In-class exercise: finding total and
marginal product.
• Suppose the production function is
• $f(L, K) = LK + K$
• What is the marginal product of capital (in general)? Hint: $\frac{\partial xy}{\partial x} = y$
• What is the marginal product of capital when $(L, K) = (10, 10)$?
• What is the total product when $(L, K) = (10, 10)$?
• Answers: $MP_K = L + 1$, $MP_K(10, 10) = 10 + 1 = 11$, $f(10, 10) =$
$10 \times 10 + 10 = 110$