f(x)=2x^3+3x^2-2x+10
f'(x)=6x^2+6x-2
令f'(x)=0
6x^2+6x-2=0
x1=(-3+√21)/6
x2=(-3-√21)/6
f’’(x)=12x+6
f’’(x1)>0f(x1)= 9.71788723 极小值
f’’(x2)