y=x²(2-x) y' = 4x-3x^2=0x(3x-4)=0x=0 or 4/3f''(x) = 4-6xf''(0)= 4> 0 (min)f''(4/3)< 0 (max)max y =y(4/3)=(16/9)(2-4/3) =(16/9)(2/3)=32/27 local min y = y(0) =0lim(x->无穷）y = -无穷