For each of the functions below, indicate whether the function is onto, one-to-one, neither orboth. If the function is not onto or not one-to-one, give an example showing why.

(a)f1:Z→Z. f1(x) =x33
(b)f2:Z→Z. f2(x) =bx3c+ 23
(c)f3:Z×Z→Z×Z. f3(x, y) = (x+ 1,2y)3
(d)f4:Z+×Z+→Z+.f4(x, y) = 2x+y−1