can be represented by an isoquant map, a graph combining a number of isoquants, each representing a different quantity of output.An isoquant map can indicate decreasing or increasing returns to scale based on increasing or decreasing distances between the isoquant pairs of fixed output increment, as output increases. If the distance between those isoquants increases as output increases, the firm's production function is exhibiting decreasing returns to scale; doubling both inputs will result in placement on an isoquant with less than double the output of the previous isoquant. Conversely, if the distance is decreasing as output increases, the firm is experiencing increasing returns to scale; doubling both inputs results in placement on an isoquant with more than twice the output of the original isoquant. A firm can choose to utilise the information an isoquant gives on returns to scale, by using it as insight how to allocate resources. Knowing how to allocate resources is a concept pertinent to managerial economics. Isoquants can be useful to graphically represent this issue of scarcity. They show the extent to which the firm in question has the ability to substitute between two different inputs (x and y in the graph) at will in order to produce the same level of output (see: Graph C)). They also represent different quantity combinations of two goods which adhere to a budget constraint. Thus, they can be used as a tool to help management make better informed decisions regarding production and profit dilemmas, such as cost or waste minimization, and revenue and output maximization. A firm can determine the least cost combination of inputs to produce a given output, by combining isocost curves and isoquants, and adhering to First Order Conditions. The least cost combination is where the ratio of marginal products is equal to the ratio of factor prices. At this point, the slope of the isoquant, and the slope of the isocost, will be equal (see intersection of graph D). A firm has incentive to produce at the least cost combination because it is at this point, the related costs of desired production are minimised. As with indifference curves, two isoquants can never cross. Also, every possible combination of inputs is on an isoquant. Finally, any combination of inputs above or to the right of an isoquant results represents a higher level of output, and vice versa. Although the marginal product of an input decreases as