How do you evaluate the integral int sec^2x/(1+tanx)dxsec2x1+tanxdx?

1 Answer
Jan 2, 2017

intsec^2x/(1 + tanx)dx = ln|1 + tanx| + Csec2x1+tanxdx=ln|1+tanx|+C

Explanation:

This is a u-subsitution problem. Our goal is to cancel out the numerator. Let u = 1 + tanxu=1+tanx. Then du = sec^2xdxdu=sec2xdx and dx= (du)/sec^2xdx=dusec2x

=intsec^2x/u * (du)/sec^2x=sec2xudusec2x

= int(1/u) du=(1u)du

This can be integrated as int(1/x)dx = ln|x| + C(1x)dx=ln|x|+C.

= ln|u| + C=ln|u|+C

= ln|1 + tanx| + C=ln|1+tanx|+C, where CC is a constant

Hopefully this helps!