now,apply integration by parts,
I=secA*INT[sec^2AdA]-int.[secA*tan^2AdA]
=secA*tanA-int.(sec^3AdA)+log(secA+tanA)
so,2I=secA*tanA+log(secA+tanA)
I am not getting what you typed. Under the "now apply int. by parts" you did two separate int by parts there? I can't tell what that is. Can you tell me what you used for your substitutions u & dv?
Thanks!