acosh

ACOSH(3)                   Linux Programmer's Manual                  ACOSH(3)



NAME
       acosh, acoshf, acoshl - inverse hyperbolic cosine function

SYNOPSIS
       #include <math.h>

       double acosh(double x);

       float acoshf(float x);

       long double acoshl(long double x);

DESCRIPTION
       The  acosh()  function  calculates  the inverse hyperbolic cosine of x;
       that is the value whose hyperbolic cosine is x.  If x is less 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), atanh(3), cosh(3), sinh(3), tanh(3)



                                  2002-07-25                          ACOSH(3)