9. Suppose the production of electricity requires just two inputs, capital and labor, and that the production function is Cobb–Douglas. Now consider the isoquants corresponding to three different levels of output: Q !

100,000 kilowatt-hours, Q ! 200,000 kilowatt-hours, and Q ! 400,000 kilowatt-hours. Sketch these isoquants under three different assumptions about returns to scale:

constant returns to scale, increasing returns to scale, and decreasing returns to scale.