take the derivitive f'(x)=-4x^3+4x find where it equals 0 0=-4x(x^2-1) 0=-4x(x-1)(x+1) at x=-1, 0, 1
those are critical points put those on number line test points between to see if positive or negative f'(-2)=(+) f'(-0.5)=(-) f'(0.5)=(+) f'(2)=(-) see attachment remember the max is where the slope changes from positive to negative at -1 and 1 only
