Help me look at a math problem, a difficult problem in junior high school. How to determine the maximum and minimum of cubic function? What is the following question?
f(x)=x^3- 12x+8，
f'(x)=3x^2- 12=0，
X= soil 2.
f(-2)=24，
f(2)=-8，
f(-3)= 17，
f(3)=- 1，
Therefore, its maximum value M=24 and minimum value m=-8 are in the interval [-3,3].
M-m=32。