Manual Pages  — ATANH

atanh, atanhf, atanhl – inverse hyperbolic tangent functions

LIBRARY SYNOPSIS DESCRIPTION RETURN VALUES SEE ALSO HISTORY

Math Library (libm, -lm)

#include <math.h>

double
atanh(double x);

float
atanhf(float x);

long double
atanhl(long double x);

These functions return the inverse hyperbolic tangent of x if successful. If the argument has absolute value 1, a divide-by-zero exception is raised and an infinity is returned. If |x| > 1, an invalid exception is raised and an NaN is returned.

The atanh(), atanhf(), and atanhl() functions appeared in BSD 4.3, FreeBSD 2.0, and FreeBSD 10.0, respectively.