f(x)=(2x-1)^2(x^2-9)
find f'(x)=0
So first derivative:
f'(x)=16x^3-6x^2-70x+36
0 = 16x^3-6x^2-70x+36
Ok.. I know I should factor it somewhere.. I just couldn't see where..
Thanks!
f'(x) should read:
16x^3-12x^2-70x+36
and f'(-2)=0
From there, you can find the other factors.
