QZ. Let a consumer's utility function be U = min (Computer, Operating System). That is, the consumer needs one operating system per computer to be able to use them. a) Derive the consumer's demand function for computers as a function of prices and income. b) Find an algebraic representation for his Engel curve for computer when the price of computer and price of operating system are xed at Po and Ps respectively. Plot the Engel curve using different levels of income