Total revenue. TR ■TR=PQ ■AR=PQQ=P MR=△(PQAQ =(△P*Q)△Q+P*△Qy△AQ =(△P/Q)Q+P(△Q/△Q) =(△P/Q)Q+P Perfect competition: MR=P=AR△P=0Total Revenue: TR ◼ TR = PQ ◼ AR = PQ/Q = P ◼ MR = Δ(PQ)/ΔQ = (ΔP*Q)/ΔQ + (P*ΔQ)/ΔQ = (ΔP /ΔQ ) Q + P(ΔQ/ΔQ ) = (ΔP /ΔQ ) Q + P Perfect competition: MR = P = AR (ΔP =0)