Kenneth Rosen Edition 7 Exercise 2.3 Question 12 (Page No. 153)

Question

Determine whether each of these functions from $Z$ to $Z$ is one-to-one.

1. $f(n) = n-1$
2. $f(n) =n^2+1$
3. $f(n)= n^3$
4. $f(n) =\left \lceil n/2 \right \rceil$