According to economic theory, the demand x for a quantity in a free market decreases as the price p increases (see the figure). Suppose that the number x of DVD players people are willing to buy per week from a retail chain at a price of Sp is given by x= 10 sp70. Answer parts (A), (B), and (C). 2000- x= 4,000 0.1p+1 4,000 (A) Find dp 0.1p+1' 400 dp (0.1p+1) Demand 1000- 40 Price (dollars) 80 (B) Find the demand and the instantaneous rate of change of demand with respect to price when the price is $40. Write a brief interpretation of these results. The demand is x = 800 when the price is $40. The instantaneous rate of change of demand with respect to price is -16 when the price is $40. Write a brief interpretation of these results. At a price level of $40, the demand is at the rate of DVD players per week and demand is