ACOSH(3)

NAME
acosh - inverse hyperbolic cosine function

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
Exceptional cases are handled by matherr(3).

SEE ALSO
asinh(3), atanh(3), exp(3), infnan(3), math(3), matherr(3)

HISTORY
The acosh() function appeared in 4.3BSD.