(I know this is the pre-cal forum, but the calculus isn't my problem here ... it's the basics that are dogging me.)

In order to make a wiggle graph, I need to find where my slopes are zero. The formula of my derivative is:

So my question is, when g'(x) = 0, x = ?

I don't think I'm just supposed to plug random numbers in and hope to hit 0, but simplifying has only gotten me a little closer. I

*think* I can simplify to:

It would be a little easier to just start plugging numbers in, but I think I'm supposed to actually solve this one before moving on. I'm stuck - how do I know what x is when g'(x) = 0?