Materials supplementing the lectures:  Plotting vectors in 3 dimensions (you can also compute the sum, difference, and the cross product) Here is a site that lets you play with quadric surfaces. Here is another one. Here is an applet that lets you draw some contour maps. And here is one that lets you look at all the level curves. Here is a page that lets you play around with the gradient vector and directional derivative on a mountain. Here is another one. Here is an applet that lets you plot vector fields in the plane. Here is a page that talks about the physical interpretation of grad, div, and curl, and has links to cool videos.
Summary of line and surface integration
