设函数f(x)=-1/3x^3+2ax^2-3(a^2)x+b,0

问题描述:

设函数f(x)=-1/3x^3+2ax^2-3(a^2)x+b,0

f'(x)=-x^2+4ax-3a^2=-(x-a)(x-3a)
又0