ATAN2(3)

NAME
atan2, atan2f, atan2l - arc tangent functions of two variables

SYNOPSIS
#include <math.h>
double
atan2(double y, double x);
float
atan2f(float y, float x);
long double
atan2l(long double y, long double x);

DESCRIPTION
The atan2() function computes the principal value of the arc tangent of y/x, using the signs of both arguments to determine the quadrant of the return value. The atan2f() function is a single precision version of atan2(). The atan2l() function is an extended precision version of atan2().

RETURN VALUES
The atan2(), atan2f() and atan2l() functions, if successful, return the arc tangent of y/x in the range [-pi, +pi] radians. If both x and y are zero, the global variable errno is set to EDOM.

SEE ALSO
acos(3), asin(3), atan(3), cos(3), cosh(3), sin(3), sinh(3), tan(3), tanh(3)

STANDARDS
The atan2() function conforms to ansiC.