Consider the quadratic function:

f(x) = x2 – 8x – 9

vertex:

what is the vertex of the function?

(4, - 25)

Step-by-step explanation:

Given a quadratic in standard form : ax² + bx + c : a ≠ 0

Then the x- coordinate of the vertex is

= -

f(x) = x² - 8x - 9 is in standard form

with a = 1, b = - 8 and c = - 9, thus

= - = 4

Substitute x = 4 into f(x) for corresponding y- coordinate

f(4) = 4² - 8(4) - 9 = 16 - 32 - 9 = - 25

Vertex = (4, - 25)

no, because the sides are not congruent

the correct answers i think are b. and d.

give me brainliest if it is correct!