Again: under perfect competition MR=△(PQ/AQ =(△P*Q)/△Q+(P△QAQ =(△P/Q)Q+P(△Q/△AQ) When AP=o (price taking →MR=P Decision rule: z is maximized when mrep=mcAgain: under perfect competition ◼ MR = Δ(PQ)/ΔQ = (ΔP*Q)/ΔQ + (P*ΔQ)/ΔQ = (ΔP /ΔQ ) Q + P(ΔQ/ΔQ ) When ΔP=0 (price taking) → MR =P Decision rule: is maximized when MR=P=MC