S sec Udu = In/secu + tanUltc sec'x dx Let V = Sec x d v = sec x tan x dx du = sec - x dx V z tanx = S sec 3 x dx = Sec x tan x = Ssec x tan xox = Jsec 3 x dx = Secx tank =Jsecx (sec" x-1 ) dx = sec x tan x - Ssec 3 x dx + Ssec x dx = 2S sec " x dx = secx tan x+ In/ secx +tank) S sec " x dx = = ( see x tan x + in/ sccx + tan * 1 ) +C