NAME
atanh, atanhf,
atanhl —
inverse hyperbolic tangent
function
LIBRARY
library “libm”
SYNOPSIS
#include
<math.h>
double
atanh(double
x);
float
atanhf(float
x);
long double
atanhl(long
double x);
DESCRIPTION
Theatanh(),
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
STANDARDS
The atanh() function conforms to
ISO/IEC 9899:1999
(“ISO C99”).
HISTORY
The atanh() function appeared in
4.3BSD.