Here are some equations to guide your study of the cost and product curves, as well as perfect competition sections before Midterm #2.

AP_L = Q/L

MP_L = DQ/DL

TC = TFC + TVC

TFC = Sunk Costs + Recoverable FC

AC = TC/Q

AFC = TFC/Q

AVC = TVC/Q

Profits = (P - AC)Q

Profits = (P x Q) - TC

Where: Q = output
L = labor
AP_L = average product of labor
MP_L = marginal product of labor
TC = total cost
TFC = total fixed costs
TVC = total variable costs
AC = average (total) cost
AFC = average fixed cost
AVC = average variable cost