Primitive of Hyperbolic Tangent of a x over x

Theorem
where $B_k$ denotes the $k$th Bernoulli number.

Also see

 * Primitive of $\dfrac {\sinh a x} x$


 * Primitive of $\dfrac {\cosh a x} x$


 * Primitive of $\dfrac {\coth a x} x$


 * Primitive of $\dfrac {\sech a x} x$


 * Primitive of $\dfrac {\csch a x} x$