5. Explain in what sense the expenditure minimization problem (the Hick- sian demand problem) is a "dual" representation of the consumer choice problem to the utility maximization problem (the Marshallian demand problem). (a) write now both problems for the case of utility function that represents strictly convex preferences (for example, when u(21,*2) is strictly concave) (b) Define the value function in each problem, and interpret it (with words). (c) Then, using the value function definition in the two problems, show how: i) a Hicksian demand can be computed as a Marshallian demand. ii) a Marshallian demand can be computed as a Hicksian demand