This is about invertible functions,

For the following piecewise-defined function f,

1) determine whether f is 1-1;

2) determine whether f is onto;

3) use the answers to part 1) and 2) to determine whether f is invertible, and if f is invertible, then find the inverse function f^-1

f: Z--> Z by f(n)= n-1 if n is even

n+3 if n is odd