atanh
(PHP 4 >= 4.1.0, 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: This function is not
implemented on Windows platforms.
See also:
atan(),
asinh(), and
acosh().