∫sec^5dx=?

∫ sec^2 x dx ∫(tan^(5)(x)*sec^(4)(x))dx ∫[(sec^2x-1)secx]dx= ∫secx/sec^2x-1 dx 不定积分∫sec^4 x dx ∫（sec^2x+sinx)dx ∫sec²x/1+tanx dx =∫dx/(2cos^2(x/2)+1)=∫sec^(x/2)dx/(2+sec^2(x/2))怎么出来的? ∫sec^4x dx ∫sec^2x tan^2x dx ∫secxdx =∫secx(secx+tanx)dx//(secx+tanx) =∫(sec&# ∫tan^2xdx=∫(sec^2x-1)dx sec^2 x是f(x)的一个原函数,则∫xf'(x)dx=?