Defined in header <cmath> float atan2( float y, float x ); (1) double atan2( double y, double x ); (2) long double atan2( long double y, long double x ); (3) Promoted atan2( Arithmetic1 y, Arithmetic2 x ); (4) (since C++11)
Computes the arc tangent of y/x using the signs of arguments to determine the correct quadrant.
4) A set of overloads or a function template for all combinations of arguments of arithmetic type not covered by 1-3). If any