1. Suppose a firm's total cost function is given by: TC = 50Q 1.5Q% + 0.05Q + 20K + 10L where Q = represents the quantity of output produced, K = represents the quantity of capital employed, and L = represents the quantity of labour employed. (a) Calculate the marginal cost (MC) function with respect to output (Q). (b) Using the total differential, estimate the change in total cost when the quantity produced increases from 40 units to 45 units, with the quantities of capital (K) and labour (L) employed increasing from K =10to K=15and L =5to L = 8, respectively. (c) Interpret the result in terms of marginal cost, economies of scale, and input substitution