# How do I use the vertex formula to determine the vertex of the graph for  y = x^2-6x+8?

May 20, 2018

(3,-1)

#### Explanation:

use $- \frac{b}{2 a}$ to find the x-value
a = 1 because the first term is ${x}^{2}$
b = -6 because the second term is -6x

$- \frac{- 6}{2 \cdot 1}$

x=3

plug it back in to the original equation
${\left(3\right)}^{2} - 6 \left(3\right) + 8$

=-1
the vertex is (3,-1)