ATANH(3) | Library Functions Manual | ATANH(3)

# NAME

`atanh`, `atanhf`, `atanhl` —
inverse hyperbolic tangent function

# LIBRARY

Math Library (libm, -lm)

# SYNOPSIS

`#include <math.h>`

double
`atanh`(double x);

float
`atanhf`(float x);

long double
`atanhl`(long double x);

# DESCRIPTION

The `atanh`(), `atanhf`(), and `atanhl`() functions compute the inverse hyperbolic tangent of the real argument x.

# RETURN VALUES

If |x|≥1, `atanh`(x), `atanhf`(x), and `atanhl`(x) return +inf, -inf or NaN, and sets the global variable errno to EDOM.

# SEE ALSO

acosh(3), asinh(3), exp(3), math(3)

# STANDARDS

The `atanh`() function conforms to ISO/IEC 9899:1999 (“ISO C99”).

# HISTORY

The `atanh`() function appeared in 4.3BSD.

January 29, 2013 | NetBSD 9.5