Utility maximization is key to deriving the demand function. Because they are equal where utility is maximized, the marginal rate of substitution, the slope of the indifference curve, can be used ...

The marginal rate of substitution is the amount of one good that would be required to satisfy their demand for one additional unit of a substitute good. This rate defines an indifference curve ...

A diminishing marginal rate of substitution implies that an individual requires ... and calculate the price elasticity of demand for apples. 3. Cari Obeck's demand function for tuna is given by: ...