Q:quantity, FC:fixed cost, VC:variable cost, TC:total cost, AVC:average variable cost, AC:average cost, MC:marginal cost, TR:total revenue, MR:marginal revenue
TC=FC+VC...AVC=VC/Q...AC=TC/Q...MC=delta(TC)/delta(Q)...TR=P x Q
MR=delta(R)/delta(TR)
...delta(Q)
Profit=TR-TC
Based on these...