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.