Primitive of Product of Hyperbolic Cosecant and Cotangent

Theorem

 * $\displaystyle \int \csch x \coth x \rd x = -\csch x + C$

where $C$ is an arbitrary constant.

Proof
From Derivative of Hyperbolic Cosecant:
 * $\dfrac \d {\d x} \csch x = -\csch x \coth x$

The result follows from the definition of primitive.