Manpage of ACOS

ACOS

Section: Linux Programmer's Manual (3)
Updated: 2016-03-15
Index
 

NAME

acos, acosf, acosl - arc cosine function  

SYNOPSIS

#include <math.h>double acos(double x);float acosf(float x);long double acosl(long double x);

Link with -lm.

Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

acosf(), acosl():

_ISOC99_SOURCE || _POSIX_C_SOURCE >= 200112L
    || /* Since glibc 2.19: */ _DEFAULT_SOURCE
    || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
 

DESCRIPTION

These functions calculate the arc cosine of x; that is the value whose cosine is x.  

RETURN VALUE

On success, these functions return the arc cosine of xin radians; the return value is in the range [0, pi].

If xis a NaN, a NaN is returned.

If xis +1, +0 is returned.

If xis positive infinity or negative infinity, a domain error occurs, and a NaN is returned.

If xis outside the range [-1, 1], a domain error occurs, and a NaN is returned.  

ERRORS

See math_error(7) for information on how to determine whether an error has occurred when calling these functions.

The following errors can occur:

Domain error: x is outside the range [-1, 1]
errnois set to EDOM. An invalid floating-point exception (FE_INVALID) is raised.
 

ATTRIBUTES

For an explanation of the terms used in this section, see attributes(7).
InterfaceAttributeValue
acos(), acosf(), acosl() Thread safetyMT-Safe
 

CONFORMING TO

C99, POSIX.1-2001, POSIX.1-2008.

The variant returning doublealso conforms to SVr4, 4.3BSD, C89.  

SEE ALSO

asin(3), atan(3), atan2(3), cacos(3), cos(3), sin(3), tan(3)


 

Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUE
ERRORS
ATTRIBUTES
CONFORMING TO
SEE ALSO

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Time: 22:27:55 GMT, June 20, 2016