4. [18] Best buds, Sohail and Jimmy are binge watching The Price is Right when the covid lockdown starts. They are essentially marooned in Jimmy's apartment (think of this as a deserted island). Although they are unable to produce anything, they are very fortunate and each ofthem has a supply of cookies (0) and Mountain Dew (d) . Sohail has 6 cookies and 3 bottles of Mountain Dew, while Jimmy has 3 cookies and 6 bottles of Mountain Dew. Although they like the same products, they have different preferences over them,- Sohail's utility function is U(c, d) = Cd2 and Jimmy's utility function is U(c, d) = 4c2d. The lockdown friends decide to engage in trade. a. [6] Without normalizing prices, find their demand functions for each good. b. [2] Write the excess demand function for cookies