DragonFly On-Line Manual Pages


ACOSH(3)	      DragonFly Library Functions Manual	      ACOSH(3)

NAME

acosh, acoshf, acoshl -- inverse hyperbolic cosine functions

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 hyper- bolic cosine of the real argument x. For a discussion of error due to roundoff, see math(3).

RETURN VALUES

These functions return the inverse hyperbolic cosine of x. If the argu- ment is less than 1, acosh() raises an invalid exception and returns an NaN.

SEE ALSO

asinh(3), atanh(3), exp(3), fenv(3), math(3)

HISTORY

The acosh(), acoshf(), and acoshl() functions appeared in 4.3BSD, FreeBSD 2.0, and DragonFly 3.5, respectively. DragonFly 3.9 June 11, 2013 DragonFly 3.9