Suppose that in the inventory problem, the storage cost is a combination of the cost described in the text and the cost described in Exercise 17. In other words, suppose there is an annual cost, k₁, for storing a single unit, plus an annual cost per unit, k₂, that must be paid for each unit up to the maximum number of units stored. Show that the number of units that should be ordered or manufactured to minimize the total cost in this case is

2fM = q= Vk + 2k