What’s the vertex of this problem

the vertex of this parabolic graph is at (-4, -16).

Step-by-step explanation:

We are given f(x) = x^2 + 8x, and need to rewrite this in the form

                      f(x) = (x + 4)^2 + k, where the vertex is at (-4, k).

Complete the square:

                      f(x) = x^2 + 8x becomes   f(x) = x^2 + 8x + (4)^2 - (4)^2, or

                      f(x) = (x + 4)^2 - 16

Comparing this to:

                        f(x) = (x + 4)^2 + k

tells us that h = -4 and k = -16.

Thus, the vertex of this parabolic graph is at (-4, -16).

7.3

step-by-step explanation: