7. Consider the following three functions defined on the set where both variables take on positive values. 1 (* 1) *2 ) = In( $ 1 82 + x 7 + 5 ) W ( x 1 ) * 2) = $1 ( * 1 + * 2 ) " ( * 1 , * 2 ) = e it x 2 a) Which two functions have identical level maps? Justify your answer. b) Which functions, if any, are homogeneous? As usual, justify your