Which equation is y=9x^2+9x-1 re-written in vertex form

Question

asked Jul 8, 2020 217k views

2 Answers

Crosenblum · Answer 1 · 2020-07-10T09:51:34+0000

Answer:

A. y = 9(x +1/2)^2 - 13/4.

Explanation:

y = 9x^2 + 9x - 1

y = 9(x^2 + x) - 1

y = 9 [ (x + 1/2)^2 - 1/4] - 1

y = 9 (x + 1/2)^2 - 9/4 - 1

y = 9(x +1/2)^2 - 13/4.

Rudivonstaden · Answer 2 · 2020-07-14T21:56:53+0000

Answer: First Option

y = (x+(1)/(2)) ^ 2 -(13)/(4)[

Explanation:

For a quadratic function of the form:

y = ax ^ 2 + bx + c

The vertex form of the equation is:

y = (x-h) ^ 2 + k

Where the vertex is the point (h, k) and
h =-(b)/(2a)

In this case the equation is:
y=9x^2+9x-1

So:

$a=9\\b=9\\c=-1$

Therefore:

h =-(9)/(2*(9))

h =-(1)/(2)

$k=9(-(1)/(2))^2+9(-(1)/(2))-1\\\\k=-(13)/(4)$

Finally the equation in vertex form is:

y = (x+(1)/(2)) ^ 2 -(13)/(4)[