材料88级每tm-0026m-f是碳素钢
f'(x)=2mx-2 k=f'(0)=-2 y-m=-2x 2x+y-m=0 x^2+y^2-4x-2y=0 (x-2)^2+(y-1)^2=5 |4+1-m|=5 m-5=5或-5 m=10或0 (2)mx^2-2x+m<=0 M={x|(2-√(1-m^2))/m<x<(2+√(1-m^2))/m}