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.
STANDARDS
The atanh() function conforms to ISO/IEC 9899:1999 (“ISO C99”).
HISTORY
The atanh() function appeared in 4.3BSD.