The following functions have {a, b, c, d, e} as both their domain and codomain. For each, determine whether it is (only) injective; (only) surjective; bijective; or neither injective nor surjective:
(a) f = (2 € e) e € b c d e
(b) f = (6 C & e) d (Hint: #X 9(:::9)