一、請根據下列的成本函數，求出邊際成本函數也就是它們的導數： (a) C(x) = 3 7 5 4 1.5 x  x  x  (5 分)

三、A firm produces a product to sell in a competitive market using capital and labor. Given the production function Y=f(K,L)=KαLβ where Y is output, K is capital input and L is labor input. Suppose that p, r and w are prices of output (Y), capital (K) and labor (L), respectively. Assume that p, r, w are exogeneous and α>0 and β>0 and α+β