ACOSH(3) |
Library Functions Manual |
ACOSH(3) |
NAME
acosh, acoshf, acoshl — inverse hyperbolic cosine function
LIBRARY
Math Library (libm, -lm)
SYNOPSIS
#include <math.h>
double
acosh(double x);
float
acoshf(float x);
long double
acoshl(long double x);
DESCRIPTION
The acosh(), acoshf(), and acoshl() functions compute the inverse hyperbolic cosine of the real argument x.
RETURN VALUES
If x is less than one, acosh(x), acoshf(x), and acoshl(x) return NaN and set the global variable errno to EDOM.
STANDARDS
The acosh() function conforms to ISO/IEC 9899:1999 (“ISO C99”).
HISTORY
The acosh() function appeared in 4.3BSD.