X-intercepts at (-2,0) and 2,0) with a maximum at (0,8)

Looking at the equation governing this curve:

If - 2 is one root, then (x+2) is one factor; if 2 is another root, then (x-2) is another factor.

The equation is then f (x) = a (x-2) (x+2), or f (x) = a (x^2 - 4).

When x=0, f (x) = 8. In other words, the vertex is at (0,8).

We must find the value of a in f (x) = a (x^2-4) : 8 = a (0^2) + 4. Then 8 = 4a, and a = 2.

Thus, the equation of this parabola is f (x) = 2 (x^2-4). Graph this and see for yourself whether the graph goes through (0,8), (-2,0) and (2,0).