ACOS(3) Linux Programmers Manual ACOS(3)
NAME
acos, acosf, acosl  arc cosine function
SYNOPSIS
#include
double acos(double x);
float acosf(float x);
long double acosl(long double x);
Link with lm.
DESCRIPTION
The acos() function calculates the arc cosine of x; that is the value
whose cosine is x. If x falls outside the range 1 to 1, acos() fails
and errno is set.
RETURN VALUE
The acos() function returns the arc cosine in radians and the value is
mathematically defined to be between 0 and PI (inclusive).
ERRORS
EDOM x is out of range.
CONFORMING TO
SVr4, POSIX.12001, 4.3BSD, C89, C99. The float and long double vari
ants are C99 requirements.
SEE ALSO
asin(3), atan(3), atan2(3), cacos(3), cos(3), sin(3), tan(3)
COLOPHON
This page is part of release 3.05 of the Linux manpages project. A
description of the project, and information about reporting bugs, can
be found at http://www.kernel.org/doc/manpages/.
20041006 ACOS(3)
