∫(secx)^2dx/√(tanx+1)
=∫dtanx/√(tanx+1)
=2√(tanx+1)+C
回复∫dtanx/√(tanx+1) 原式=∫du/√u=∫u^(-1/2)du=1/(1/2)∫du^(1/2)=2u=2√(tanx+1)