∫(secx)ntanxdx is equal to
−(secx)n+1n+1+C
(secx)n+1n+1+C
(secx)nn+C
−1n(secx)n+C
Let I=∫(secx)ntanxdx
I=∫(secx)n−1(secxtanx)dx
Let secx=t
secxtanxdx=dtI=∫tn−1dt=tnn+C=(secx)nn+C