Question

This graph represents a quadratic function. What is the function's equation written in factored form and in vertex form?

(graph in picture)

Answer 1

Explanation:

f(x) = a(x-x1) (x-x2)

from the vertex, we get a:

0 = a(4-2)²- 8

4a = 8

a = 2

so, the equation:

f(x) = 2(x-0) (x-4)

f(x) = 2x(x-4)

f(x) = 2x² -8x