The
atanh ();
and the
atanhf ();
functions compute the inverse hyperbolic tangent
of the real
argument
x
For a discussion of error due to roundoff, see
math(3).
RETURN VALUES
The
atanh ();
and the
atanhf ();
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.
