2. Let f : A - B, f(x) = x2. For each choice of A and B below, state whether the function is injective and whether it is surjective, giving a brief explanation. (In one case, the "function" is not actually a function. Which one?) (a) A= R, B = R (b) A = R, B = [0, 00) (c) A = [0, 00), B = R (d) A = [0, 00), B = [0, 00) (e) A = N, B = N (f) A = Z, B = Z (g) A = R, B = Z