A farmer can produce f(x, y)equals216 StartRoot 5 x squared plus y squared EndRoot units of produce by utilizing x units of labor and y units of capital. (a) Calculate the marginal productivities of labor and capital when x equals 12 and y equals 3. (b) Let h be a small number. Use the result of part (a) to determine the approximate effect on production of changing labor from 12 to 12 plus h units while keeping capital fixed at 3 units. (c) Use part (b) to estimate the change in production when labor decreases from 12 to 11.5 units and capital stays fixed at 3 units.