Problem 1 (2 marks). Let f: 1R?Hr > ]R be defined by f(x) 2 xi\" - - 46%\

x}n, where > 0 Problem 1 (2 marks). Let f: Rn + R be defined by f (x) x 1 for all j , n. This function, called Cobb-Douglas, is broadly used in economics. Show that for all e Ril and all j Can we conclude that f is differentiable everywhere on its domain? If so, write down for arbitrary O.