acosh(3) BSD Library Functions Manual acosh(3)
NAME
acosh -- inverse hyperbolic cosine function
SYNOPSIS
#include <math.h>
double
acosh(double x);
long double
acoshl(long double x);
float
acoshf(float x);
DESCRIPTION
The acosh() function computes the principle value of the inverse hyper-
bolic cosine of x. The result is in the range [0, +infinity].
SPECIAL VALUES
acosh(1) returns +0.
acosh(x) returns a NAN and raises the "invalid" floating-point exception
for x < 1.
acosh(+infinity) returns +infinity.
SEE ALSO
asinh(3), atanh(3), exp(3), math(3)
STANDARDS
The acosh() function conforms to ISO/IEC 9899:1999(E).
HISTORY
The acosh() and acoshf() function appeared in 4.3BSD.
4.3 Berkeley Distribution December 11, 2006 4.3 Berkeley Distribution
Mac OS X 10.6 - Generated Thu Sep 17 20:18:21 CDT 2009