A farmer can produce f(x,y)=112/5x2 +y2 units of produce by utilizing x units of labor and y units of capital. Calculate the marginal productivities of labor and capital when x=6 and y=4. Let h be a small number. Use the result of part (a) to determine the approximate effect on production of changing labor from 6 to 6 h units while keeping capital fixed at 4 units. (a) (b) (c) Use part (b) to estimate the change in production when labor decreases from 6 to 5.5 units and capital stays fixed at 4 units.