(Answered) The point at which the marginal physical product curve for a particular input is falling and lies…

➤ How can I identify this point on a product curve diagram?
Plot both curves: APP peaks where MPP and APP meet. After that intersection, the MPP curve lies below APP and slopes downward. Identify the region between the APP maximum and where MPP hits zero. That interval is Stage II, where MPP < APP and average product falls.