public double CrossProduct(_2DVector v) { return((X * v.Y) - (Y * v.X)); }
public _2DVector Subtract(_2DVector v) { return(new _2DVector(X - v.X, Y - v.Y)); }
public double Scalar(_2DVector v) { return((X * v.X) + (Y * v.Y)); }
public _2DVector Add(_2DVector v) { return(new _2DVector(X + v.X, Y + v.Y)); }