# How do you find the vertex of y=x^2 - 5x + 4?

$\left(\frac{5}{2} , \frac{- 9}{4}\right)$
$\frac{- b}{2 a}$ gives the x coord of the vertex
$\implies \frac{- - 5}{2} = 2 \frac{1}{2}$
When $x = 2 \frac{1}{2} , y = \frac{25}{4} - \frac{25}{2} + 4 = \frac{- 9}{4}$