解题关键:第二类换元积分法。
满意请采纳!!!
∫dx/x√(x^2-1)=1/2∫dx^2/x^2√(x^2-1)= 1/2∫dt/t√(t-1) (令x^2=t)
=1/2∫2udu/(u^2+1)u (令√(t-1) =u,t=u^2+1)
=∫du/(u^2+1)
=actanu+C
=actan√(x^2-1)+C