sec cube dx
Do you want the integral of sec^3 x?
That would be
(1/2)secx*tanx + (1/2)log|secx +tanx|
For a derivation, see
http://en.wikipedia.org/wiki/Integral_of_secant_cubed
That would be
(1/2)secx*tanx + (1/2)log|secx +tanx|
For a derivation, see
http://en.wikipedia.org/wiki/Integral_of_secant_cubed