In (a)the demand curve facing the firm is perfectly elastic, even though the market demand curve in (b)is downward sloping. The demand curve facing an individual firm in a competitive market is both its average revenue curve and its marginal revenue curve.Along the demand curve,marginal Revenue, average revenue,and price are all equal.In (a) the demand curve facing the firm is perfectly elastic, even though the market demand curve in (b) is downward sloping. The demand curve facing an individual firm in a competitive market is both its average revenue curve and its marginal revenue curve. Along the demand curve, marginal Revenue, average revenue, and price are all equal