y'=3x²+6x+6=3x²+6x+3+3=3(x²+2x+1)+3=3(x+1)²+3平方项恒非负,(x+1)²≥0 (x+1)²+3≥3,当x=-1时,y'有最小值3x=-1代入曲线方程：y=(-1)³+3(-1)²+6(-1)-10=-1+3-6-10=-14切线...