3.3.1 Production Function roduction function the relationship between quantity of inputs used to make a good and the quantity of output of that good marginal product the increase in output that arises from an additional unit of input diminishing marginal product the property whereby the marginal product of an input declines as the quantity of the le input increases3.3.1 Production Function • production function – the relationship between quantity of inputs used to make a good and the quantity of output of that good. • marginal product – the increase in output that arises from an additional unit of input. • diminishing marginal product – the property whereby the marginal product of an input declines as the quantity of the input increases