# How do you write the vertex form equation of the parabola #y = -2(x+4)(x-2)#?

##### 1 Answer

Please see the explanation.

#### Explanation:

Given:

Multiply the factors:

Please observe that equation [1] is in the standard form

The vertex form of a parabola of this type is:

The "a" in the standard form and the "a" in the vertex form are the same attribute of the parabola, therefore, substitute -2 for "a" into equation [2]:

We know that

Substitute -1 for h into equation [3]:

Evaluate equation [1] at

Evaluate equation [4] and x = 0 and y = 16, then solve for k:

The vertex form is: