In the initial cournot duopoly equilibrium, both firms have constant marginal costs, m, and no fixed costs, and there is a barrier to entry. show what happens to thebest-response function of firms if both firms now face a fixed cost of f. let market demand bep=a-−bq, where a and b are positive parameters with 2 firms.  let q1 and q2 be the amount produced by firm 1 and firm 2, respectively. assuming it is optimal for the firm one to produce, its best-response function isq1=? ?

Google started as one of many internet search engines, amazon started as an online book seller, and ebay began as a site where people could sell used personal items in auctions. these firms have grown to be so large and dominant that they are facing antitrust scrutiny from competition regulators in the us and elsewhere. did these online giants grow by fairly beating competition, or did they use unfair advantages? are there any clouds on the horizon for these firms -- could they face diseconomies of scale or diseconomies of scope as they continue to grow? if so, what factors may limit their continued growth?