atanh, atanhf[inverse hyperbolic tangent]

f78 atanh, atanhf[inverse hyperbolic tangent]

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.