- Implicit Differentiaion & Related Rates Course Packet on computing elasticity of demand using implicit differentiation The demand function for a certain brand of compact discs is given by p = -2x2 - 5x + 80 where p is the wholesale unit price in dollars and x is the quantity demanded each week, measured in units of a thousand. (a) Compute the price, p, when x = 5. Price, p 5 dollars (b) Use implicit differentiation to compute the rate of change of demand with respect to price, p, when x - 5. Do not round your answer. Rate of change of demand, x' = thousands of units per dollar X (c) Compute the elasticity of demand when x = 5. Do not round your answer. Elasticity of Demand Submit