/*
this method returns the difference
of this vector and its parameter.
*/
public Vector2D subtract(Vector2D d2)
{
double a = x - d2.x;
double b = y - d2.y;
return (new Vector2D(a, b));
}
/*
this method returns the sum of this
vector and its parameter.
*/
public Vector2D add(Vector2D d2)
{
double a = x + d2.x;
double b = y + d2.y;
return (new Vector2D(a, b));
}
/*
this method returns the dot product of
this vector and its parameter.
*/
public double dotProduct(Vector2D d2)
{
return (x * d2.x + y * d2.y);
}
