2. Define the function f : Z17× -> Z17× by f(x) = x-1, for all x in Z17×. Is f one to one? Is f onto? If possible, find the inverse function f-1.
3. (a) Let be a fixed element of Sn. Show that f : Sn -> Sn defined by f() = -1, for all in Sn, is a one-to-one and onto function.
(b) In S3, let = (1,2). Compute the corresponding function f defined in part (a).