please help me with this question. This is complete question with no missing components.

Problem 3 Under our usual assumptions consider a sealedbid allpay auction in which every buyer submits a bid, the highest bidder receives the good, and every buyer pays the seller the amount of his big regardless of whether he wins. Compare the seller's expected revenues in such an auction with the seller's expected equilibrium revenues from the usual rst price auction. Derive a symmetric equilibrium bidding function for the all pay auction. Justify your answers carefully