ACOSH(3) BSD Library Functions Manual ACOSH(3)
NAME
acosh, acoshf -- inverse hyperbolic cosine function
LIBRARY
Math Library (libm, -lm)
SYNOPSIS
#include <math.h>
double
acosh(double x);
float
acoshf(float x);
DESCRIPTION
The acosh() and acoshf() functions compute the inverse hyperbolic cosine of the real argument x.
RETURN VALUES
If x is less than one, acosh(x) and acoshf(x) return NaN and set the global variable errno to EDOM.
SEE ALSO
asinh(3), atanh(3), exp(3), math(3)
HISTORY
The acosh() function appeared in 4.3BSD.
BSD
May 6, 1991 BSD
