4 l 2. (20 marks total) Let f (:17, y) = E : + . Find the global minimum and maximum 9 y y of f(a:,y) on the region R = {(51:,y) : 0 S :1: S 2, y 2 1}, or else explain why such global minimum or maximum does not exist, by following the procedure below. (a) (6 points) Find all critical points of f in R. Evaluate f at these points. (b) (8 points) Find the minimum and maximum of f on the boundary of R. (c) (6 points) The region R is not bounded, therefore the theorem about extreme values on compact domains does not apply to D. An additional explanation is needed in order to justify your answer. Please provide that explanation. (Practice Problems 9 include optimization questions on domains that are not bounded. You may want to consult the solutions for examples and templates. It is not enough to say that f(a;,y) > 0 as y > 00 for any xed :13.)