DragonFly On-Line Manual Pages
ACOSH(3) DragonFly Library Functions Manual ACOSH(3)
NAME
acosh, acoshf -- inverse hyperbolic cosine functions
LIBRARY
Math Library (libm, -lm)
SYNOPSIS
#include <math.h>
double
acosh(double x);
float
acoshf(float x);
DESCRIPTION
The acosh() and the acoshf() functions compute the inverse hyperbolic
cosine of the real argument x. For a discussion of error due to round-
off, see math(3).
RETURN VALUES
The acosh() and the acoshf() functions return the inverse hyperbolic
cosine of x. If the argument is less than 1, acosh() raises an invalid
exception and returns an NaN.
SEE ALSO
asinh(3), atanh(3), exp(3), fenv(3), math(3)
HISTORY
The acosh() function appeared in 4.3BSD.
DragonFly 3.5 January 14, 2005 DragonFly 3.5