ACOSH(3) BSD Library Functions Manual ACOSH(3)NAME
acosh — inverse hyperbolic cosine function
SYNOPSIS
#include <math.h>
double
acosh(double x);
DESCRIPTION
The acosh() function computes the inverse hyperbolic cosine of the real
argument x.
SPECIAL VALUESacosh(1) returns +0.
acosh(x) returns a NAN and raises the "invalid" floating-point exception
for x < 1.
acosh(+infinity) returns +infinity.
SEE ALSOasinh(3), atanh(3), exp(3), infnan(3), math(3), matherr(3)STANDARDS
The acosh() function conforms to ISO/IEC 9899:1999(E).
HISTORY
The acosh() function appeared in 4.3BSD.
4.3 Berkeley Distribution November 15, 2002 4.3 Berkeley Distribution