5.5 Suzie purchases two goods, food and clothing. She has the utility function U(x, y)
= xy, where x denotes the amount of food consumed and y the amount of clothing. The
marginal utilities for this utility function are MUx = y and MUy = x.
a) Show that the equation for her demand curve for clothing is y = I/(2Py).
b) Is clothing a normal good? Draw her demand curve for clothing when the level of
income is I = 200. Label this demand curve D1. Draw the demand curve when I = 300 and
label this demand curve D2.
a) At the consumer’s optimum we must have
