# What is the axis of symmetry and vertex for the graph y = –3(x + 8)^2 + 5?

Apr 13, 2018

$x = - 8 , \text{ vertex } = \left(- 8 , 5\right)$

#### Explanation:

$\text{the equation of a parabola in "color(blue)"vertex form}$ is.

$\textcolor{red}{\overline{\underline{| \textcolor{w h i t e}{\frac{2}{2}} \textcolor{b l a c k}{y = a {\left(x - h\right)}^{2} + k} \textcolor{w h i t e}{\frac{2}{2}} |}}}$

$\text{where "(h,k)" are the coordinates of the vertex and a}$
$\text{is a multiplier}$

$y = - 3 {\left(x + 8\right)}^{2} + 5 \text{ is in vertex form}$

$\text{with } \left(h , k\right) = \left(- 8 , 5\right)$

$\Rightarrow \textcolor{m a \ge n t a}{\text{vertex }} = \left(- 8 , 5\right)$

$\text{since "(x+8)^2" then graph opens vertically}$

$\text{the axis of symmetry passes through the vertex}$

$\text{with equation } x = - 8$