Exercise Set 13.2Vocabulary Review 1. vertical 2. complete the square, vertex 3. horizontal 4. right 5. left Problems 1. 3.

7.

11.

13. 15.

17. 19.

21. 23.

25. y 4 (x 2) 1 27. y = −3(x + 2) + 329. x = 4(y( − 1)2 − 4 31. x = − 1_3 (_ y( + 5)3 + 333. y = −8_

9 (_ x − 3)2 + 8 35. y = 1_3 (_ x − 1)2 − 3

37. x = −4_9 (_ y( − 2)2 + 4 39. x = 7_4 (_ y( + 4)2 − 7

41. Apple: 4,050 students; Dell: 8,400 students 43. a. Vertex (80, 70), landing (160, 0)

b. y = ax(160 − x) or y = −ax2 + 160ax c. y = 7 ___ 640 x(160 − x) or y = − 7 ___ 640 x2 + 7 _ 4 x 45. −7, −1

47. −4, 6 49. x-intercepts = −3, 3, y-intercepts = −2, 2 51. x-intercepts = −√

—√√5 , √—

√√5 , y-intercepts = −4, 4 53. ±8√—

√√2 _____3

55. ±5√—

√√3 _____2

Find the Mistake 1. Th e line x = − b __ 2a is called the line of symmetry a parabola. 2. A parabola that has two x-intercepts must have theform y = a(x − k) 2 + h. 3. A parabola that has two y-interceptsmust be a horizontal parabola of the form x = a(y( − k)2 + h. 4. A parabola that has a vertex of (4, 5) and x-intercepts of (0, 2) and (0, 6) will open down.

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