ATANH(3) Library Functions Manual ATANH(3)

NAME

atanh, atanhf, atanhlinverse 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)

HISTORY

The atanh() function appeared in 4.3BSD.

STANDARDS

The atanh() function conforms to ISO/IEC 9899:1999 (“ISO C99”).
January 29, 2013 NetBSD 6.99