f(x)=1/(x-2)-1/(x-1)故f'(x)=-1/(x-2)^2+1/(x-1)^2f(2)(x)=2*1/(x-2)^3-2*1/(x-1)^3……f(n)(x)=n!*(-1)(n)*1/(x-2)^(n+1)-n!*(-1)(n)*1/(x-1)^(n+1)希望你看得明白,百度的数学输入真是有待提高....