Finding the Cartesian equation of a plane through 3 points

1. Click to see points A, P, and R; 2. Click to see vectors OA (a), AP (u), PR (v) and OR (r); 3. Click to see the normal vector n; 4. Click to see the Cartesian equation of the plane; 5. Move the sliders for lambda and mew to see different points R(x, y, z) in the plane