ACOSH

Section: Linux Programmer's Manual (3)
Updated: June 13, 1993
 

NAME

acosh - inverse hyperbolic cosine function  

SYNOPSIS

#include <math.h>

double acosh(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  

SEE ALSO

asinh(3), atanh(3), cosh(3), sinh(3), tanh(3)