Chapter 10 Homework 1 Lesson 10-1 pages 538–541 Exercises 2. 1. Hyperbola: center (0, 0), y-intercepts at ± 5 3 , no 3 x-intercepts, the lines of symmetry are the x- and y-axes; domain: all real numbers, range: y > – 5 3 or y < . – 5 Ellipse: center (0, 0), x-intercepts at ±3 2, y-intercepts at ±6, the lines of symmetry are the x- and y-axes; domain: –3 2< –x < – 3 2, range –6 < –y < – 6. 3 3 3 10-1 2 Lesson 10-1 3. 5. Circle: center (0, 0), radius 4, x-intercepts at ±4, y-intercepts at ±4, there are infinitely many lines of symmetry; domain: –4 < –x < – 4, range: –4 < –y< – 4. Ellipse: center (0, 0), y-intercepts at ±2, x-intercepts at ±5, the lines of symmetry are the x- and y-axes; domain: –5 < –x < – 5, range: –2 < –y < – 2. 6. 4. Hyperbola: center (0, 0), y-intercepts at ± 3, no x-intercepts, the lines of symmetry are the x- and y-axes; domain: all real numbers, range: y < – 3 or y > – 3. Circle: center (0, 0), radius 7, x- and y-intercepts at ±7, there are infinitely many lines of symmetry; domain: –7 < –x < – 7, range: –7 < –y < – 7. 3 Lesson 10-1 7. 9. Hyperbola: center (0, 0), y-intercepts at ±1, the lines of symmetry are the x- and y-axes; domain: all real numbers, range: y < – –1 or y > – 1. 8. Circle: center (0, 0), radius 10, x- and y-intercepts at ±10, there are infinitely many lines of symmetry; domain: –10 < –x < – 10, range: –10 < –y < – 10. 10. Hyperbola: center (0, 0), x-intercepts at ±2, the lines of symmetry are the x- and y-axes; domain: x < – –2 or x > – 2, range: all real numbers. 10-1 Circle: center (0, 0), radius 2, x- and y-intercepts at ±2, there are infinitely many lines of symmetry; domain: –2 < –x < – 2, range: –2 < –y< – 2. 4 Lesson 10-1 11. 13. Ellipse: center (0, 0), x-intercepts at ±4, y-intercepts at ±2, the lines of symmetry are the x- and y-axes; domain: –4 < – x< – 4, range: –2 < – y< – 2. Ellipse: center (0, 0), x-intercepts at ±1, y-intercepts at ± 1 , the lines of symmetry 3 are the x- and y-axes; domain: 12. 1 y 1. –1 < –x < – 1, range: 3 < – < –3 Circle: center (0, 0), radius 5, xand y-intercepts at ± 5, there are infinitely many lines of symmetry; domain: – 5 < –x< – 5, range: – 5 < –y < – 5. 10-1 5 Lesson 10-1 16. 14. Hyperbola: center (0, 0), x-intercepts at ±6, the lines of symmetry are the x- and y-axes; domain: x < – –6 or x > – 6, range: all real numbers. 15. Ellipse: center (0, 0), x-intercepts at ±2, y-intercepts at ±6, the lines of symmetry are the x- and y-axes; domain: –2 < –x < – 2, range: –6 < –y < – 6. 17. center (0, 0), x-intercepts at ±3, y-intercepts at ±2; domain: –3 < –x < – 3, range: –2 < –y < –2 Hyperbola: center (0, 0), y-intercepts at ± 1 , 2 the lines of symmetry are the x- and y-axes; 1 1 domain: all real numbers, range: y < – – or y > – . 2 10-1 2 6 Lesson 10-1 18. center (0, 0), no x-intercepts, y-intercepts at 42; domain: all real numbers, range: y < – –2 or y > –2 19. center (0, 0), x-intercepts at 43, no y-intercepts; domain: x < – –3 or x > – 3, range: all real numbers 23. 19 24. 17 25. 18 26. 20 27. 21 28. 22 20. center (0, 0), x-intercepts at 48, y-intercepts at 44; domain: –8 < –x< – 8, 29. range: –4 < –y < –4 21. center (0, 0), x-intercepts at 43, y-intercepts at 45; domain: –3 < –x< – 3, range: –5 < –y < –5 Hyperbola: center (0, 0), x-intercepts 22. center (0, 0), no x-intercepts, y-intercepts at 43; domain: ±4, the lines of symmetry are the xall real numbers; range: y < and y-axes; domain: x < – –3 or y > –3 – –4 or x > – 4, range: all real numbers. 10-1 7 Lesson 10-2 24. (0, 0), (6, 0), x = –6 26. (0, 0), (3, 0), x = –3 28. (0, 0), (0, 1), y = –1 25. (0, 0), (0, –1), y = 1 27. (0, 0), 25 , 0 , x = – 25 29. (0, 0), (0, –1), y = 1 4 4 8 Lesson 10-2 30. (2, 0), (2, 1), y = –1 32. (–2, 4), –2, 17 , y = 15 34. (4, 0), (4, –6), y = 6 31. (0, 0), (–2, 0), x = 2 33. (–3, 0), – 3 , 0 , x = – 9 35. (3, –1), (6, –1), x = 0 4 2 10-2 4 2 9 Lesson 10-2 36. x = 1 y2 43. x = – 1 y2 37. y 44. y = 1 x2 38. y 39. x 40. x 41. y 42. 12 1 2 = x 400 = – 1 x2 20 = – 1 y2 28 = – 1 y2 36 = – 5 x2 56 8 48. 4 45. x = y2 46. 49. 47. 50. 10 Lesson 10-3 24. (–6, 0), 11 29. 32. 30. 33. 25. (–2, –4), 16 26. (3, 7), 4 6 27. 28. 31. 34. 10-3 11 Lesson 10-3 pages 552–554 Exercises 12. (x + 1)2 + (y – 3)2 = 81 1. x2 + y2 = 100 13. x2 + (y + 5)2 = 100 2. (x + 4)2 + (y + 6)2 = 49 14. (x – 3)2 + (y – 2)2 = 49 3. (x – 2)2 + (y – 3)2 = 20.25 15. (x + 6)2 + (y – 1)2 = 20 4. (x + 6)2 + (y – 10)2 = 1 16. (x – 5)2 + y2 = 50 5. (x – 1)2 + (y + 3)2 = 100 17. (x + 3)2 + (y – 4)2 = 9 6. (x + 5)2 + (y + 1)2 = 36 18. (x – 2)2 + (y + 6)2 = 16 7. (x + 3)2 + y2 = 64 19. (1, 1), 1 8. (x + 1.5)2 + (y + 3)2 = 4 20. (–2, 10), 2 9. x2 + (y + 1)2 = 9 21. (3, –1), 6 10. (x + 1)2 + y2 = 1 22. (–3, 5), 9 11. (x – 2)2 + (y + 4)2 = 25 23. (0, –3), 5 10-3 12 Lesson 10-3 58. (0, 4), 66. parabola; x = (y + 2)2 + 3; 11 59. (–5, 0), 3 2 60. (–2, –4), 5 61. (–3, 5), 2 38 62. (–1, 0), 2 67. Let P(x, y) be any point on the circle centered at the origin and having radius r. If P(x, y) is one of the points (r, 0), (–r, 0), 64. (0, 2), 2 5 (0, r), or (0, –r), substitution shows that 65. circle; (x – 4)2 + (y – 3)2 = 16; x2 + y2 = r 2. If P(x, y) is any other point on the circle, drop a perpendicular PK from P to the x-axis (K on the x-axis). OPK is a right triangle with legs of lengths |x| and |y| and with hypotenuse of length r. By the Pythagorean Theorem, |x|2 + |y|2 = r 2. But |x|2 = x2 and |y|2 = y2. So x2 + y2 = r 2. 63. (3, 1), 6 10-3 13 Lesson 10-4 pages 559–561 Exercises 1. x2 + y2 =1 9 16 x2 2. 4 + y2 = 1 x2 3. 9 + y2 = 1 y2 2 4. x + 36 = 1 y2 x2 5. + 49 = 1 16 y2 x2 6. + =1 25 36 y2 x2 7. + 4 =1 81 2 y2 8. x + =1 25 9 y2 x2 9. + =1 2.25 0.25 10. 11. 12. 13. 14. 15. 16. 17. y2 x2 + =1 256 64 x2 + y2 = 1 100 36 y2 x2 + 25 = 1 12.25 y2 x2 + 49 = 1 196 y2 2 x + 16 = 1 y2 x2 + =1 256 12.25 y2 x2 + 400 = 1 900 y2 2 x + 6.25 = 1 18. (0, 5), (0, – 5) 19. (0, 4), (0, –4) 14 Lesson 10-4 20. (4 2, 0), (–4 21. (8, 0), (–8, 0) 2, 0) 22. (0, 6), (0,–6) 23. (0, 6), (0, – 24. (2 6) 3, 0), (–2 3, 0) 25. (9, 0), (–9, 0) 15 Lesson 10-4 26. (3 15, 0), (–3 15, 0) 33. ( 5, 0), (– 34. (0, 2 3), (0, –2 3) 35. (0, 4 2), (0, –4 2) 36. (0, 27. 28. 29. 30. 31. 32. x2 100 x2 64 x2 89 x2 4 x2 245 x2 514 y2 + 64 = 1 + + + + + y2 =1 128 y2 =1 64 y2 20 = 1 y2 =1 49 y2 =1 225 41. a. 0.9; 5, 0) 37. (0, 2 21), (0, – 7), (0, –2 21) 7) b. 0.1; 38. (0, 1), (0, –1) 39. (–3, 8), (–3, 2) 40. (–2, 2), (–2, – 2) c. The shape is close to a circle. d. The shape is close to a line segment. 10-4 16 Lesson 10-4 x2 y2 42. + =1 20.25 4 47. 43. a. Yes; since c2 = a2 – b2, if the foci are close to 0, then c2 will be close to 0 and a2 will be close to b2. This means a will be close to b and hence the ellipse will be close to a circle. b. If F1 and F2 are considered distinct pts., then a circle is not an ellipse. If F1 and F2 are the same pt., then a circle is an ellipse. y2 x2 44. + 4 =1 9 x2 45. + y2 = 1 16 y2 2 46. x + 9 = 1 y2 x2 + 16 = 1 4 48. The vertices are the points farthest from the center and the co-vertices are the points closest to the center. 49. Check students’ work. 50. 51. 52. 53. 54. 55. 10-4 y2 x2 + 3 4 y2 x2 + 4 25 y2 x2 + 81 121 x2 + 702.25 y2 x2 + 169 144 y2 x2 + 256 324 =1 =1 =1 y2 210.25 = 1 =1 =1 17 Lesson 10-5 pages 566–568 Exercises 1. 3. 5. 4. 6. 2. 10-5 18 Lesson 10-5 7. 9. 8. 10. (0, 11. (0, 97), (0, – 113) 97) 12. ( 10-5 113), (0, – 265, 0), (– 265, 0) 19 Lesson 10-5 y2 x2 – =1 96,480 69,169 y2 x2 20. – =1 240,000 10,000 2 y2 x 21. – =1 170,203,465 192,432,384 y2 x2 22. – =1 11 12 5.270 × 10 1.865 × 10 2 2 y 23. x – =1 16 9 2 y2 24. – x =1 25 144 2 25. y2 – x = 1 3 2 26. x – y2 = 1 4 19. 27. 30. 2 y2 – x =1 20.25 4 28. 2 31. y – x2 = 1 9 29. 10-5 20 Lesson 10-6 pages 573–576 Exercises 1. 2. 3. 4. 5. 6. 7. 8. 9. (y – 1)2 (x + 2)2 + 4 9 2 (y – 3)2 (x – 5) + 36 16 (y + 4)2 x2 + 25 = 1 36 (y + 6)2 (x – 3)2 + 49 9 (y + 3)2 (x + 3)2 – 9 16 2 (x – 4)2 (y + 3) – 32 4 (y – 2)2 (x + 1)2 – 40 9 (x + 1)2 (y + 1)2 – 56 25 2 (y – 1)2 x – =1 25 16 =1 =1 y2 (x – 150)2 10. – 21,204 = 1 1296 y2 (x – 175)2 11. – 28,689 = 1 1936 12. y = (x – 4)2 + 3; parabola, vertex (4, 3) =1 =1 =1 13. (x + 6)2 + y2 = 81; circle, center (–6, 0), radius 9 =1 =1 10-6 21 Lesson 10-6 14. (y – 3)2 (x + 1)2 + = 1; ellipse, 9 3 center (–1, 3), foci (–1, 3 ± 1)2 3)2 15. (x – + (y + = 13; circle, center (1, –3), radius 13 6 ) 16. (y – 2)2 – (x – 3)2 = 1; hyperbola, center (3, 2), foci (3, 2 ± 2) 17. (x – 1)2 – (y + 1)2 = 1; hyperbola, 4 center (1, –1), foci (1 ± 10-6 5 , –1) 22 Lesson 10-6 18. x2 + (y + 7)2 = 36; circle, center (0, –7), radius 6 19. x – 3 = 1 (y – 2)2; parabola, 2 vertex (3, 2) 20. (y – 3)2 (x + 2)2 + = 1; ellipse, 4 9 center (–2, 3), foci (–2 ± 5, 3) 21. (x + 3)2 – (y – 5)2 = 1; hyperbola, center (–3, 5), foci (–3 ± 2, 5) 10-6 23 Lesson 10-6 y2 (x – 1)2 22. + 4 = 1; ellipse, 16 center (1, 0), foci (1 ± 2 3, 0) y2 x2 24. Translate the equation – 8 = 1, 16 a hyperbola centered at (0, 0), 3 units left. 25. a. hyperbola b. line 26. a. h is added to each x-coordinate, and k is added to each y-coordinate. b. The lengths of the major and minor axes are unchanged; the x-coordinates of the 2 2 x (y + 3) vertices are increased (or decreased) by 23. 4 – = 1; hyperbola, 9 the same amount, and the same is true center (0, –3), foci (± 13, –3) for the y-coordinates. A similar remark holds for the co-vertices. 10-6 24