4. Using your favorite method, derive the intertemporal optimality conditions for t = 0, 1: at) = 6(1 + 1r)U'(e+i)- What are the implications of this optimality condition for cl, (:2 and c3. 5. Assume b0 = 0 and = 1 and r = 0. Solve for consumption Co, net exports 711:0, and current account care, by dening the concept of permanent income ,2}. Interpret your results by providing examples for dierent cases of yo and 9;. Discuss intuitively hovvr the result change in each of the cases: be 0