Question

Find the vertex of the quadratic equation: y = 2x2 + 8x − 4

Answer 1

Do you know how to find the x coordinate of the vertex?

Answer 2

i dont think

Answer 3

If you have the general equation

\[\Large ax^2+bx+c=0\]

then the x coordinate of that vertex is

\[\Large x = -\frac{b}{2a}\]

Answer 4

In the case of \(\Large y = 2x^2+8x-4\), we can see that a = 2, b = 8 and c = -4

Answer 5

Does that help?

Answer 6

yeah kinda

Answer 7

So what do you get for the x coordinate of the vertex?

Answer 8

i got -2

Answer 9

good

Answer 10

Since x = -2 is the x coordinate of the vertex, you can find the y coordinate of the vertex by plugging in this x value.

So...

\(\Large y = 2x^2+8x-4\)

\(\Large y = 2(-2)^2+8(-2)-4\)


I'll let you finish

Answer 11

okay i got (-2,-12)

Answer 12

you nailed it

Answer 13

thank you for your help

Answer 14

you're welcome