NAME
atanh, atanhf, atanhl – inverse hyperbolic tangent functions
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. For a discussion of error due to roundoff, see math(3).
RETURN VALUES
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 is returned.
SEE ALSO
HISTORY
The atanh(), atanhf(), and atanhl() functions appeared in 4.3BSD, FreeBSD 2.0, and FreeBSD 10.0, respectively.