The functions are .

To find .

                      (Substitute g(2) = 5)

                                 (Substitute g(1) = 0)

                       (Substitute g(2) = 9)

                                  (Substitute g(3) = 6)

has no elements  in the function g, so not exist.

To find

                                 (Substitute f(7) = 0)

                       (Substitute  f(5) = 3)

                          (Substitute  f(8) = 3) 

     (Substitute  f(9) = 2) 

has no element  in the function f, so not exist.

  and not exist.