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

NAME
     acosh, acoshf - inverse hyperbolic cosine functions

SYNOPSIS
     #include <math.h>

     double
     acosh(double x);

     float
     acoshf(float x);

DESCRIPTION
     The acosh() function computes the inverse hyperbolic cosine of the real
     argument x.  The acoshf() function is a single precision version of
     acosh().

RETURN VALUES
     If x is less than one, acosh(x) and acoshf(x) return NaN and set the
     global variable errno to EDOM.

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

HISTORY
     The acosh() function appeared in 4.3BSD.

OpenBSD 4.0                       May 6, 1991                                1
