A mathematical curve, drawn on a graph, that represents what the demand for a commodity would be if its price ranged anywhere from zero to infinity. The point at which it intersects the supply curve for the same commodity supposedly establishes the price of the commodity in a free market. (See supply and demand.)
A complication must be noticed here, due to my use of the term, "demand curve."
Demand thus varies at different ratios of exchange between goods, and may be expressed graphically by a demand curve.
The demand curve expresses graphically what a man would be willing to pay at each particular stage in the increase of goods.
The new position of equilibrium will be given by the point P', where ss' cuts DD', the demand curve.