The Leaving Cert

The short run and long run economic concepts regarding a firm, its profits and costs.
These are incomplete, Ill publish them now but I plan to work on them over time. Fixed costs are those that do not change as output changes. Variable costs are those that do.
The short run is a period of time in which at least one of the factors of production are fixed in quantity.
The long run is a period sufficiently long for all the factors of production to be varied.

AFC = FC/Q
AVC = VC/Q

AC = AFC + AVC = FC/Q+VC/Q

MC = →TC(change in total cost)

When MC is rising then AC is falling. When MC is falling then AC is rising. When MC = AC, Ac stays the same on a graphical representation of Marginal and Average Costs.MC cuts AC at the lowest point on AC.