Algebra 1 Common Core Student Edition, Grade 8-9

17. f(x) = x2, f(x) = - 3 x 2, f(x) = 5x2


18. f(x) = -§ x 2, f(x) = —2x2, f(x) = —4x2

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29. domain: all real numbers; range: f(x) > 6
    31. domain: all real numbers; range: y < - 9
    33. Answers will vary. Sample: If a > 0, the parabola
    opens upward. If a < 0, the parabola opens downward.
    The vertex of the parabola is (0, c). 35. A
    37a. g(x) = 3x2 + 6 ; the graph of g(x) is shifted up
    4 units and is narrower than the graph of f(x).

.(2 ,

domain: all real numbers;

range: f(x) > 0

domain: all real numbers;

range: y < 0

Exercises 7 3); m a xim u m 9. (2, 0); m in im u m

domain: all real numbers;

range: f(x) a 0

b. h(x) = 9x 2 + 2; the graph of h(x) is narrower than the

graph of f(x). c. Multiplying a quadratic function by a

number shifts the graph up or down and changes the

width of the parabola. Multiplying the x value of a

quadratic function by a number only changes the width of

the parabola.

41.

1

Ww m i i i i r i | T

vertex: (0, 3) vertex: (0, - 6 )

axis of symmetry: x = 0 axis of symmetry: x = 0

43. M 45. M 47a. a > 0 b. |a| > 1 49a. graph of a
    parabola in the first quadrant, pointing down, with
    intercepts (0, 135) and (11. 6 , 0) and passing through
    ( 6 , 99). b. 0 < x < 9; the side length of the square
    window must be less than the width of the wall,
    c. 54 < y < 135; as the side length of the window
    increases from 0 to 9, the area of the wall without the
    window decreases from 135 to 54. 51. I 53. F
    55. 3r(5r+ 1)(2r+ 3) 56. (3qr 2 - 2)(5q - 6 )
    57. (7b 3 + 1 )(b + 2) 58. 0.75 59. -0.4 60. - |
    61. £ 6 2 .1 6 3 .- 2

Lesson 9-2

2. 2 s; 69 ft; 5 < b < 69
   Lesso n Ch eck


3. 
   

pp. 553-558

b. Answers may vary.

Sample: It is easy to

evaluate a quadratic

function in the form

y = ax2 + bx + c when

x= 0.