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.
HISTORY
The acosh() function appeared in 4.3BSD.
STANDARDS
The acosh() function conforms to ISO/IEC 9899:1999 (“ISO C99”).