Return hyperbolic tangent of a number

Contract
Return type	wob
No input parameters.

Water Contract
<method number.double.tanh/>

See also: cos, acos, cosh, sin, asin, sinh, tan, atan, atan2, radians_to_degrees, degrees_to_radians, double

Returns the hyperbolic tangent of a _subject of type double .

1.0.<tanh />

0.7615941559557649