1.2e: Exercises - SqRP, CTS, QF
- Page ID
- 45461
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)A: Square Root Property
Exercise \(\PageIndex{A}\)
\( \bigstar \) Solve each equation by the square root property
1. \(x ^ { 2 } = 81 \\[4pt] \) 2. \(x ^ { 2 } = 1 \\[4pt] \) 3. \(y ^ { 2 } = \dfrac { 1 } { 9 } \\[4pt] \) 4. \(y ^ { 2 } = \dfrac { 1 } { 16 } \\[4pt] \) |
5. \(x ^ { 2 } = 12 \\[4pt] \) 6. \(x ^ { 2 } = 18 \\[4pt] \) 7. \(16 x ^ { 2 } = 9 \\[4pt] \) 8. \(4 x ^ { 2 } = 25 \\[4pt] \) |
9. \(2 t ^ { 2 } = 1 \\[4pt] \) 10. \(3 t ^ { 2 } = 2 \\[4pt] \) 11. \(x ^ { 2 } - 16=0 \\[4pt] \) 12. \(x ^ { 2 } - 36=0 \\[4pt] \) |
13. \(x ^ { 2 } - 40 = 0 \\[4pt] \) 14. \(x ^ { 2 } - 24 = 0 \\[4pt] \) 15. \(x ^ { 2 } + 1 = 0 \\[4pt] \) 16. \(x ^ { 2 } + 100 = 0 \\[4pt] \) |
- Answers to Odd Exercises:
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1. \(\pm 9 \)
3. \(\pm \frac{1}{3} \)
5. \(\pm 2 \sqrt { 3 } \)
7. \(\pm \frac { 3 } { 4 } \)
9. \(\pm \frac { \sqrt { 2 } } { 2 } \)
11. \(-4,4 \)
13. \(\pm 2 \sqrt { 10 } \)
15. \(\pm i \)
\( \bigstar \) Solve each equation by the square root property
21. \(9 y ^ { 2 } - 1 = 0 \\[4pt] \) 22. \(4 y ^ { 2 } - 25 = 0 \\[4pt] \) 23. \(5 x ^ { 2 } - 1 = 0 \\[4pt] \) 24. \(6 x ^ { 2 } - 5 = 0 \\[4pt] \) |
25. \(8 x ^ { 2 } + 1 = 0 \\[4pt] \) 26. \(12 x ^ { 2 } + 5 = 0 \\[4pt] \) 27. \(x ^ { 2 } - \dfrac { 4 } { 9 } = 0 \\[4pt] \) 28. \(x ^ { 2 } - \dfrac { 9 } { 25 } = 0 \\[4pt] \) |
29. \(y ^ { 2 } + 6 = 2 \\[4pt] \) 30. \(y ^ { 2 } + 8 = 7 \\[4pt] \) 31. \(x ^ { 2 } - 5 = 3 \\[4pt] \) 32. \(t ^ { 2 } - 14 = 4 \\[4pt] \) |
33. \(3x ^ { 2 } + 25 = 1 \\[4pt] \) 34. \(2x ^ { 2 } + 81 = 31 \\[4pt] \) 35. \(5 y ^ { 2 } +7 = 9 \\[4pt] \) 36. \(3 x ^ { 2 } +4 = 5 \\[4pt] \) |
- Answers to Odd Exercises:
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21. \(- \frac { 1 } { 3 } , \frac { 1 } { 3 } \)
23. \(\pm \frac { \sqrt { 5 } } { 5 } \)
25. \(\pm \frac { \sqrt { 2 } } { 4 } i \)
27. \(\pm \frac { 2 } { 3 } \)
29. \(\pm 2 i \)
31. \(\pm 2 \sqrt { 2 } \)
33. \(\pm 2 i \sqrt { 2 } \)
35. \(\pm \frac { \sqrt { 10 } } { 5 } \)
\( \bigstar\) Solve each equation by the square root property
41. \(( x - 2 ) ^ { 2 } - 1 = 0 \\[4pt] \) 42. \(( x + 1 ) ^ { 2 } - 4 = 0 \\[4pt] \) 43. \(( u - 5 ) ^ { 2 } - 25 = 0 \\[4pt] \) 44. \(( u + 2 ) ^ { 2 } - 4 = 0 \\[4pt] \) 45. \(( x + 7 ) ^ { 2 } - 4 = 0 \\[4pt] \) |
46. \(( x + 9 ) ^ { 2 } - 36 = 0 \\[4pt] \) 47. \(( x - 5 ) ^ { 2 } - 20 = 0 \\[4pt] \) 48. \(( x + 1 ) ^ { 2 } - 28 = 0 \\[4pt] \) 49. \(( 3 t + 2 ) ^ { 2 } + 6 = 0 \\[4pt] \) 50. \(( 3 t - 5 ) ^ { 2 } + 10 = 0 \\[4pt] \) |
51. \(4 ( y - 2 ) ^ { 2 } - 9 = 0 \\[4pt] \) 52. \(9 ( y + 1 ) ^ { 2 } - 4 = 0 \\[4pt] \) 53. \(4 ( 3 x + 1 ) ^ { 2 } - 27 = 0 \\[4pt] \) 54. \(9 ( 2 x - 3 ) ^ { 2 } - 8 = 0 \\[4pt] \) 55. \(2 ( 3 x - 1 ) ^ { 2 } + 3 = 0 \\[4pt] \) |
56. \(5 ( 2 x - 1 ) ^ { 2 } + 2 = 0 \\[4pt] \) 57. \(3 \left( y - \dfrac { 2 } { 3 } \right) ^ { 2 } - \dfrac { 3 } { 2 } = 0 \\[4pt] \) 58. \(2 \left( 3 y - \dfrac { 1 } { 3 } \right) ^ { 2 } - \dfrac { 5 } { 2 } = 0 \\[4pt] \) 59. \(- 3 ( t - 1 ) ^ { 2 } + 12 = 0 \\[4pt] \) 60. \(- 2 ( t + 1 ) ^ { 2 } + 8 = 0 \\[4pt] \) |
- Answers to Odd Exercises:
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41. \(1, 3 \)
43. \(0,10\)
45. \(-9,-5 \)
47. \(5 \pm 2 \sqrt { 5 } \)
49. \(- \frac { 2 } { 3 } \pm \frac { \sqrt { 6 } } { 3 } i \)
51. \(\frac { 1 } { 2 } , \frac { 7 } { 2 } \)
53. \(\frac { - 2 \pm 3 \sqrt { 3 } } { 6 } \)
55. \(\frac { 1 } { 3 } \pm \frac { \sqrt { 6 } } { 6 } i \)
57. \(\frac { 4\pm 3 \sqrt { 2 } } { 6 } \)
59. \(-1,3 \)
B: Complete the Square
Exercise \(\PageIndex{B}\)
\( \bigstar \) Determine the constant that should be added to the binomial and then complete the square
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- Answers to Odd Exercises:
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61. \(x ^ { 2 } - 2 x + 1 = ( x - 1 ) ^ { 2 } \)
63. \(x ^ { 2 } + 10 x + 25 = ( x + 5 ) ^ { 2 } \)65. \(x ^ { 2 } + 7 x + \frac { 49 } { 4 } = \left( x + \frac { 7 } { 2 } \right) ^ { 2 } \)
67. \(x ^ { 2 } - x + \frac { 1 } { 4 } = \left( x - \frac { 1 } { 2 } \right) ^ { 2 } \)69. \(x ^ { 2 } + \frac { 2 } { 3 } x + \frac { 1 } { 9 } = \left( x + \frac { 1 } { 3 } \right) ^ { 2 } \)
\( \bigstar \) Solve each equation by completing the square
71. \(x ^ { 2 } + 2 x = 8 \\[4pt] \) 72. \(x ^ { 2 } - 8 x =- 15 \\[4pt] \) 73. \(y ^ { 2 } + 2 y = 24 \\[4pt] \) 74. \(y ^ { 2 } - 12 y =- 11 \\[4pt] \) 75. \(x^{2}-4 x-1=15 \\[4pt] \) 76. \(x^{2}-12 x+8=-10 \\[4pt] \) |
77. \(x(x+1)-11(x-2)=0 \\[4pt] \) 78. \((x+1)(x+7)-4(3 x+2)=0 \\[4pt] \) 79. \(2 y ^ { 2 } - y - 1 = 0 \\[4pt] \) 80. \(2 y ^ { 2 } + 7 y - 4 = 0 \\[4pt] \) 81. \(x^{2}+6 x-1=0 \\[4pt] \) 82. \(x^{2}+8 x+10=0 \\[4pt] \) b |
83. \(x^{2}-2 x-7=0 \\[4pt] \) 84. \(x^{2}-6 x-3=0 \\[4pt] \) 85. \(y^{2}-2 y+4=0 \\[4pt] \) 86. \(y^{2}-4 y+9=0 \\[4pt] \) 87. \(t^{2}+10 t-75=0 \\[4pt] \) 88. \(t^{2}+12 t-108=0 \\[4pt] \) |
- Answers to Odd Exercises:
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71. \(-4,2 \)
73. \(-6,4\)
75. 2\(\pm 2 \sqrt{5} \)
77. 5\(\pm \sqrt{3} \)
79. \(- \frac { 1 } { 2 } , 1 \)
81. \(-3 \pm \sqrt{10} \)
83. 1\(\pm 2 \sqrt{2} \)
85. 1\(\pm i \sqrt{3} \)
87. \(-15,5 \)
\( \bigstar \) Solve each equation by completing the square
91. \(t ^ { 2 } + 3 t = 28 \\[4pt] \) 92. \(t ^ { 2 } - 7 t =- 10 \\[4pt] \) 93. \(x^{2}+x-1=0 \\[4pt] \) 94. \(x^{2}+x-3=0 \\[4pt] \) 95. \(y^{2}+3 y-2=0 \\[4pt] \) 96. \(y^{2}+5 y-3=0 \\[4pt] \) |
97. \(x^{2}+3 x+5=0 \\[4pt] \) 98. \(x^{2}+x+1=0 \\[4pt] \) 99. \(y^{2}=(2 y+3)(y-1)-2(y-1) \\[4pt] \) 100. \((2 y+5)(y-5)-y(y-8)=-24 \\[4pt] \) 101. \(x^{2}-7 x+\dfrac{11}{2}=0 \\[4pt] \) 102. \(x^{2}-9 x+\dfrac{3}{2}=0 \\[4pt] \) |
103. \(t^{2}-\dfrac{1}{2} t-1=0 \\[4pt] \) 104. \(t^{2}-\dfrac{1}{3} t-2=0 \\[4pt] \) 105. \(u^{2}-\dfrac{2}{3} u-\dfrac{1}{3}=0 \\[4pt] \) 106. \(u^{2}-\dfrac{4}{5} u-\dfrac{1}{5}=0 \\[4pt] \)
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- Answers to Odd Exercises:
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91. \(-7,4 \)
93. \(\frac{-1 \pm \sqrt{5}}{2} \)
95. \(\frac{-3 \pm \sqrt{17}}{2} \)
97. \(-\frac{3}{2} \pm \frac{\sqrt{11}}{2} i \)
99. \(\frac{1 \pm \sqrt{5}}{2} \)
101. \(\frac{7 \pm 3 \sqrt{3}}{2} \)
103. \(\frac{1 \pm \sqrt{17}}{4} \)
105. \(-\frac{1}{3}, 1 \)
\( \bigstar \) Solve each equation by completing the square
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- Answers to Odd Exercises:
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111. 1\(\pm 2 i \)
113. \(\frac{2 \pm \sqrt{5}}{2} \)
115. \(\frac{-3 \pm \sqrt{6}}{3} \)
117. \(\frac{3 \pm 2 \sqrt{6}}{2} \)
119. \(1,-\frac{2}{3} \)
121. \(\frac{-1 \pm \sqrt{10}}{3} \)
123. \(\frac{1 \pm \sqrt{17}}{4} \)
125. \(\frac{-1 \pm i\sqrt{5}}{3} \)
127. \(- \frac { 1 } { 2 } , 1 \)
129. \(\frac{5 \pm \sqrt{21}}{2} \)
131. \(\frac{3 \pm \sqrt{5}}{4} \)
133. \(\frac{2 \pm \sqrt{22}}{6} \)
135. \( \frac{1}{3}, \frac{2}{3} \)
C: Quadratic Formula
Exercise \(\PageIndex{C}\)
\( \bigstar \) Solve each equation using the Quadratic Formula
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- Answers to Odd Exercises:
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141. \(-2,8 \\[4pt] \)
143. \(-4, \frac{1}{2} \)
145. \(4,5 \)
147. \(\frac{3}{4} \)
149. \(\frac{5 \pm \sqrt{21}}{2} \)
151. \(-4\pm \sqrt{11} \)
153. \(\frac{1}{5} \pm \frac{2}{5} i \)
155. \(8\pm \sqrt{2} \)
157. \(\frac{2 \pm \sqrt{10}}{2} \)
\( \bigstar \) Solve each equation using the Quadratic Formula
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- Answers to Odd Exercises:
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161. \(\pm \frac{3}{2} \)
163. \(0, \frac{6}{5}\)
165. \(\pm 3 \sqrt{2} \)
167. \(\pm 2 i \sqrt{3} \)
169. \(\pm \frac{i \sqrt{6}}{3} \)
171. \(1\pm 3 i \)
173. \(\frac{5 \pm 3 \sqrt{3}}{2} \)
175. \(\frac{1}{6} \pm \frac{\sqrt{23}}{6} i \)
\( \bigstar \) Solve each equation using the Quadratic Formula
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- Answers to Odd Exercises:
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181. \(-5 \pm \sqrt{22} \)
183. \(\frac{1}{8} \pm \frac{\sqrt{7}}{8} i \)
185. \(x \approx-1.4 \\[4pt] \) or \(x \approx 1.9 \)
187. \(x \approx 0.2 \pm 1.2 i \)
\( \bigstar \) Solve each equation using the Quadratic Formula
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- Answers to Odd Exercises:
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191. \(-2 \pm 3 i \)
193. \(\frac{-1 \pm \sqrt{2}}{2} \)
195. \(\frac{-3 \pm \sqrt{33}}{4} \)
197. \(\pm \sqrt{6} \)
199. \(-1 \pm \sqrt{7}\)
201. \(\frac{1}{2} \pm \frac{1}{2} i \)
203. \(1\pm \frac{\sqrt{3}}{3} i \)
205. \(\frac{1}{2} \pm i \)
D: Factor and Solve (Sum and Difference of Cubes)
Exercise \(\PageIndex{D}\)
\( \bigstar \) Solve.
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- Answers to Odd Exercises:
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211. \( \{ 2, -1 \pm i\sqrt{3} \} \)
213. \( \{ -\frac{3}{4}, \frac{3}{8} \pm \frac{3\sqrt{3}}{8}i \} \)
215. \( \{ \frac{5}{2}, -\frac{5}{4} \pm \frac{5\sqrt{3}}{4}i \} \)
217. \( \{0, \; 3, \; -\frac{3}{2} \pm \frac{3\sqrt{3}}{2}i \} \)
219. \( \{ \pm \frac{1}{3} , \frac{1}{6} \pm \frac{\sqrt{3}}{6}i, -\frac{1}{6} \pm \frac{\sqrt{3}}{6}i \} \)
E: The Discriminant
Exercise \(\PageIndex{E}\)
\( \bigstar \) Calculate the discriminant and use it to determine the number and type of solutions. Do not solve.
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- Answers to Odd Exercises:
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221. \(-3 \); two complex solutions
223. \(16 \); two rational solutions
225. \(-23 \); two complex solutions227. \(72\); two irrational solutions
229. \(25 \); two rational solutions
231. \(2 \); two irrational solutions233. \(37 \); two irrational solutions
235. \(0 \); one rational solution
\( \bigstar \\[4pt] \)