Question

Find the vertex for the following functions.

f(x) = -2x2 + 8x + 3
A. (11,2)
B.(2,11)
C.(0,0)

Answer 1

Vertex is (2, 11)

Explanation:

Call the vertex (h, k)

A quick way to find h is use the formula h = -b/2a

In your case, h = -8/-4 = 2

Now, to find k.

k = f(2) = -2(2)^2 +8(2) + 3

= -8 + 16 + 3

= 11

Vertex is (2, 11)