acosh(3)

NAME

acosh, acoshf, acoshl — inverse hyperbolic cosine functions

SYNOPSIS

Math Library (libm, -lm)
#include <math.h>

double
acosh(double x);

float
acoshf(float x);

long double
acoshl(long double x);

DESCRIPTION

The acosh() function computes the inverse hyperbolic cosine of the real argument x. The acoshf() function is a single precision version of acosh(). The acoshl() function is an extended precision version of acosh().

RETURN VALUES

If x is less than one, acosh(x), acoshf(x) and acoshl(x) return NaN and set the global variable errno to EDOM.

SEE ALSO

asinh(3), atanh(3), exp(3)

HISTORY

The acosh() function appeared in 4.3BSD.