Review 2/3, 4, 6A, 7
1. Find the zeros of each function by using the table feature of the graphing calculator.
a. f(x) = x2 + 5x + 6
b. g(x) = x2 – 4x – 5
2
c. f(x) = x – 7x + 12
d. g(x) = x2 + 3x - 10
2. Find the roots of each equation by factoring.
a. 16x2 = 9
c. x2 + 9x + 20
b. 2x2 + 4 = -9x
d. x2 – 5x – 50 = 0
3. Solve each equation by completing the square. Leave answers as simplified radicals.
a. x2 – 6x – 23 = 0
b. x2 + 13 = -14x
c. 2x2 – 8x – 7 = 0
d. 3x2 + 18x = 10
4. Find the zeros of each function by using the Quadratic Formula. Leave answers as simplified radicals.
a. f(x) = x2 + 10x + 9
b. f(x) = 2x2 + 5x – 3
2
c. f(x) = x – 8x – 12
d. f(x) = 3x2 + 9x + 2
5. Write each function in vertex form, then identify its vertex.
a. f(x) = x2 – 6x – 2
b. f(x) = 3x2 – 6x – 15
c. f(x) = x2 + 4x + 9
d. f(x) = 2x2 + 8x – 9
Answers:
1.
2.
3.
4.
5.
a.
a.
a.
a.
a.
x = -2 or -3
x=±¾
x=3±4 2
x = -1 or -9
(3, -11)
b.
b.
b.
b.
b.
x = -1 or 5
x = ½ or -4
x = -1 or -13
x = -3 or ½
(1, -18)
c.
c.
c.
c.
c.
x = 3 or 4
x = -5 or -4
x = 2 ± ½ 30
x=4±2 7
(-2, 5)
d.
d.
d.
d.
d.
x = -5 or 2
x = -5 or 10
x = -3 ± 111 /3
x = -3/2 ± 57 /6
(-2, -17)