NAME
acosh, acoshf,
acoshl —
inverse hyperbolic cosine
functions
SYNOPSIS
#include
<math.h>
double
acosh(double
x);
float
acoshf(float
x);
long double
acoshl(long
double 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().
The
acoshl()
function is an extended precision version of
acosh().
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.
SEE ALSO
HISTORY
The acosh() function appeared in
4.3BSD.