atanh
(PHP 4 >= 4.0.7, PHP 5)
atanh — Inverse hyperbolic tangent
Description
    float atanh
     ( float $arg
    )
  Returns the inverse hyperbolic tangent of arg , i.e. the value whose hyperbolic tangent is arg .
Note: Tätä funktiota ei ole vielä implementoitu Windows-alustalle.
Parameters
- arg
- 
      The argument to process 
Return values
Inverse hyperbolic tangent of arg