Comments on Lesson VC.04

This is a great lesson to schedule the same week as your first exam. It is easy to handle and just about everybody does well.

G.4 "The most important field of all: The gradient field." A must assign. The wonderful (and easy) questions that ask what the net flow of a field is across some small circle around a maximizer really set the stage for the problems in later sections.
G.6 This problem briefly raises the question "Can trajectories in a vector field cross?" A more challenging addition would be to ask whether it is possible for to trajectories to join together. That should provide for some more brain-food for those who wrestle with it. (Looking at the negative field would tell you the answer.)