ABSTRACT
This will take an inverted U-shape similar to that shown in Figure 9.1. If we ask the question ‘when is TR at its maximum?’ the answer is obviously at M, which is the highest point on the curve. At this maximum position the TR schedule is flat. To the left of M, TR is rising and has a positive slope, and to the right of M, the TR schedule is falling and has a negative slope. At M itself the slope is zero.
