Memory Demand TermsVersion en ligne Econ Ch4.1 par Kim Jacoway The willingness, ability and desire to buy a product Law of Demand The quantity of a good or service demanded varies inversely with the price. Chart that shows the amount an individual is willing to pay for an item at multiple price points. Market Demand Curve Marginal Utility Graph that shows the amount an individual or a market will pay for a product at multiple price points Demand the extra usefulness or satisfaction a person gets from acquiring or using one more unit of a product the principle which states that the extra satisfaction we get from using additional quantities of the product begins to diminish. Individual Demand Schedule Diminishing Marginal Utility Utility the amount of usefulness or satisfaction that someone gets from the use of a product or service.