# What is the vertex of y= 2x^2 + 8x − 3?

May 8, 2018

You can find the line of symmetry, and then plug in to find the $y$ point that correlates to this line.

#### Explanation:

To do this, use

$- \frac{b}{2 a}$

to give you the line of symmetry. So

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

Now, you can plug this back into the original so you will receive

$y = 2 {\left(- 2\right)}^{2} + 8 \left(- 2\right) - 3$

This comes out to a value of

$y = 8 - 16 - 3$

$y = - 11$

So the vertex will be $\left(- 2 , - 11\right)$.

graph{2x^2 + 8x -3 [-5, 5, -15, 5]}