问题
填空题
设m∈R,已知函数f(x)=-x2-2mx2+(1-2m)x+3m-2,若曲线y=f(x)在x=0处的切线恒过定点P,则点P的坐标为______.
答案
f(x)=-x3-2mx2+(1-2m)x+3m-2,f′(x)=-3x2-4mx+(1-2m).
因为f(0)=3m-2,f′(0)=1-2m,
所以曲线y=f(x)在x=0处的切线方程为y-(3m-2)=(1-2m)(x-0),
即m(2x-3)+(y-x+2)=0.
由于
得2x-3=0 y-x+2=0 x= 3 2 y=- 1 2
故切线恒过定点P(
,-3 2
)1 2
故答案为:(
,-3 2
).1 2