Quadratic function - x-intercepts?

[Agent_J]

f(x) = -2x^2 + 12x + 12

I was able to express it in standard form and find the maximum value, but I can't seem to get the x-intercepts

I got -2x^2 + 12x + 12 = 0
-2 (x^2 - 6x + 6) = 0

does that mean I need to use the quadratic formula or did I do something wrong?

 

[Zurtex]

There is a Homework help zone. But you have:

-2 (x^2 - 6x + 6) = 0

If a product equals 0 at least one of the bits of the product must equal 0. So either:

-2 = 0

or:

x^2 - 6x + 6 = 0

I think we can safely assume that -2 does not equal 0. So now you can solve:

x^2 - 6x + 6 = 0

By using the quadratic equation or completing the square (although it would have been just as easy to use the quadratic equation on -2x^2 + 12x + 12) I'm fairly sure this does not factorise.