# How do you find the axis of symmetry, graph and find the maximum or minimum value of the function y=x^2+8x-1?

Jun 26, 2018

$x = - 4$ is the axis of symmetry
Minimum at (-4,-17)

#### Explanation:

$\frac{- b}{2 a}$ gives the axis of symmetry

$- \frac{8}{2} = - 4$

$y = {\left(- 4\right)}^{2} + 8 \times - 4 - 1$

$y = - 17$

To graph the function you can draw a table of results knowing there is symmetry about $x = - 4$