Functions of two variables - directional derivative
Instructions
1. Key in the function you would like to visualize into the input box.
2. You can click and drag on the 3D curve to zoom in and out, or rotate the curve to see it from all sides.
3. Use the sliders to change the values of a (x-coordinate) and b (y-coordinate) to see point P move on the surface.
4. Move the point to change vector u.
5. Observe how the value of the directional derivative changes as u changes.
6. Refresh the page if anything goes wrong.
