Example
In the cookie factory, the production function is
$$ q \left( K, L \right) = K L^2 $$The marginal product of capital is
$$ MP_K = \frac{d q \left( K, L \right)}{d K} = L^2 $$Question
In the cookie factory, the production function is `q \left( K, L \right) = K^{2} L^{9}`.
What is the marginal product of capital?
$$
MP_K = \frac{d q \left( K, L \right)}{dK} = \frac{d K^{2} L^{9}}{dK} = 2 K^{2 - 1} L^{9} = 2 K^{1} L^{9}
$$