Consider the following production function: f(k,l)= 10kl/k+l (a) Derive the conditional input demand functions. (b) Derive the long-run total cost, marginal cost and average cost functions. (c) State and verify Shephard's lemma for the functions derived in (a) and (b). (d) When wk = 4 and wl = 1, plot the long-run total cost, average cost and marginal cost functions