The critical numbers occur where this function's first derivative is equal to zero, or where it is undefined. Using the Power Rule and the Chain Rule, the derivative is:
f'(x) = (2x - 1)/(3x² - 3x)2/3
This will equal zero when the numerator equals 0, which is at x = 1/2
It will be undefined when the denominator equals 0.
3x² - 3x = 3x(x - 1) = 0
This occurs at x = 0 and x = 1