Noticethat 7 and 700 havethesamenumerals,butdifferentdecimalpointanswers.Thisisbecause 700 7 100 7 10# #= = .Thesameisalsotruefor 70 and 7000 70 100#= .

Withouttheuseofacalculator,anapproximationofann throotcanbefoundbydeterminingwherethevalue liesonanumberline.

Betweenwhattwoconsecutiveintegersis 7 ?

►Solution: Letaandbbeconsecutiveintegerssothata b71 1 .

Thereforea b72 21 1 .

Since2 42= and3 92

= :2 7 3 2 7 32 2"1 1 1 1

So 7 liesbetween2and3.

Example 1

Rational and Irrational Numbers1.4

Lambrick Park Secondary

30 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Betweenwhattwoconsecutiveintegersis 1003 ?

►Solution: Letaandbbeconsecutiveintegerssothata b10031 1 .

Thereforea b1003 31 1 .

Since4 643= and5 1253

= :4 100 5 4 100 53 3 3"1 1 1 1

So 1003 liesbetween4and5.

Further Approximation of Irrational Numbers

Thepreviousexamplesshowroughapproximationsofirrationalnumbers.Addingsomeadditionalstepsto theprocesswillallowourestimatestobeclosertotheactualvalue.

Approximate 11 toonedecimalplace.

►Solution: Letaandbbeconsecutiveintegerssothata b111 1 .Thereforea b112 21 1 .

Since3 92= and4 162

= :3 11 4 3 11 42 2"1 1 1 1

Then9 11 161 1 showsus11is2unitsfrom9,and5unitsfrom16.

Byratios: .2 52 0 30+

units

Therefore .11 3 30 (Check: . .3 3 10 892 - )

Approximate 1403 toonedecimalplace.

►Solution: Letaandbbeconsecutiveintegerssothata b14031 1 .Thereforea b1403 31 1 .

Since5 1253= and6 2163

= :5 140 6 5 140 63 3 3"1 1 1 1

Then125 140 2161 1 showsus140is15unitsfrom125and76unitsfrom216.

Byratios: .15 7615 0 20+

units

Therefore .140 5 23 0 (Check: . .5 2 140 63 - )

Example 2

Example 3

Example 4

Lambrick Park Secondary

Section 1.4 - Rational and Irrational Numbers ♦ 31

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

1.4 Exercise Set

1. Withoutacalculator,decideifthenumbersarerationalorirrational.

a) 81 b) 810

c) 40 d) 400

e) .6 4 f) .0 64

g) .0 004 h) .0 0004

i) 22500 j) .22 5

k) 322 l) .0 322

2. Withoutacalculator,decideifthenumbersarerationalorirrational.

a) 13 b) 103

c) 1003 d) 10003

e) 83 f) 803

g) 8003 h) 80003

i) .0 83 j) .0 083

k) .0 0083 l) .0 00083

Lambrick Park Secondary

32 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

3. Usingacalculator,approximatetheirrationalnumbersto2decimalplaces.

a) .2 3 b) 23

c) 230 d) .0 23

e) 2300 f) .0 023

g) .7 93 h) 793

i) 7903 j) 79003

k) .0 793 l) .0 00793

4. Given .21 4 580 and .210 14 490 ,determinethevalueofthesquareroot.

a) .2 1 b) .0 21

c) 2100 d) .0 021

e) 21000 f) .0 0021

g) 210 000 h) .0 00021

i) 2100 000 j) .0 000021

Lambrick Park Secondary

Section 1.4 - Rational and Irrational Numbers ♦ 33

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

5. Given .21 2 763 0 , .210 5 943 0 and .2100 12 813 0 ,determinethevalueofthecuberoot.

a) 210003 b) .2 13

c) 2100003 d) .0 213

e) .0 0213 f) .0 00213

g) 2100 0003 h) .0 000213

i) 21000 0003 j) .0 0000213

6. Estimatethepositionofeachirrationalnumberonthenumberlineprovided.

a) 11

b) 32-

c) 29

d) .1 9-

e) 1003

f) 873-

g) 1533

0 4 5 6321

0 4 5 6321

0 4 5 6321

0 4 5 6321

0 4 5 6321

0 4 5 6321

0 4 5 6321

Lambrick Park Secondary

34 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

7. Withoutusingtherootfunctionsofacalculator,approximatetheirrationalnumbertoonedecimalpoint.

a) 30 b) 58-

c) 88 d) 76-

e) 130 f) 983

g) 743- h) 43

i) 113- j) 193

8. Ordertheirrationalnumbersonthenumberlineprovided.

a) , , , ,18 27 30 22r - -

b) , , , ,e73 130 30 1103 3 3 3-

c) , , , , ,10 10 17 17 28 283 3 3- -

0 4 5 6321

0 4 5 6321

0 4 5 6321

Lambrick Park Secondary

Section 1.5 - Exponential Notation ♦ 35

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Anexponenttellshowmanytimesthebaseisusedasafactor.Inthestatementa a a a a a5# # # # = ,the exponentis5andthebaseisa.Thisisread“atothefifthpower”.

Forexample: 24 means 2 2 2 2# # #

a3 2^ h means a a3 3#

y 3-^ h means y y y# #- - -^ ^ ^h h h

10p3 means p p p10 # # #

One and Zero as Exponents

Considerthefollowingexample:

3 3 3 3 34# # # = 3 3 3 33# # = 3 3 32# =

Ontheleftsideoftheequationeachstepisbeingdividedby3.Ontherightsideoftheequation,theexponent decreasesby1oneachstep.

Tocontinuethepattern:

3 31= 1 30=

Exponents of 0 and 1

a a1= ,foranynumbera.

a 10= ,foranynon-zeronumbera.

Note:00isnotdefined.

Examples: 5 10=

17 171=

32 10

=` j

5 10- =-

5 10- =^ h

Exponential Notation1.5

Lambrick Park Secondary

36 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

The Product Rule

Considerthefollowingexample:a a a a aa a a2 3 5# # # # #= =^ ^h h

Theexponentintheexpressiona5isthesumoftheexponentsintheexpressiona a2 3# . Therefore:a a a a2 3 2 3 5# = =+ .

Product Rule

Foranynumbersaandbwithexponentsmandn:

,a a a a 0m n m n# != +

Examples: 3 3 3 34 5 4 5 9#- - = - = -+^ ^ ^ ^h h h h

32

32

32

325 1 5 6

# = =+` ` ` `j j j j

22 8 2 2 2 2 23x x x x x x x xx3 2 3 3 6 3 6 92# # #= = = =+^ h

The Quotient Rule

Considerthefollowingexample:aa

a a a

a a a a a a aa a a a a3

74

# #

# # # # # ## # #= = =

Theexponentintheexpressiona4isthedifferenceoftheexponentsintheexpressionaa3

7

. Therefore:

aa a a3

77 3 4

= =- .

Quotient Rule

Foranynumberawithexponentsmandn:

,aa a a 0n

mm n != -

Examples:4

44 43

8

8 3 5

-

-= - = --

^^ ^ ^hh h h

5353

53

53

6

6 1 5

= =-

`

`` `

j

jj j

Lambrick Park Secondary

Section 1.5 - Exponential Notation ♦ 37

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

The Power Rule

Anexpressionsuchas 52 3^ h means5 5 52 2 2# # .Bytheproductrule5 5 5 5 52 2 2 2 2 2 6# # = =+ + .Butwecan alsogetto56bymultiplyingtheexponents: 5 5 52 3 2 3 6

= =#^ h .

Power Rule

Foranynumbersaandbwithexponentsmandn:

a am n m n= #^ h

Examples: 3 3 35 4 5 4 20= =#^ h

2 2 23 3 3 3 9- = - = -#^ ^ ^h h h6 @

52

52

523 4 3 4 12

= =#

` ` `j j j8 B

Raising a Product to a Power

Anexpressionsuchas x2 3^ h means x x x2 2 2# # . Thisexpressioncanbewritten: x x x x x2 2 2 2 83 3 3# # # # # #= =^ ^h h .

A Product to a Power

Foranynumbersaandbwithexponentn:

ab a bn n n#=^ h

Examples: x x x3 3 273 3 3 3#= =^ h

y y y2 2 162 4 4 2 4 8#= =#^ h

a b a b a b3 3 93 4 2 2 3 2 4 2 6 8# #- = - =# #^ ^h h

Lambrick Park Secondary

38 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Raising a Fraction to a Power

Anexpressionsuchas32 4` j means

32323232

# # # .Multiplyingthefractionsgives:3 3 3 32 2 2 2

32

8116

4

4

# # ## # # = = .

A Fraction to a Power

Foranynumbersaandb, b 0! ,withexponentn:

ba

ban

n

n

=` j

Examples:x x x2 2 83

3

3

3= =` j

a a a1 1 14

2

4 2

2

8= =#c m

Negative Exponents

Considerthefollowingexample:55

5 5 5 5 5 5

5 55 5 5 5

151

6

2

4# # # # #

## # #

= = = .

Solvingthepreviousexamplewiththequotientrulegives:55 5 56

22 6 4

= =- -

Therefore51 54

4= -

Negative Exponents

Foranynumbera, 0a ! ,withexponentn:

aa1nn=-

Examples: 221

813

3= =-

xx x

221

1614

4 4= =-^ ^h h

Lambrick Park Secondary

Section 1.5 - Exponential Notation ♦ 39

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Changing from Negative to Positive Exponents

Considertheexpression213- .Bythenegativeexponentrule,thisisequivalentto2 23 3

=- -^ h .

Changing from Negative to Positive Exponents

Foranynon-zeronumbersaandb,withexponentsmandn:

ba

ab

n

m

m

n

=-

-

andba

abm m

=-` `j j

Examples:

32

23

8273 3

= =-` `j j

43

34

964

3

2

2

3

= =-

-

Rational Exponents: a 1n

Considerthesquarerootexample: 2 2 2# = .

Nowconsidertheexponentruleexample:2 2 2 2 221

21

2121

1# = = =+ .

Since 2 2# and2 221

21

# equal2, 2 shouldequal221

.

Rational Exponents: a 1n

Foranynon-negativerealnumberaandanypositiveintegern.

a ann

1

=

Examples: x x21

=

224 41

=

2 2 2 2 2 2 2 8421

41

2141

43

34 4# #= = = = =+

Lambrick Park Secondary

40 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Rational Exponents: a nm

Thisisamoregeneralversionofrationalexponents.

Bythepowerrule,8 2 168 834

31 4 3 4 4

= = = =^ ^h h

However,834

canalsobewrittenas 168 8 4096431

43 3= = =^ h

Rational Exponents: a nm

Foranynon-negativerealnumberaandanypositiveintegern.

a anm mn=

Examples:4 2 2 2 823

223

223

3= = = =#^ ch m

32 32 2 2 165 454

554

4= = = =^ ^h h

162

121

81

43

43

43= = =-

^ h

2

4

2

4

2

2

2

2 2 2 2 324

3

41

31

41

2

41

32

3241

128

123

51231

12= = = = = = =- -^ h

9 27 9 27 3 3 3 3 3 3 3 2 2 2 2 323 431

41

231

341

32

43

3243

128

129

1217

1712 12 512 12$ $ $ $$ = = = = = = = = =+ +^ ^h h

Lambrick Park Secondary

Section 1.5 - Exponential Notation ♦ 41

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Summary of Exponent Rules

Foranyintegersmandn:

Exponentof1 a a1= 3 31

=

Exponentof0 ,a a1 00 != 5 10- =^ h

ProductRule ,a a a a 0m n m n# != + 2 2 2 23 4 3 4 7# = =+

QuotientRule ,aa a a 0n

mm n != -

33 3 33

55 3 2

= =-

PowerRules

a am n m n= #^ h

ab a bn n n#=^ h

ba

ban

n

n

=` j

2 2 23 4 3 4 12= =#^ h

x x2 23 3 3#=^ h

32

324

4

4

=` j

NegativeExponents

aa1nn=-

ba

abn n

=-` `j j

ba

ab

n

m

m

n

=-

-

2213

3=-

43

342 2

=-` `j j

32

23

4

3

3

4

=-

-

RationalExponentsa an

n1

=

a amnnm

=

553 31

=

553443

=

Lambrick Park Secondary

42 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

1.5 Exercise Set

1. Multiply.Leaveanswerinexponentialform.

a) 2 23 4# b) 3 35 7#

c) 4 43 2#- d) 5 50 3#

e) a a a2 3# # f) y y y3 2# #-

g) 8 8 80 1 2# # h)32

323 4

#` `j j

i) 3 3 34 2 1# #- - -^ ^ ^h h h j)21

21

215 3

# #- - --` ` `j j j

2. Divide.Leaveanswerinexponentialform

a)553

6

b)444

8

c)222

8

d)333

9

e)tt2

6

f)xx7

7

g)6

63

4

-

--^

^hh h)

9

96

3

-

--

-

^^hh

i)x

x

2

24

3

-

--^

^hh j)

zz6

2

-

-

Lambrick Park Secondary

Section 1.5 - Exponential Notation ♦ 43

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

3. Simplify.Expresswithoutbracketsornegativeexponents.

a) 24 2^ h b) 53 2-^ h

c) 3 4 2- -^ h d) x3 2 0- -^ h

e) x2 3^ h f) x3 4 2-^ h

g) a2 4 3-^ h h) x y3 4 2 4-^ h

i) a b4 3 2 2- - -^ h j) x y2 3 2 3- - -^ h

4. Simplify.Expresswithoutbracketsornegativeexponents.

a)33 3

5

4 7# b)2 224 3

5

#

c)44 4

1

3#-

-

d)5 55 53 1

4 2

##

-

-

e)7 77 7

2

0 3

##

-

-

f)1111 11

1

2 3#-

g)xx32

3 2

-

^ h h)xx33

2 3-^ h

i) a b c2 2 4 5 3- -^ h j)ba32

4

2 3-

c m

Lambrick Park Secondary

44 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

5. Evaluate.

a) 32 b) 3 2-

c)31 2` j d)

31 2-` j

e) 32- f) 3 2-^ h

g)31 2

- -` j h)31 2

-` j

i)31 2

--` j j)

31 2

- --` j

k) 23 l) 2 3-

m)21 3` j n)

21 3-` j

o) 23- p) 2 3-^ h

q)21 3

- -` j r)21 3

-` j

s)21 3

--` j t)

21 3

- --` j

Lambrick Park Secondary

Section 1.5 - Exponential Notation ♦ 45

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

6. Simplify.Expresswithoutbracketsornegativeexponents.

a)a b

a b ab2 43 4

2 3 2 1 3#-

- -

^^ ^

hh h b)

x yx y x y

1 2

5 2 2 2 2 3#- -

- -^ ^h h

c)m n

m n m n

2

5 23 2 1

1 2 2 2 3 3#-

- - -

^^ ^

hh h d)

a b

a b a b

3

3 32 2 3

2 3 2 1 4 1#- -

- - - -

^^ ^

hh h

e)x y

x y x y

4

3 52 3 2

1 2 1 2 4 2#

- -

- - - -

^^ ^

hh h f)

a b

a b a b

3

3 43 4 2

1 1 2 2 3 4 2#

- -

- - - - - -

^^ ^

hh h

g)x y

x y

x y

x y4 82

2 2 3 3

3 1

1 3 2

-

- -

-

- - -

c cm m h)a bab

a ba b

89

23

2 2

1 2

2 1

2 2 3

-

- -

-

-

c cm m

i)x y

x y x y

12

2 42 2

1 2 2 3 2- - -

^^ ^

hh h j)

x y

x y x y

15

5 62 4

3 4 2 2 5 2

-

- - - -^ ^h h; E

Lambrick Park Secondary

46 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

7. Evaluate.

a) 1643

b) 16 43-

c) 832

d) 8 32-

e) 2734

f) 27 34-

g) 1645

- h) 16 4

5

- -

i) 3254

- j) 32 54

- -

k) 21632

l) 216 32-

m) 12534

- n) 125 34

- -

o) 64 67

p) 64 67

-

q) 49 23

- r) 49 23

- -

s) 128 75

t) 128 75

-

u) 243 56

- v) 243 56

- -

w) 81 45

x) 81 45

-

Lambrick Park Secondary

Section 1.5 - Exponential Notation ♦ 47

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

8. Simplify.Leaveanswerwithpositiveexponents.

a) 2 241

45

# b) 3 332

37

#

c) 4 441

43

# - d) 5 532

31

#- -

e)6

6

45

43

f)7

7

51

52

-

g)8

8 8

73

72

74

#-

-

h)9 9

9

52

54

53

# -

i) a a43

45

# j) b b65

31

# -

k)c

c

65

32

l)d

d

21

31

-

m)49 23

` j n)49 2

3-` j

o)1681 4

3

` j p)1681 4

3-` j

q) a b3 4132^ h r) x y4 2

134^ h

s) a b c32

65

2176

^ h t) x y z34

4325

512

-^ h

Lambrick Park Secondary

48 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

9. Simplifyeachradical.Assumevariablesarepositive.

a) 44 b) 863

c) 1638 d) 2723

e) 9312 f) 428

g) a24 h) b39

i) c46 j) d28

10. Simplify.

a) 2 23# b) 3 34#

c) 2 23 4# d)4

44

3

e)9

273

f)8

164

3

g)4

8x

x x

21 $` j

h)93 27

x

x x$

i)27

81x

x x

31 $` j

j)25

5 125x

x x

3

2$-

Lambrick Park Secondary

Section 1.5 - Exponential Notation ♦ 49

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

11. Identifytheerrors,thencorrecttheresult.

a) 2 2 25 3 8+ = b) 3 3 94 2 6# =

c) 4 4 43 5 15# = d)22 24

123

=

e)22 14

128

= f) x x2 3 5=^ h

g) x x3 3=-- h)

216 82

3

=c m

i) 3 814- = j) x x2 82 4 4

=^ h

k) 2 10- =-^ h l) 0 10=

m) 2 2 11+ =-^ h n)6416

64

16

41= =

Lambrick Park Secondary

50 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Tofactorasquareroot,theproductrulecanbeused.

The Product Rule for Square Roots

Foranyrealnumbers A and B : A B A B# #=

Theproductruleisusedwhenthereisaperfectsquareasafactor.

Consider 72 .Tosimplifythisexpression,therearemanywaystofactor72.

Method1: 72 = 4 18#

= 4 18#

= 2 18#

= 2 9 2# #

= 2 9 2# #

= 2 3 2# #

= 6 2

Analternativewaytoapproachthisproblemistolookforthelargestperfectsquarefactorof72,whichis36.

Method2: 72 = 36 2#

= 36 2#

= 6 2

Simplifyingismucheasierifthelargestperfectsquarefactorisidentifiedinthefirststep.

Simplify 48 .

►Solution: 48 = 16 3#

= 16 3#

= 4 3

Example 1

Irrational Numbers1.6

Lambrick Park Secondary

Section 1.6 - Irrational Numbers ♦ 51

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Squarerootexpressionssuchas 14 or 2 cannotbesimplified,sinceneitherhaveperfectsquarefactors. Sometimes,aftermultiplication,itispossibletosimplifytheproduct.

Forexample: 2 14# = 28

= 4 7#

= 4 7#

=2 7

Tofactoracuberoot,theproductruleisusedagain.

The Product Rule for Cube Roots

Foranyrealnumbers A3 and B3 : A B A B3 3 3# #=

Theproductruleisusedwhenthereisaperfectcubeasafactor.

Simplify 403 .

►Solution: 403 = 8 53 #

= 8 53 3#

= 2 53

Simplifyingproductsofcuberootsfollowsthemethodusedforsimplifyingproductsofsquareroots.

Forexample: 9 63 3# = 543

= 27 23 #

= 27 23 3#

= 3 23

Entire Root

Anexpressionsuchas2 7 iscalledamixed root,andtheexpression 28 iscalledanentire root.Both expressionshavethesamevalue.Anymixedrootcanbechangedtoanentireroot.

Forexample: 9 3 = 9 9 3# # 2 53 = 2 2 2 53 # # #

= 243 = 403

Example 2

Lambrick Park Secondary

52 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

1.6 Exercise Set

1. Findeachproduct.

a) 3 5# b) 7 2#

c) 13 13# d) 5 6#

e) 2 11# f) 2 3 5# #

g) 4 53 3# h) 2 2 23 3 3# #

i) 2 3 53 3 3# # j) 6 7 53 3 3# #

2. Whichoneoftheentirerootscannotbesimplifiedtoamixedroot?

a) , , ,44 46 48 50 b) , , ,18 20 21 24

c) , , ,40 81 100 1253 3 3 3 d) , , ,16 36 54 1283 3 3 3

e) , , ,32 32 100 1003 3 f) , , ,64 64 75 753 3

g) , , ,27 27 50 503 3 h) , , ,8 10 12 20

i) , , ,36 5424 723 3 3 3 j) , , ,12525 25 1253 3

Lambrick Park Secondary

Section 1.6 - Irrational Numbers ♦ 53

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

3. Simplifytoamixedroot.

a) 20 b) 72

c) 45 d) 24

e) 75 f) 125

g) 140 h) 128

i) 80- j) 160-

4. Simplify.

a) 2 9 b) 4 25

c) 6 40 d) 3 8

e) 4 27 f) 6 50

g)25 32- h) 2

31 72-

i) .0 8 125- j) .1 25 128-

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54 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

5. Simplifyeachroot.

a) 403 b) 483

c) 543 d) 1353

e) 1283 f) 1923

g) 2 273 h) 3 163-

i)21 643 j)

53 2503-

6. Multiply,andsimplifyifpossible.

a) 3 6# b) 7 14#

c) 3 27# d) 2 8#

e) 3 24# f) 10 20#

g) 5 6 2 18# h) 4 10 21#-

i) 2 10 3 50# j) 3 12 2 18#- -^ ^h h

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Section 1.6 - Irrational Numbers ♦ 55

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

7. Multiply,andsimplifyifpossible.

a) 4 63 3# b) 9 243 3#

c) 5 53 3# d) 4 543 3#

e) 2 12 303 3# f) 3 25 4 753 3#-

g) 2 10 3 503 3# h) 3 12 2 183 3- -^ ^h h

i) 3 4 2 323 3- -^ ^h h j) 5 49 2 563 3-^ ^h h

8. Withoutacalculator,compareeachexpressionusing>,<or=. (Hint:Converteachexpressiontoanentirerootfirst)

a) 4 1514 b) 162 9 2

c) 3 11 7 2 d) 12 11 13#

e) 54 23 f) 2 7 563 3

g) 2 15 1253 3 h) 5 3 4 43 3

i) 25 67633 3-- j) 7 5523 3--

Lambrick Park Secondary

56 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

9. Expressasanentireroot.

a) 4 3 b) 2 5

c) 7 6 d) 12 2

e) 5 11 f) 4 14

g) 6 3 h) 2 3 3 2#

i) 2 5 3# j) 4 5 3 3#

10. Expressasanentireroot.

a) 3 23 b) 4 33

c) 5 43 d) 3 53

e) 6 63 f) 4 73

g) 7 83 h) 3 2 4 33 3#

i) 2 4 5 53 3# j) 3 6 73 3#

Lambrick Park Secondary

Section 1.6 - Irrational Numbers ♦ 57

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11. Asquarehasanareaof150mm².Whatarethe 12. Acubehasavolumeof192cm³.Whatarethe lengthsofthesidesofthesquare? lengthsofeachedgeofthecube?

13. Thedimensionsofarectangleare9 30 cmby 14. Thedimensionsofarectangleare5 6 cmby 4 105 cm.Calculatetheareaoftherectangle. 34 cm.Calculatetheareaoftherectangle.

15. Thebaseofatriangleis6 14 ftanditsheightis 16. Thebaseofatriangleis5 33 manditsheightis 3 21 ft.Calculatetheareaofthetriangle. 6 55 m.Calculatetheareaofthetriangle.

17. Thedimensionsofarectangularprismare: 18. Thedimensionsofarectangularprismare: length2 10 cm,width3 14 cm,andheight length3 110 m,width2 22 mand 35 cm.Determinethevolumeoftherectangular height4 15 m.Determinethevolumeof prism. therectangularprism.

19. Thedimensionsofarectangularbasepyramidare: 20. Thedimensionsofarectangularbasepyramidare: length2 42 cm,width3 30 cm,andheight length3 26 m,width2 39 m,andheight 4 70 cm.Determinethevolumeofthepyramid. 4 42 m.Determinethevolumeofthepyramid.

Lambrick Park Secondary

58 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

Section 1.1

1. Considerthelistofnumbers: , . , , . , . , , ,2 0 4 0 0 343343334 4 22235 7 2f f- .Listall:

a) Naturalnumbers

b) Wholenumbers

c) Integers

d) Rationalnumbers

e) Irrationalnumbers

f) Realnumbers

Section 1.2

2. Simplifythecompositenumberstoaproductofprimenumbers.

a) 4950 b) 1848

c) 2618 d) 264264

3. Findthegreatestcommonfactor.

a) 126,588 b) 1755,2475

c) 7007,13013 d) 544,600,2250

Chapter Review1.7

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Section 1.7 - Chapter Review ♦ 59

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

4. Findtheleastcommonmultiple.

a) 56,196 b) 90,300

c) 15,20,30 d) 30,45,84

Section 1.3

5. Determinetherootswithoutacalculator.

a) 64 b) 643

c) 729 d) 7293

e) 1296 f) 27443

g) 1764 h) 58323

Section 1.4

6. Withoutacalculator,determineifthenumberisarationalorirrationalnumber.

a) .0 4 b) .0 04

c) 90 d) 900

e) .0 273 f) .0 0273

g) 8003 h) 80003

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60 ♦ Chapter 1 - Real Numbers

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

7. Using . , . , . , . , .18 4 24 180 13 42 18 2 62 180 5 64 1800 12 163 3 30 0 0 0 0 ,determinethevalueofthe radical.

a) .1 8 b) .0 18

c) .0 018 d) 1800

e) 18 000 f) .1 83

g) .0 183 h) .0 0183

i) 18 0003 j) 180 0003

Section 1.5

8. Simplify.Expresswithoutbracketsornegativeexponents.

a)22 2

5

4 3# b)3

3 35

2

2

3 4 2#^

^ ^h

h h

c)x

x22

3 2

4-

-

^^hh d)

yx23

3

2 2-

c m

e) a b c3 2 3 4 2- - -^ h f)ba23

3

2 4- -

c m

g)x y

x y x y

2

2 22 2

2 3

3

2 1 4 1#-

-

-

- -

^^ ^

hh h h)

x y

x y

x y

x y

4

3

2

32 2

1 2

2

2 2 3

-

- -

-

-

c cm m

Lambrick Park Secondary

Section 1.7 - Chapter Review ♦ 61

Copyright © 2009 by Crescent Beach Publishing. No part of this publication may be reproduced without written permission from the publisher.

9. Simplify.Evaluateifpossible.

a) 32 54

b) 32 54

-

c) 625 43

- d) 625 43

- -

e) 27 64 34

#^ h f) 27 64 34

# -^ h

g)8116 4

3

` j h)8116 4

3-

` j

i) x63 j) ,x x 0412 $

k)2

23

l)2

43

m)3

34

3

n)2

43

4

o)2

2 24

3# p)27

3 94

3#

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62 ♦ Chapter 1 - Real Numbers

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Section 1.6

10. Simplifyeachradical.

a) 108 b) 1083

c) 288 d) 2883

e) 3 54 f) 3 543

g) 2 14 28# h) 2 14 283 3#

i) 5 12 54#- j) 5 12 543 3#-

11. Expressasanentireradical.

a) 3 2 b) 3 23

c) 2 5- d) 2 53-

e) 5 2 2 3# f) 5 2 2 33 3#

g) 3 3 2 5 4 2# # h) 4 3 3 4 2 23 3 3# #

Lambrick Park Secondary