1. Use the following two-good utility functions to answer parts a) through d). (1) Many) = 3x + y [2) U (x, y) = 9623' [3) U (x, y) = W? (4) U (any) = min {my} a) Graph indifference curves for U0 = 3 and U0 = 6 for each of the above utility functions. Label each indifference curve with the utility it provides. To avoid confusion, draw a new xyplane for each utility function. 13) Starting at (x = 1, y = 1), nd the marginal utility of good x for each of the above utility mctions. c) Find the marginal rate of substitution of utility function (1). d) Which utility functions from (1) to (4) show a preference for variety