Question

What is the vertex of the function f(x) = x2 + 12x?

(–6, –36)
(–6, 0)
(6, 0)
(6, –36)

Answer 1

A: (-6, -36)

Explanation:

This should be the right answer on edge,

please correct me if I'm wrong.

Answer 2

(- 6, - 36 )

Explanation:

Given a parabola in standard form

y = ax² + bx + c ( a ≠ 0 )

Then the x- coordinate of the vertex is

x = -
`(b)/(2a)`

f(x) = x² + 12x ← is in standard form

with a = 1, b = 12, c = 0 , then

x = -
`(12)/(2)` = - 6

Substitute x = - 6 into f(x) for corresponding value of y

f(- 6) = (- 6)² + 12(- 6) = 36 - 72 = - 36

vertex = (- 6, - 36 )