# atan2

ATAN2(3) Linux Programmer's Manual ATAN2(3)
NAME
atan2 - arc tangent function of two variables
SYNOPSIS
#include <math.h>
double atan2(double y, double x);
DESCRIPTION
The atan2() function calculates the arc tangent of the two variables x
and y. It is similar to calculating the arc tangent of y / x, except
that the signs of both arguments are used to determine the quadrant of
the result.
RETURN VALUE
The atan2() function returns the result in radians, which is between
-PI and PI (inclusive).
CONFORMING TO
SVID 3, POSIX, BSD 4.3, ISO 9899
SEE ALSO
acos(3), asin(3), atan(3), cos(3), sin(3), tan(3)
1993-06-08 ATAN2(3)