David has a quasilinear utility of the form of U(x, y) = Vx + y, with associated marginal utility functions MUx = 1/(2 vx) and MUy = I. a) Derive David's demand curve for x as a function of the prices, Pr and Py. Verify that the demand for x is independent of the level of income at an interior optimum. b) Derive David's demand curve for y. Is y a normal good? What happens to the demand for y as Px increases