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。