x=sect,则∫dx/[x+√(x^2-1)]=∫sect*tantdt/(sect+tant)=∫sect*tant(sect-tant)dt=∫[(sect)^2tant-sect(tant)^2]dt=∫tantd(tant)-∫(sect)^3dt+∫sectdt=(1/2)(tant)^2+ln│sect+tant│-∫(sect)^3dt计算∫(sect...