A-51 Answers to Selected Exercises 73. £ -4 6 1§ 75. The difference does not exist. 77. c 3 4 -4 48d 79. c -9 10 3 6d 81. £ -2 3 6 5 4 -1 -3 -4 -2§ 83. c 3 -5 -1 2d 85. ≥ 2 3 1 3 - 2 3 0 0 1 - 1 3 - 2 3 1 3¥ 87. E A2 3 , 7 12B F 89. 51-3, 2, 026 Chapter 9 Test [9.1] 1. 514, 326 2. E Q3y - 7 2 , yR F; infinitely many solutions 3. ∅; inconsistent system 4. 511, 226 5. 512, 0, -126 [9.2] 6. 515, 126 7. 515, 3, 626 [9.1] 8. y = 2x2 - 8x + 11 9. 22 units from Toronto; 56 units from Montreal; 22 units from Ottawa [9.3] 10. -58 11. -844 12. 51-6, 726 13. 511, -2, 326 [9.4] 14. 2 x + 3 + 7 x - 1 15. 2 x + -2 x + 1 + -1 1x + 122 [9.5] 16. 511, 22, 1-1, 22, 11, -22, 1-1, -226 17. 513, 42, 14, 326 18. 5 and -6 65. y x –3 6 x + y 6 2x – y 3 6 0 67. x2 + y … 1 x - 2y 64 69. 3 units of food A and 4 units of food B; $1.02 per serving 71. a = 5, x = 3 2 , y = 0, z = 9 [9.6] 19. x y –4 4 6 –4 4 0 x – 3y ≥ 6 y2 ≤ 16 – x2 20. maximum of 42 at 112, 62 21. 0 VIP rings and 24 SST rings; $960 [9.7] 22. x = -1, y = 7, w = -3 23. £ 8 0 15 3 -11 19§ 24. The sum does not exist. 25. c -5 19 16 2d 26. The product cannot be calculated. 27. A [9.8] 28. c -2 -3 -5 -8d 29. The inverse does not exist. 30. £ -9 -2 4 1 1 -1 -4 0 1§ 31. 51-7, 826 32. 510, 5, -926 61. E A 23, 2iB , A 23, -2iB , A -23, 2iB , A -23, -2iB F 63. yes; EQ8 - 8 241 5 , 16 + 4241 5 R , Q 8 + 8241 5 , 16 - 4241 5 RF Chapter 10 Analytic Geometry 10.1 Exercises 1. (a) D (b) B (c) C (d) A (e) F (f) H (g) E (h) G 3. 12, -12; 12, 12; y = -3; x = 2; 1-∞, ∞2; 3-1, ∞2 In Exercises 5–21, we give the domain and then the range. 5. y x (–4, 0) x + 4 = y2 –2 4 2 0 3-4, ∞2; 1-∞, ∞2 7. y x 0 9 x = (y – 3)2 (0, 3) 30, ∞2; 1-∞, ∞2 9. y x 0 (2, 4) x – 2 = (y – 4)2 32, ∞2; 1-∞, ∞2 11. y x (2, 1) x – 2 = –3(y – 1)2 –1 0 1-∞, 24; 1-∞, ∞2 13. y x (0, –3) x = (y + 3)2 0 – 2 1 1-∞, 04; 1-∞, ∞2 15. y x x = y2 + 4y + 2 (–2, –2) 2 0 3-2, ∞2; 1-∞, ∞2 17. y x x = –4y2 – 4y + 3 3 0 (4, – )1 2 1-∞, 44; 1-∞, ∞2 19. y x (1, 2) 0 3 2x – y2 + 4y – 6 = 0 31, ∞2; 1-∞, ∞2 35. y2 = 20x 37. x2 = y 39. x2 = y 41. y2 = 4 3 x 43. 1x - 422 = 81y - 32 45. 1y - 622 = 281x + 52 21. y x −x = 3y2 + 6y + 2 (1, –1) −11 −2 −3 3 0 1-∞, 14; 1-∞, ∞2 23. 10, 62; y = -6; x = 0 25. A0, - 1 16B ; y = 1 16 ; x = 0 27. 1-1, 02; x = 1; y = 0 29. A - 1 128 , 0B ; x = 1 128 ; y = 0 31. 14, 32; x = -2; y = 3 33. 17, -12; y = -9; x = 7 47. −4 −10 4 2 y1 = −1 + Ä x + 7 3 y2 = −1 − Ä x + 7 3 49. −4 −10 4 2 y1 = −1 + Ë−x − 2 y2 = −1 − Ë−x − 2
RkJQdWJsaXNoZXIy NjM5ODQ=