A 2 Which of the following two functions is/are surjective and which is/are

injective?

(a) f: N -> Z with f(n) = -n

(b) g: P(M)-> {0, 1, ..., M/ with g(A) = /A], where M is a finite set shall. Does the answer depend on M? If so, specify in which Cases q is injective /surjective and in which it is not.