Which Equation Is Y = 9x2 + 9x 2013 1 Rewritten In Vertex Form?

Which equation is y = 9x2 + 9x – 1 rewritten in vertex form?

 

Answer:

y = 9(x + 1/2)² - 13/4

Step-by-step explanation:

Given:

y = 9x² + 9x - 1

a = 9

b = 9

c = -1

Vertex form:

y = a(x - h)² + k

Where:

(h, k) is the vertex

h = -b/2a

k = f(h)

Find the vertex:

h = -(9)/(2×9)

h = -9/18

h = -1/2

k = f(h)

f(h) = 9h² + 9h - 1

f(-1/2) = 9(-1/2)² + 9(-1/2) - 1

k = 9(1/4) - 9/2 = -1

k = 9/4 - 9/2- 1

LCD: 4

k = 9/4 - 18/4 - 4/4

k = 9/4 - 22/4

k = -13/4

Vertex Form:

y = a(x - h)² + k

y = 9(x - (-1/2))² + (-13/4)

y = 9(x + 1/2)² - 13/4