Answer:
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).
