f(x)=x^{2}+2x-4 Interval is [-1, 1]

What I did:

f'(x)=2x+2

x=-1

Plugged in:

One of my minimums is (-1, 0)

I'm confused on how to get the maximum now.

I did 0=x^{2}+2x-4

4=x(x+2)

4/(x+2)=x

But I don't think this is correct.

Please explain.

Thanks!