ACOSH(3) BSD 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 ALSOasinh(3), atanh(3), exp(3), fenv(3), math(3)HISTORY
The acosh() function appeared in 4.3BSD.
BSD January 14, 2005 BSD