Primitive of Hyperbolic Tangent of a x

Theorem

 * $\displaystyle \int \tanh a x \ \mathrm d x = \frac {\ln \left\vert{\cosh a x}\right\vert} a + C$

Also see

 * Primitive of $\sinh a x$
 * Primitive of $\cosh a x$
 * Primitive of $\coth a x$
 * Primitive of $\operatorname{sech} a x$
 * Primitive of $\operatorname{csch} a x$