(3) (a) Consider the function U(x) = (x' -1)In(1-x]). What is the domain of the function U(x) (i.e., where it is defined)? Determine whether the function U(x) is odd, even, or neither. Find the critical points of this function and determine its nature. Plot function U(x) and show critical points. (b) Find the critical points of the function V(x, y) = ex (x + ) + 2y) and determine their nature. Plot function cross-sections V(x, y) through the critical points