Pre-Calculus Homework Solutions 230

# Pre-Calculus Homework Solutions 230 - 9. Let x represent...

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Unformatted text preview: 9. Let x represent the geometric mean. Page 391 Geometry Activity: Trigonometric Identities 1. Sample answer: It is of the form a2 where c 1. 1 2. cos sec ; ta1 n sin 3. cos tan y r x r y x yr rx y x 4. cos sin y , cos r y x x r , tan Multiply by the reciprocal of x . r Multiply. y2 x y2 x2 2 y2 x2 x y2 cot2 x2 y x2 y2 2 y2 x2 y x2 sin x y x y 5. tan2 Original equation x y xr ry x y x2 x x 10. Let 20 x¬ x2¬ x¬ x¬ 11. Let 18 x¬ x2¬ x¬ x¬ 12. Let Original equation cot x r y r 6. c2, cot sin y x y x b2 4 x Multiply by the reciprocal of y . r Multiply. y , cos r 1 sec2 1 r x r2 x2 1 x r , cot x y tan y , sec x 1 (x2) x2 Multiply each side by x2. x2 r2 1 r2 r2 csc2 Simplify. Substitution; y2 x2 Original equation 1 1 r y r2 y2 2 cot x y , sec r2 r y 1 r (y2) y2 x 44 792 792 28.1 x¬ RS. RS QS x 14 52 17 ¬ 25 289 ¬ y2 r2 r2 r2 Simplify. Substitution; x2 x2 Multiply each side by y2. y2 700 700 26.5 x represent the geometric mean. 14. x2 Evaluate exponents. 2 x 35 x2¬ 112 x¬ 112 or 4 7 x¬ 10.6 So RS¬ 10.6. 13. 152 202¬ x2 225 400¬ x2 625¬ x2 625¬ x 25¬ x r x Evaluate exponents. r2 324 324 18 x represent the geometric mean. PS RS ¬ 8 x¬ Original equation 2 x 81 13 2 17 169 289 144 289 144 289 12 17 x2¬ r2 x¬ x¬ 132¬ x2 15. Chapter 7 Study Guide and Review x2 169¬ x2¬ x¬ x¬ 9 92 13 Page 392 Vocabulary and Concept Check 1. 2. 3. 4. 5. 6. 7. true false; opposite; adjacent false; a right true true false; 45°-45°-90° false; depression 16. x y 17. 13 2 13 2 2 2 13 2 2 y 8. Let x represent the geometric mean. 4 x x2 x x 64 64 8 Chapter 7 232 2 x x 13 2 2 18. x y 19. z a a x 16 x x x y Pages 392–396 Lesson-by-Lesson Review 212 441 272 272 or 4 17 16.5 2(6) or 12 63 18 3 2z 2(18 3) or 36 3 ...
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## This note was uploaded on 12/19/2011 for the course MAC 1140 taught by Professor Dr.zhan during the Fall '10 term at UNF.

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