Determine where the absolute extrema of f(x)=3x^2/3-2x on the interval [-1,1] …

Determine where the absolute extrema of f(x)=3x232xf(x)=3x^{\frac{2}{3}}-2x on the interval [1,1] [-1,1] occur, and their values.
More Maximum and Minimum on Closed Intervals Questions: