1.曲线y=x^3+11在点P(1,12)处的切线与y轴交点的纵坐标是?2

问题描述:

1.曲线y=x^3+11在点P(1,12)处的切线与y轴交点的纵坐标是?2
1.曲线y=x^3+11在点P(1,12)处的切线与y轴交点的纵坐标是?
2.已知函数f(x)=ax^2+3x-2在点(2,f(2))处的切线斜率为7,则实数a为?

1.对方程求导 y'=3x^2,x=1处的导数就是3*1^2=3
所以切线是y-12=3(x-1),x=0带入y=9
2.求导得f'(x)=2ax+3 x=2带入,2a*2+3=7,a=1