设x=1/cost t=arc cos(1/x)dx=(sint/cos²t)dtx*√(x²-1)=(1/cost)*sint/cost=sint/cos²t所以∫[(1)/(x√(x^(2)-1))]dx =∫(sint/cos²t)*/(sint/cos²t)*dt=∫dt=t=arc cos(1/x) I(2,√2)=ar...