* The hyperbolic arc-tangent of a number is the inverse of the TANH function.
* This function is also called the inverse hyperbolic tangent function.
* If "number" > 1, then #NUM! is returned.
* If "number" < 1, then #NUM! is returned.
* If "number" = 1, then #NUM! is returned.
* If "number" is not numeric, then #VALUE! is returned.
* You can use the ACOSH function to return the hyperbolic arc-cosine.
* You can use the ASINH function to return the hyperbolic arc-sine.
* You can use the TANH function to return the hyperbolic tangent.
* For a working example refer to the Hyperbolic Functions page.
* For the Microsoft documentation refer to support.office.com