Primitive of Square of Hyperbolic Cosine of a x over Hyperbolic Sine of a x

Theorem

 * $\displaystyle \int \frac {\cosh^2 a x \ \mathrm d x} {\sinh a x} = \frac {\cosh a x} a + \frac 1 a \ln \left\vert{\tanh \frac {a x} 2}\right\vert + C$