====== Description ======
The cosh node returns the hyperbolic cosine of the value of its child-node.

====== Constraints ======
  * Minimum number of child-nodes: 1
  * Maximum number of child-nodes: 1
  * Valid input range: no constraints, but must be in radians

====== Calculus ======
The cosh node returns the hyperbolic cosine of the angle (in radians) represented by its child-node's value.

value = e<sup>x</sup> + e<sup>-x</sup>, where x = value<sub>1</sub>