Question

Can someone please help me understand.

Answer 1

I need to find the vertex of the function f(x) = 5x2 + 10x + 8
Ive come up with the answer (-1,-3)

Answer 2

The multiple choice answers are
(1,8)
(-1,3)

Answer 3

-1 is ok, now plug back
\(5 (-1)^2 + 10 (-1) +8= 5 -10 +8 =3 \)

Answer 4

The way im learning how to find y is by converting this to quadratic equation form.
I converted f(x) = 5x2 + 10x + 8 to y - 8 = 5(x+1)^2 - 3

Answer 5

Did I do something wrong?

Answer 6

Oh i didnt mean to put the y - 8 there

Answer 7

You made it so complicated. if x=-1, just plug -1 into the original equation to find y. Dat sit.

Answer 8

Thanks :p