Primitive of Hyperbolic Tangent of a x

Theorem

 * $\ds \int \tanh a x \rd x = \frac {\ln \size {\cosh a x} } a + C$

Also see

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