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.