Use the form , to find the values of , , and .

Consider the vertex form of a parabola.

Substitute the values of and into the formula .

Cancel the common factor of and .

Factor out of .

Move the negative one from the denominator of .

Multiply by .

Simplify each term.

Cancel the common factor of and .

Factor out of .

Move the negative one from the denominator of .

Multiply by .

Multiply by .

Add and .

Substitute the values of , , and into the vertex form .

Complete the Square -x^2+4x-8