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

1 Answer

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

-b/(2a)

to give you the line of symmetry. So

-8/(2 * 2)=-2

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

y=2(-2)^2+8(-2)-3

This comes out to a value of

y = 8 - 16 - 3

y=-11

So the vertex will be (-2,-11).

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