ACOSH(3) Library Functions Manual ACOSH(3)

NAME

acosh, acoshf, acoshlinverse hyperbolic cosine function

LIBRARY

Math Library (libm, -lm)

SYNOPSIS

#include <math.h>

double
acosh(double x);

float
acoshf(float x);

long double
acoshl(long double x);

DESCRIPTION

The acosh(), acoshf(), and acoshl() functions compute the inverse hyperbolic cosine of the real argument x.

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), math(3)

HISTORY

The acosh() function appeared in 4.3BSD.

STANDARDS

The acosh() function conforms to ISO/IEC 9899:1999 (“ISO C99”).
January 29, 2013 NetBSD 6.99