atanhl

ATANH(3)		  Linux Programmer’s Manual		     ATANH(3)



NAME
       atanh, atanhf, atanhl - inverse hyperbolic tangent function

SYNOPSIS
       #include <math.h>

       double atanh(double x);

       float atanhf(float x);

       long double atanhl(long double x);


DESCRIPTION
       The  atanh()  function calculates the inverse hyperbolic tangent of x;
       that is the value whose hyperbolic tangent  is  x.   If	the  absolute
       value of x is greater than 1.0, acosh() returns not-a-number (NaN) and
       errno is set.

ERRORS
       EDOM   x is out of range.

CONFORMING TO
       SVID 3, POSIX, BSD 4.3, ISO 9899.  The float and long double  variants
       are C99 requirements.

SEE ALSO
       asinh(3), acosh(3), cosh(3), sinh(3), tanh(3)



				  2002-07-27			     ATANH(3)