ATANH(3)                  OpenBSD Programmer's Manual                 ATANH(3)

NAME
     atanh, atanhf - inverse hyperbolic tangent functions



SYNOPSIS
     #include <math.h>

     double
     atanh(double x);

     float
     atanhf(float x);

DESCRIPTION
     The atanh() and atanhf() functions compute the inverse hyperbolic tangent
     of the real argument x.

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

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

HISTORY
     The atanh() function appeared in 4.3BSD.

OpenBSD 2.6                       May 6, 1991                                1