Hi.I am trying to get a better understanding of the supply curve and how to interpret it. If for example a firm will supply 10 units at a price of US 100 per unit and say 20 at a price of US 120 what does it mean in terms of profitability for the firm.?Does the line represent increasing profitability as prices increases? Perhaps put another way why would a firm not supply at a price below the curve line? Is it because it would not make a profit or not meet its variable costs. Etc.?.
Why is the line also referred to as the marginal cost line and does refer to the whole curve eg zero quantity cannot have a marginal cost?.