Let O be the set of odd integers and E be the set of even integers.
Prove that |Z| = |E|
I did get that part then.
Is this right? To show it is onto I said that any x plugged into the function would come out even. Then the image of f is E and thus onto.
To show 1-1, I said for every x plugged into the function, there would be exactly one output, thus 1-1.
How does that sound?