What is the antiderivative of tanxdx?

1 Answer
Oct 7, 2015

The antiderivative of tan(x) is ln(cos(x))

Explanation:

We know tan(x)=sin(x)cos(x).

tan(x)dx=sin(x)cos(x)dx

We can use substitution to simplify the integral.

u=cos(x) and du=sin(x)dx

tan(x)dx=sin(x)cos(x)dx=1udu=ln(u)+C

To get the answer, just plug u back in to get:

ln(cos(x))