Question

Identify the vertex of the parabola. (EASY! 10 Points)

Answer 1

B

Explanation:

given a parabola in standard form

f(x) = ax² + bx + c (a ≠ 0 ) , then

the x-coordinate of the vertex is

`x_(vertex)` = -
`(b)/(2a)`

f(x) = - 4x² - 16x - 13 ← is in standard form

with a = - 4 , b = - 16 , then

`x_(vertex)` = -
`(-16)/(2(-4))` = -
`(-16)/(-8)` = - 2

substitute x = - 2 into f(x) for corresponding y- coordinate

f(- 2) = - 4(- 2)² - 16(- 2) - 13

= - 4(4) + 32 - 13

= - 16 + 19

= 3

vertex = (- 2, 3 )