In a monopolistic market, there is no price function which determines the quantity that a company will offer to the market at a particular price. On the contrary, the quantity that a company offers is determined by the demand curve it faces entirely. That means under monopoly there is no correspondence between quantity supplied and price. This is due to the fact that a monopolist output decision depends on shape of the demand curve and the marginal cost. Thus, demand shift cannot trace out a series of quantities and prices as it is with competitive supply curve.