解析:
∫(1+tan²x)dx
=tanx+C
=∫x/(e^x-1)3d(e^x-1)=-1/2∫xd(1/(e^x-1)2)=-x/2(e^x-1)2+1/2∫1/(e^x-1)2dx=-x/2(e^x-1)2+1/2∫e^(-x)/(1-e^(-x))2d(1-e^(-x))=-x/2(e^x-1)2-1/2∫e^(-x)d(1/(1-e^(-x)))=-x/2(e^x-1)2-1/2(e^x-1)+1/2∫1/(1-e^(-x))de^(-x)=-x/2(e^x-1)2-1/2(e^x-1)-1/2ln|1-e^(-x)|+C