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UNIT11 RadicatEm
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u N tr 11 Radical Expressions
List of Objectives
To simplify numerical radical expressions
To simplify variable radical expressions
To add and subtract radical expressions
To multiply radical expressions
To divide radical expressions
To solve an equation containing one or more radical expressions
To solve application problems
UNtT 11 Radical Expressions 38s
SECTION 1 Introduction to Radical Expressions
1.1 Objective To simplify numerical radical expressions
A square root of a positive number x is a number whose square is x.
A square root of 16 is 4 since 42 - -16.
A square root of 16 is -4 since (-4)2: 16.
Every positive number has two square roots, one a positive and one a negative num-ber. The symbol " {", called a radical, is used to indicate the positive or principalsquare root of a number. For example /16 - 4 and \,Ed = 5. The number underthe radical sign is called the radicand.
When the negative square root of a number is to be found, a negative sign is placed infront of the radical. For example -vrl6 - -4 and - vEi = - 5.
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The square of an integer is a perfect square.
An integer which is a perfect square canbe written as the product of prime factors,each of which has an even exponentwhen expressed in exponential form.
To find the square root of a perfect square written in exponential form, remove the
radical sign and multiply the exponent by +
Simplify v6%Write the prime factorization of theradicand in exponential form.
Remove the radical sign and multiply
the exoonent bv 1., '2
Simplify.
/z iit -+J
02-olv -
ul
122 - 144
49:7'7:72B1 =3'3'3'3-34
144 = 2'2'2'2.3.3 : 2a32
ytr%: rB
=52
-)q
lf a number is not a perfect square, its square root t//=1.4142135...can only be approximated, for example, vtr and t/7. t/7 = Z.G4S7S1T . . .
These numbers are irrational numbers. Therr decimal representations never termi-nate or repeat.
The approximate square roots of the positive integers up to 200 can be found inthe Appendix on page 438. The square roots have been rounded to the nearestthousandth.
A radical expression is in simplest form when the radicand contains no factor whichis a perfect sguare. The Product Property of Square Roots is used to simplify radicalexpressions.
The Product Property of Square Roots
lf a and b are positive real numbers, then v66 = \,tr. \tE
386
Example 1
Simplify 3\6-0.
Solution
3 /00' = 31p:F ,E = 31/!Q. 5) -3\/g\tr:E = 3.3V10-= e/10-
Example 3
Find the decimal approximation of t/252. Use thetable on page 438.
Solution
\tr$ = tP:F:7 = t/F-4rt = 2.3rt =6rt=6(2.646)=15,876
UNIT 11 Radical Expressions
Simplify 1166.
Write the prime factorization of the radicand in expo-nential form.
Write the radicand as a product of a perfect square andfactors which do not contain a perfect square.
Use the Product Property of Square Roots.
Simplify.
Simplify /-a.The square root of a negative number is not a real numbersince the square of a real number is always positive.
Simplify \,tr% Then find the decimal approximation.thousandth.
Write the prrme factorization of the radicand in exponentialform.
Write the radicand as a product of a perfect square andfactors which do not contain a perfect square.
Use the Product Property of Square Roots.
Simplify.
Replace the radical expression by the decimal approxima-tion found on page 438.
= v/F'5
Simplify. = 11.180
Note that in the table on page 438, the decimal approximation of /i25 is 11.180.
Example 2
Simplify -5\/32.
Your solution
Example 4
Find the decimal approximation oltable on page 438.
Your solution
v/06: \F;Z
= 1/Ve.3)
= \/FlE*- 221/24
,t;- 4Vb
/-4 is nsf g
real number.
Round to the nearest
\nE = \/*
Use the
= ,/Ft/s
= 5v5
= 5(2.236)
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UNIT 11 Radical Expressrons 387
1.2 Objective To simplify variable radical expressions
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Variable expressions which contain radicals do not always represent real numbers.
The variable expression at the right \/Fdoes not represent a real numberwhen x is a negative number, forexample, -4. \K-T = f 44 Not a real number
For this reason, the variables in this unit will represenl positive numbers unless other-wise stated.
A variable or a product of variables written in exponentral form is a perfect squarewhen each exponent is an even number.
To find the square root oJ a perfect square, remove the radical sign and multiply eachI
exponent Dy z.
Simplify r,66.
Remove the radical sign and multiply the exponent OV L {F = as
A variable radical expression is in simplest form when the radicand contains no factorwhich is a perfect square.
-simplity vx'.Write x7 as the product of x and a perfect \F : \,eq'xsquare.
Use the Product Property of Square Roots. = rFrRSimplify the perfect square. - xttQ
Simplify 3xttrfrE.Write the prime factorization of the coeffi- Sxt/BFyB = 3xtf*i5y6cient of the radicand in exponential form.
Write the radicand as a product of a per- = 3xy/FPfQxy)fect square and factors which do not con-tain a perfect square.
Use the Product Property of Square = 3xy/FFyot/2xyRoots.
Simplify. - 3x.2xy6{2xy= 6xzyot/2xy
Simplify \/ri6- lFWrite the prime factonzation of the coeffi- \86 -ZF = 1f Sz(x -ficient in exponential form.
Simplify. =5(x-2)= 5x - 10
388 UNIT 11 Radical Expressions
Example 5
Simplify 16-1
Solution
\/F = \/5r:E = 1/Ft. t/6 = brr/6
Example 6
Simplify y!-1
Your solution
Example 7 Example g
Simplify \tr4F Simptify \Ai6rSolution your solution\/24-F = lF.J.P - \EqTz.3x\ -\/F:p\tr:ji - 2x2t/6x
Example 9 gxampte 10
simptify 2atfi6FFd, Simptify sa\/28fl66.
Solution your solutionzatfi6at66 - 26r/2.@:sr. 6o -2at/Fa/Fd1u1 = 2a1/F4.nn\E =2a. 3. r. 6s1/Za - 6"26s ;/2a
Example 11 Example t2Simprify / 6-GTEF. Simptify \tri6 _WSolution your sotution
VT6trTTP = t/FQJ@ - 22(x + 5) :4(x+5)-4x+20
Example 13 Example 14
Simplify Simptify \frT_1IV+ 4s-
Solution your solution
-
t/r2 + 10x + 25 = \ru+ 5F= x + 5
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UNIT 11 Radical Expressions 389
1.1 Exercises
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Simplify.
1. /Td 2. \/64 3. \Ee 4. \n44
5. \/32 6. \60 7. \6' 8. ,,42
9' 6 \n8 10. 4\Ed 11. 5\Fo 12. 2\/28
13. vT5 14' \tr1 15. ,,6 16. ,fr3
17. -srtl 18. 11 vBO 19. ^45
20. \E%
21. vO 22. \/7m 23. 6\4n 24. s\/7n
25. vT05 26. v65 27. \€00 28. \re-00
2s. 5 /180 30. 7 \,tr8 31' \/250 32' \n6
33. /06- 34. vlEo- 35. \FZA 36' \844
Find the decimal approximation. Use the table on page 438.
t=t 37. tE+ol:..:J
41. \trs6
38' \re-oo 39. \,tr6d 40. v600-
42. \@ 43. \,mg 44. 1466
4s. \tr4s 46. \Fn 47. \,AA 48. /365
390 UNIT 11 Radical Expressiors
1.2 Exercises
Simplify.
49' \/F 50' \/nz sl. \/va 52' \/F
ss. \/F 54. \/ai' s5' \/FF 56' \frW
57. \EF s8' \/'v se. \trEF 60' \FW
61' \/FF 62. \/FW 63. \/Fm 64. \/nF
6s. v6OtF 66. \/W 67. \@;w-
6e. \/l6FY? 70- \EFFT 71. \MV
68. \n4TFtr 6Io6o6
72' \frrFP F
73. v6Grbit- 74. \MFV 7s. ztfid$F 76. st/x-FF
77. x\/FF 78' Y\Fp 79. q\/nFF 80. stfrIFF
81. sx1/1zFf 82. +vt/TdFF 83. 2x21/ffif 84. 3y2lfi7f
8s. \/25G;+ry 86. \/6W=W 87. \/46=4
BB. \/96= 2f- 8e. \FlZrTZ eo. {F=e6T1d
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91. \/yr@ s2. \FTA;75 e3. vitz -E T-Td
U N lT 11 Radical Expressions 391
SECTION 2 Addition and Subtraction of RadicalExpressions
2.1 Objective To add and subtract radical expressions
The Distributive Property is used tosimplify the sum or difference ofradical expressions with like radi-cands.
Radical expressions which are insimplest form and have unlike radi-cands cannot be simplified by theDistributive Property.
Simplify 4\/6 - 1O\/,
Simplify each term. 4\/8 -
Simplify the expression by using theDistributive Property.
Simplify B\ilBx - 2\hN.Simplify eachterm.
Simplify the expression by usingthe Distributive Property.
5t/2+3t/7=(5+3)rt=grto\tri - 4\E = (6 - q\/trx:2.,,8x
zt/5 + +t/V cannot be simplifiedby the DistributiveProperty.
1O\/2=4\/8-rcrt
I = ^--ri -io.rn-l Do this steP
' :;-{"G- --,-o i' mentarr''
- 4.2r/2 - tot/2= BtD - 10vtr
------------r- Do this stepl=rg-1o\.,DL--Y----:-::_1 mentally.
= _2f2
B\nu - 2\/52x = 8t/2:Fi - z\,Ev
,:;wox- --;a ."t, 3:^'ll:'*or i men1allv.
= Bv@\B - 2\E\,8: B'3\//i -r'221/u= 24\/Ex - a{u
'l = ,ro - B\tEi i Do this steP
l-:----:'-::-j mentally.
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Example 1 ExamPle 2
simptify 5\/, - sttr + 12\/, simplify 9r/5+ 3V5- 1Bv6
Solution Your solution
s\/2 - s\/7 + 12\/Z = 1 4\/E
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392 U N lT 11 Radical Expressions
Example 3 '
Simptify s\nZ - s\/n.
Solution
3\n2 - s\E = sy/Fi - 5V35 :s\/Ft/s - s\/g\/5 =3.2\/3 - 5.3r,6:6V5- 15\6= -9\6
Example 4
Simplify 2\FO - 5\8.Your solution
Example 5
Simplify 3\n2xs- - 2xt/3x.
Solution
3r/@- zat/u : 3t/F:3:F - 2xy/!i =g\/F .-FrB - zxt/u - s .2. xt/u - 2xtf3x =6xt/!i-2xt/3x:4x1f3x
Example 6
Simplify vt/N +7\/65F.
Your solution
Example 7
Simplify 2xy/8y - s\trW + z\hmSolution
2xt/8y - 3\trfr + 2th2fr =2xtPS - s\trfr + 2t/2sfr =zxt/Ft/zv - 3\/F\E + 2t/FPt/zy =2x.2t/2y -3.xt/2y +2.22.xt/2y =axt/zy - 3xt/2y a 8x1/2y :9xy/2y
Example 8
Simplify 2\/nF - aat/tze:- + a2t/75a.
Your solution
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UNIT. 11 Radical Expressions393
2.1 Exercises
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Simplify.
1. zt/7 + t/2 '2. S16+ 816 3. -3fi + 2rt
4. 4\/s - j0\6 s. -3VjT - 8\,47 6. -3vA - 5.va
7. 2t/i + a\/, 8. s\/y + Z\/i 9' 8\/i - 1o\/i
10. -5\E + z\Ea 11. -2\/i6 _ e\re6 n. _7 \/5a _ 5\6;
13. 3xt/7 - xt/2 14. 2vt/5 - gv\/3 ls. 2ay/ia _ sat/k
16. -sb\/ji - 2b\/jI 17. 3\8 - B\N 18. -4\/xy + 6\/xy
21. 2t/7 + 3t/ale. t/+s + \mi 20. \/s/ _ \,66
22. 4\/128 - 3\hZ 23. 5V18-- z\ns 24. s\/7s - 2\fl8
25. 5\/4x - 3\M 26. _s\//il + 8\/4W 27. 3\/sF _ s\EF
28. -2\/sF + s\/jz7 2e. 2xt/if _ syytf, s0. aay/b%- _ sb\/Fo
31. sxlh2x - s\EF g2. zat/soa + 7\ltrzF 33. qy\/8F-7\nBF
34. 2at/BaF - zb\trF 35. b'?\EFE .r3a2y/a6s- 36. y'z\/W + xt/FF
394 U N lT 11 Radical Expressions
Simplify.
s7. 4\/, - stq + a\E 38. 316+ B\6- 16\6
3e. 5\/i - ltF + gt/i 40. tfr-tt/x+at/i
41. 8\// - 3\fr - 8\/, 42. 8\6 - St/T - st/5
43. 8w - 4\E - e\60- 44. 2\fr2 - 4{n + ,/ts
45. -2\/i + 5\E - 4\Fs 46. -2\/8 - g\E + 3r,60 --r
3
47. 4\nd + 3\R - \,69 48. 2\fr5 - 5\/N + 2\/45 =p@
E
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4e. \/N - l/sx + 1frax so. \Ei - fiTo-t - \M ;zoo
51. 31/u + \m - 8\/75x 52. 5\F + 2\/45x - g/60t
53. 2at/tsb - at/zob + aa1/ffi 54. zb\nsa - sb\m + 2b\/2va
s5. ,t/V - 2vt/t* + xy\/t 56. atFF + 3bt/Ta7F - ab\/3
57. g\/N + aat/ab - 5b\/4ai 58. s\/FE + ay/ffi - 3\/48d6
s9. sat/T# - JFg + abt/#b 60. z\FFF - sat/e# + abt@o
UNIT 11 Radical Expressions
SECTION 3 Muttiplication and Division of RadicalExpressions
3.1 Obiective To multiply radical expressions
The Product Property of Square Roots can also be \trr\/W = yf2x:3y: \/6xyused to multiply varrable radical expressions
Simplify ({4'Multiply the radicands.
Simplify.
Note: For a ) 0, (\ftr2 - aE = a
Simplify \,ee''PZxl.Use the Product ProPertY ofSquare Roots.Multiply the radicands.Simplify.
Simplify t/zx(x + {u).Use the Distributive ytri1xProperty to removeparentheses.
Simplify 6ltr - 3x)6/2 + 4.Use the FOILmethod to removeparentheses.
T--------l. -,^ r rl r- |(\/x)':VxVxi-Vx.xl' L-------l
_ ,/F=^
--------------l\/fxz \/gIF | = \,trx'-EF I
L-- --------l
= \/64x?= \/FF: \EFt/i_ 2sx3t/i- s*r&
----------+ t/n>t=_!3!9_I-8-q)
= x;/2x + t/+F= x;f2x + t/PF- xt/2x + 2x
Do this stepmentally.
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Do this stepmentally.
Do this stepmentally.
The expressions a + b and a - b, which are the sum and difference of two terms, are
called conjugates of each other. Conjugates differ only in the sign of the secondterm.
SimplifyQ+{DQ-\,ry)The product of conlugates of the form(a + bXa - b) = a2 - b2.
SimprifyG+{DG-{v>The product o{ conjugates of the form(a+b)(a-b)=a2-b2.
6/2 - 3x)6'D. o
: f:i;:-';,,rf'*""
Q + \fr)Q - tn
='o'
_ rlv,-3
-a2=9-y
(3+r,ay)(3-{v> ,/7
396 UNIT 11 Radical Expressions
Example 1 Example 2
Simprify \/gFveW\/W Simplify Vselm%Tv-3bl
Solution Your solution
\EF \trW \/6 x-y' : tf!6 x7 y3 =\trgFvt = lfFFFf \/xy :,. 3rsyl/w = 6#yf xy
Example 3 Example 4
Simplify lulft/u + .urgol. Simplify ,fsrfr/s, - lFzsn.
Solution Your solution
t/e;6f\/ge + V-gO = \h46 + tf*aF =\Fet/o + y@Ft/ia :3ayE + sb\,€e
Example 5 Example 6
Simplify (\/a - ,/6X.r[- + \/6). Simplify (zt/i + 7)(2\/i - 7).
Solution Your solution
(\/a - {oXr/u + {D = t/F - \/F - a - b
Example 7 Example 8
simptify (2\/i - t/*D5tfr - ztfn. simplify (3\/x - t/iXsr/V - z{D.
Solution Your solution
e\,q - {D6t/x - zt/lt) =1o\/F - 4\/xy - s\/xy + 2rF =lOx-g{xy+2y
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3.2 Objective To divide radical expressions
The Quotient Property ol Square Roots
The square root of a quotient isequal to the quotient of the squareroots.
simplify vry,Rewrite the radical expression as thequotient of the square roots.
Simplify.
lf a and b are positive real numbers andl; .,8 ,E labl0, then l-=-:-and-i-= l-.' vb \/b \/b vb
r-------ll4x2 ', \/4x2 |
Vz6 l ,'/FiL-____-J
- \,@P -vzo
Do this stepmentally.
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UNIT 11 Radical Expressions
Simolifv lry-' ' ,,,1 sx,y.
Simplify the radicand.
Rewrite the radical expression asthe quotient of the square roots.
Simplify.
Multiply the numerator and denominator_f;
bv v". which eouals 1.' /^ 'V.1
The radicand in the denominator is a per-
fect square.
Simplify.The radical has been removed from thedenominator.
Simplify "; -V-l/ -r u
Multiply the numerator and de-nominator OV lA - 3, the con-jugate of t/y + S.
Simplify.
i-;vt 1 Do this step
i_:E_j mentarry
1 - 1 .vF=st0+s ,,0+s tfi-z
F----------
i- t/v-z I DothissteP
i-@-3'? I mentallY.L_*____-_-!
_./y_3y-9
l24x3y7 lgvs| 3x'v' - 'J xo
l---------ri - t/evu I
i ,/f ili
t/2"ru.,F\/Ff\/N:+ .,F I
_ 2yrt/g- ---',--
397
Do this stepmentally.
Simplify ry\/ xY
Use the Quotient Property of Square Roots.
Simplify the radicand.
Simplify the radical exPression.
A radical expression is nol considered to be in simplest form if a radical remains in the
denominator. The procedure used to remove a radical from the denominator is called
rationalizing the denominator.
tzPv.,1 ,y
=\R= \/Ft/V= 2\/x
l4W,/ry
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simolify ft2 - z .yBv.r v.r vr
^r;_ zvJ3
398 UNIT 11 Radical Expressions
Simptifv t/Z + yFF/^vz
Divide each term in the numerator by the denomi- t// + tfldF _ ,/z , \nBFnator. vT -: r1*-iUse the Quotient Property of Square Roots.
Simplify.-1+ IIY'v 2
:t + tfgF= I + ,/1T'z-1+3y
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Example 9
Simplify ry\/3x"Y
Solution
Example 10
Simptifv @.t/3xryt
Your solution
Example 11
Simplify -:g-t/2 - t/x
Solution
\,tr _ \/, . t/1+ t/x _J2-\/i \f2-\n \/r+fi-
Example 12
Simplify -!-t/Y+s
Your solution
2+t/x2-x
Example 13
simotifv Qo - ztfinvb
Solution
tm - ?lnZg _ \q_ _ ,ffi _V5 \/s t[s
Example 14
Simolifv t/nxs--s\/OxV3x
Your solution
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17t-'J+ = \/4 - 2\f25 :-2\/g-2-2.s:2-jo--B 6ori
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UNIT 11 Radical Expressions
399
3.1 Exercises
Simplify.
1. \/i.\/i
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f,c
oo()
2. \/n. \nT 3. \/s-. \rc
4. \/2. \/d 5. Vx' t/x 6. \/y. rfr
7. \/F.\/n 8. {alFF. 1;fi e. \tra$. \/d;F
10. \/W.\/TW 11. \/de3.e.\trC%- 12. \/d;F. \frTFS
t/Zft/Z - vO
t/b(t/a - \/6)
14. s(\/TZ - \,O ls. tRftfr _ \O)
17. v6(/i0'_ \/i) 18. \/d6/y - r/Te--;
le. t/e-fttr _ v/o 20.. t/to-cr/N _ G) 21. (t/i - s1,
22. (2G _ D2 23. tMrt/u- _ v66l 24. tqrtnO; _ \/i)
25. \trac . \/sab--. \frdc6 26. \/W. \/w.\/ry
27. @\fr - 2h|6t/i _ qy) 28. (sv&+ zt?)@tfr _ t/-v>
2e. (\/i - tElt{i + \O) 30. (\/* + D6/u- _ v)
13.
16.
31. (zt/i + ,fr>tst/i + 4\0) 32. (s\fr _ zt'lrs\/i _ 4\o)
400 U N lT 11 Radical Expressions
3.2 Exercises
3s. #
38. #
-frc34. vi:vb
s7. lmVga
36' #
46. Lt/2x
4e. @t/3xv3
Simplify.
33. #
39. \nsFYt/3xy
42. ,/^Wt/sxtY
51. -:Lvz-J
40. Iryt/5xY
55. J* -t/x - t/Y
44. l:t/e
4s. +
53. --j--=b+vb52. =5l-vt - J
41. \/ZFg\/1Bab4
3r3Io
47. ft'"' E- it"4-2 bv-r\ t I
oG
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50. ,/Tryt/Bxty
56' ffi
45' +
48. \/w\,trix
54. J/^YZ - |
sr. 3\'tr -_B\/, sg. 5\/3 -3_\/j 59. zytr t:_\/2\// zvtr ,,tr,
60. ,fi#tr! 61. S*tlE 62. "E#tfr
UNIT 11 Radical Expressions 401
SECTION 4 Solving Equations Containing RadicalExpressions
4.1 Objective To solve an equation containing one or more radical expressions
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An equation that contains a variable ex- rfr : 4 I naOicat
f;:""..r'".inaradicandisaradical equa- \/qTZ: yfx _t j Equations
The following property of equality is used to solve radical equations.
Property of Squaring Both Sides ol an Equation
lf two numbers are equal, then the lf a and b are real numbers and a = b,squares of the numbers are equal. then a2 : b2.
Solve \&-2 -7 =0.Rewrite the equation with the radical \/q - 2 - 7 - O
on one side of the equation and the ,/82 : Iconstant on the other side.
Square both sides of the equation. 1yF - Z1z = lzSolvethe resulting equation. x -2:49
x=5'1The solution is 51 .
Checkthesolution. Check; \/q-2-7:OWhen squaring both sides of an equa- \,qf - Z - 7 : 0tion, the resulting equation may have u * _ 7 - O
solution which is not a solution of the lp _ 7 = Ooriginal equation. 7_7=O
0:0 Atrueequation
Example 1 Example 2
Solve: 16i * 2 :5 Solve: y/4y + 3 =7
Solution Your solutiony/u+2-s check: l/u+2-s
t/3x:3 .,6'g +2-5(yEiyz=32 J*+z-s
3x:9 3+2-5X=3 5=5
The solution is 3.
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402 UNIT 11 Radical Expressions
Example 3
Solve: 0=3-\pr-
SolutlonO:3-\tri=3
-3 - - \tri=3(-3)2=(-t/Tx-S)z
9-2x-312-2x6=X
Tne solution is 6.
Example 4
Solve: y/1x-Z-s
Your solutionCheck:0=3-0=3-0:3-0:3-0=3-0=3-0=0
\tri -3\E:{-\nz -3v0\/g3
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4.2 Objective To solve application problems
Example 5
How far would a submarine periscope have to beabove the water to locate a ship 4 mi away? Theequation for the distance in miles that the lookoutcan see is d = 1.4\n, where h is the height in
feet above the surface of the water. Bound to thenearest hundredth.
Strategy
To find the height above water, replace d in theequation with the given value and solve for h.
Solution
1.4\/6 = d1.4\f n = 4
rAVn =aa
(r/-hy = (+)'I ^- 16
" - JlSd
h = 8.16
The perisrcope nnust be 8.16 ft above ihe water
Example 6
Find the length of a pendulum that makes oneswing in 2.5 s. The equation for the time for one
n-swing is T = 2n.f n, where f is the time in sec-
onds and L is the length in feet. Use 3.14 lor n.
Round to the nearest hundredth.
Your strategy
Your solution
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4.1 Exercises
UNIT 11 Radical Expressrons 403
Solve and check.
1. lV=S 2. ly :7 3. \fa = 12
4' t/a :9
7. t/+x = a 8. Jax:g 9. \/rr-4=O
10. 3- \,6t=0 11. t/qx+5=2 12. t/u+9=4
13. \/3x-2=4 14. /Sxao-t 15. t/zxll=t
16. 1/Sx1+-S 17. O:2 - \/3 - x 18. 0 = 5 - \frdTt
19. \/5x+2=O 20. 1/sx-t =O 21. ,/g^-6:-4
22. y/Sx + B = 23 23. O:1fix-S-O 24. O=1/Zxat-Z
25. \/5x-1= 1fra9 26. lix+4=\nZx-w
27. \/ii-- = \f4x - 28. \tri-g=\/2x*3
6.
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2s. \F=ZrTA = \/F - sv q s 30. \R=2iJ4 = y/P a 5y - 12
404 UNIT 11 Radical Expressions
4.2 ApplicationProblems
Solve.
1. Four added to the square root of
lhe product of f ive and a number is
equal to nine. Find the number.
How far would a submarine Peri-scope have to be above the waterto locate a ship 5 mi awaY? Theequaiion for the distance in milesthat the lookout can see is
d - 1.4Vh, where h is the heightin feet above the surface of thewater. Round to the nearest hun-dredth.
An object is dropped from a highbuilding. Find the distance theobject has fallen when the sPeed
reaches 64 ftls. The equation forthe distance is v = /-6+d, where vis the speed of the object and d isthe distance.
7. A stone is dropped from a bridgeand hits the water 1 .5 s later. How
high is the bridge? The equationlor the distance an object falls in f
1.1seconds is given bY I = ./iC,where d is the distance in feet.
Round to the nearest hundredth.
Fl 9. Find the length of a pendulum thatUiJ makes one swing in 2 s. The
equation for the time of one swing
of a pendulum is given bYlt
T - 2n /1, where f is the time in'--"tlsz'seconds and L is the length in
feet. Use 3.14 for a'. Round to thenearest hundredth.
2. The product of a number and thesquare root of two is equal to thesquare root of eighteen. Find thenumber.
How far would a submarine peri-scope have to be above the waterto locate a ship 6 mi away? Theequation for the distance in milesthat the lookout can see is
d - 1.4r,1-h wf,ere h is the heightin feet above the surface of thewater. Round to the nearest hun-dredth.
An object is droPPed from a
plane. Find the distance the ob-ject has fallen when the sPeed
reaches 512 fI/ s. The equationfor the distance is v = y/64d,where v is the speed of the objectand d is the distance.
A stone is dropped into a mine
shaft and hits the bottom 3 s later,
How deep is the mine shaft? The
equation ior the distance an objectfalls in f seconds is given bY
- frtT = J#, where d is the distance
in feet. Round to the nearest hun-dredth.
Find the length of a pendulum thatmakes one swing in 1.5 s. Theequation for the time of oneswing of a pendulum is given bY
TTT = 2n /*, where f is the time
\JIin seconds and L is the lengthin feet. Use 3.14 for n. Round tothe nearest hundredth.
4.3.
6.5.
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10.
UNIT 11 Radical Expressions 405
Review/Test
SECTION 1 t.ta Simplify f5. 1.1b Simplity /-5.
1.1c Find the decimal approximation 1.2a Simplify \\XFF.ot t/125. Use the table on page438.
1.2b Simplify \nu'y'?- 1,2c Simplify \/4rFStooI@P@
E,!cd
E SECTION 2 2.1a Simplifyalv-s\/y. 2.1b Simplify5/8-3/-50.coo
2.1c Simplify 2.1d Simplify3\/W - 2\fr?2x + s\nly 2xt/5$ - zvlTlfr - 3xyt/xy.
SECTION 3 3.1a Simplify\/W\/1uy4-. 3.1b Simplify\FWttdVOx.
406 UNIT 11 Radical Expressions
Review /Test3.1c Simplify G6/" - t/-o>. 3.1d Simplify (\/y - eXl/y + s).
3.2a simplify #
3.2c Simplify G-
g.2b Simolifv -)ry.t/2a"b'
4.1b Solve: 1/di+3=18
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C)SECTION 4 4.1a Sotve: y/sx-6=t
4.2a The square rool of the sum of two 4.2b Find the length of a pendulumconsecutive odd integers is equal that makes one swing in 3 s. Theto 10. Find the larger integer. equation for the time of one
swing of a pendulum is given byrT-
T : 2n JS, where f is the time
in seconds and L is the length infeet. Use 3.'l 4 tor n. Round tothe nearest hundredth.
UNIT 11 Radical Expressions 407
Review /TestSECTION 1
SECTION 2
1.1a Simplify 126a) 4rtc) 2\/7
1.1c Find the decimal approximatlonot 16e Use the table on page438.a) 12.124 b) 7.484c) 7.937 d) 7.398
1.2b Simplify \/6Wa) 4x2tf|yb) 4x2yEyc) 16x2t/3yd) axt/jfr
2.1a Simplify g\/a - g\,6a) -6̂ -o) -6va,c) -12\/ad) -6\/6
2.1c Simplifyz\E;-s\/4%+B\/ Baa) 38 \ree - 35 \6b) 3\ree6c) 2ByEe - 3s\,6d) 38\ree - 5\@6
3.1a Simplify \,IZF;t{A;F.a) ,6"+5a labb) 4"t6+ lZabc) 6"26+ lf1abd) otz6+ yfdab
1.1b Simplify vtOda) 6\6c) 36va
b) 7vZd) 3\,6-
b) 7vEd) 3v5
1.2a Simplifya) 3aac) 3a2
\/lTF.b) e-\/Fd) 9a2
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1.2c Simplify \ndZFsna) tx3y2tf3fyb) 8x3y2 1/2xyc) Bx6y2tf3xyd) 7 x6y2 tf2xy
2.1b Simptify 3\hZ - 2\,4na) -4vtrb) -48\/,c) 12\/Z - 16 V3d) 28\/z
2.1d Simplify2aytraF + b \/EFd - sab t/ab,a) gabt/abb) -zaby66c) aaby66 - Sa2b2
d) aabt/2ab - sabv66
3.1 b Simplify \tra%- \88;F ttra.a) -7
us6z yf 2b) , Ous6z yEac) 14a2b2 nEad) rrz5z{2a
fr
SECTION 3
408 UNIT 11 Radicat Expressions
Review/Test
3.1c Simplify v6(\6-- {Vr)a) zt/s - x\/tb) 3t/z - xt/5c) s - xt/id) 3\/, - s\/i
3.2a Simplify $v5
Simolifv 3 -.' ' a -/Ea - vo
^\ z+r/5d)7
b)
=#trc) -u lut€d) -O - 3\6
4.1a Solve: 16x-2 -4=0a)2 b)4c)8 d)6
4.2a The square root of the sum of twoconsecutive integers is equal to9. Find the smaller integer.a) 20 b) 80c) 81 d) 40
3.1d Simplify(\/a-r/rXG+\/2)a) a2-4a+4b) a2-4c) a-2d) a2+4
g.2b simorifv @\/3a4b
a) 6a3bo
b) 6aby/ac) 6a3btfabd) 6a3b2
3.2d Simolifv \frZF -- \E,/g
a) 2x-3b) 4i3^\ 2xvE - sw)3
d) 4+f
4.1b Solve: 3-B-a) 11 b)
a) 8\,6b) 5wc) 64d)8
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SECTION 4 -VbX.1
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A stone is dropped from a build-ing and hits the ground 5 s later.How high is the building? Theequation for the distance an ob-ject falls in f seconds is given by
fA, = J *, where d is the distance
in feet. Round to the nearesthundredtha) 200 ftc) 10 it
b) 400 ftd) 300 ft
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