What is the profit maximizing rule? Explain using marginal analysis. Why does marginal cost continue to rise, beyond it's minimum point, as output expands? Jacob uses an "inverted stoplight" metaphor for identifying profits vs losses vs shutdown points using cost curves. Explain the "green zone". Now explain what is going on in the "yellow zone" of the inverted stoplight metaphor. Finally, what is happening in the "red zone" of the inverted stoplight metaphor