NAME    [Toc]    [Back]

     atanh, atanhf - inverse hyperbolic tangent functions

SYNOPSIS    [Toc]    [Back]

     #include <math.h>

     double
     atanh(double x);

     float
     atanhf(float x);

DESCRIPTION    [Toc]    [Back]

     The atanh() function computes the inverse hyperbolic tangent
of the real
     argument  x.   The  atanhf()  function is a single precision
version of
     atanh().

RETURN VALUES    [Toc]    [Back]

     If |x|>=1, atanh(x) and atanhf(x) return +inf, -inf or  NaN,
and set the
     global variable errno to EDOM.

SEE ALSO    [Toc]    [Back]

     acosh(3), asinh(3), exp(3), infnan(3), math(3)

HISTORY    [Toc]    [Back]

     The atanh() function appeared in 4.3BSD.

OpenBSD      3.6                            May      6,      1991