函数f(x)在x=-1处的斜率为-3f'(-1)=3(-1)²+2a(-1)=-3,解得a=3点p(-1,b)在曲线上(-1)³+3(-1)²=b,b=2P(-1,2)在所求直线上设所求直线为3x+y+c=0,则3(-1)+2+c=0,c=1求得直线方程为:3x+y+1=0...