For each of the functions below, indicate whether the function is onto, one-to-one, neither or both. If the function is not onto or not one- to-one, give an example showing why. (a) f: RR. f(x) = x (b) g: R R. g(x) = x (c) h: ZZ.h(x) = x (d) f: Z Z. f(x) = -4 (e) f: ZZ. f(x) = 5x - 4 (f) f:ZZ f(x) = x - 4 (9) f: ZxzZ+ZxZ, f(x, y) = (x+1, 2y) (h) f: ZxZ+ZxZ, f (x, y) = ([5] , v ) (1) f: ZxZ+ZxZ. f(x,y) = (1,5-2) () f: Zxz ZxZ, f(x, y) = (1-y, 1-x) (k) f: Z+xZ+ Zt. f(x, y) = 2 + y.