ABSTRACT
Some of our demonstrations may have seemed somewhat incomplete for their lack of labeling. It is often important to include notation in plots. In fact, sometimes it is the connection between the notation and the geometry that really constitutes the essence of the idea you are demonstrating. For example, think of the concept of choosing two values, a and a+h, evaluating a function at both a and a + h, then letting h→ 0. You want to demonstrate that what this accomplishes geometrically is the movement of one point along the x-axis toward another and, at the same time, the movement of an associated point along a curve toward another. You are really explaining the notation; you need to have it in the plot.
