Problem Set 4 From: Mash-Erdene Ganbold (1154248) 1. (a) y = A·L·f(k) = A L f I K AL ,1M = A L f Hk,1L r = MP K = ΔY ΔK = Δy ΔK r = ΔIAL f I K AL ,1MM ΔK = A L f ' I K AL ,1M 1 AL = f ' Hk,1L = f ' HkL Using chain rule: f(g(x)) = f’(g(x))·g(x), where f HgH xLL = f I K AL ,1M gH xL = K AL (b) y = A·L·f(k) = A L f I K AL ,1M w = MP L = ΔY ΔL = Δy ΔL w = ΔIAL f I K AL ,1MM ΔL = A f ' I K AL ,1M - K AL 2 L + A f I K AL ,1M = A· f ' I K AL ,1M - K AL + A f I K AL ,1M = AA f ' I K AL ,1M - K AL + f I K AL ,1ME = A[f(k)-kf’(k)] Using product & chain rule: (f·g)’ = f’·g+f·g’ where f H xL = A f I K AL ,1M gH xL = L