public static double tanh (double x)

Returns the hyperbolic tangent of a ` double`

value.
The hyperbolic tangent of *x* is defined to be
(*e ^{x} - e^{-x}*)/(

Special cases:

- If the argument is NaN, then the result is NaN.
- If the argument is zero, then the result is a zero with the same sign as the argument.
- If the argument is positive infinity, then the result is
`+1.0`

. - If the argument is negative infinity, then the result is
`-1.0`

.

The computed result must be within 2.5 ulps of the exact result.
The result of ` tanh`

for any finite input must have
an absolute value less than or equal to 1. Note that once the
exact result of tanh is within 1/2 of an ulp of the limit value
of ±1, correctly signed ±` 1.0`

should
be returned.

`x` | The number whose hyperbolic tangent is to be returned. |

` x`

.

Diagram: Math