atanh,
atanhf
[inverse hyperbolic
tangent]
SYNOPSIS
#include <math.h> double atanh(double x); float atanhf(float x);
DESCRIPTION
atanh
calculates the inverse hyperbolic tangent
of x.
atanhf is identical, other than taking and returning float values.
RETURNS
atanh
and atanhf
return the calculated value.
If x
is greater than 1, the global errno
is set to EDOM
and the result is a NaN.
A DOMAIN
error
is reported.
Ifx
is 1, the global errno
is set to EDOM;
and the result is infinity with the same sign as x.
A SING
error
is reported.
You can modify the error handling for these routines using matherr.
COMPLIANCE
Neither atanh
nor atanhf
are ANSI C.