Find a function where the domain is integers, codomain is real numbers, and image isn't equal to codomain.
The Attempt at a Solution
I know that it means that when I plug in an integer I will obtain a real number, but how do I make it so that the image is not equal to the codomain? I don't quite understand what that means. Does it mean the function is injective?
Here is what I have so far for my first attempt:
However if my x is 2 and -2 I get the same answer. So I am struggling with how to get an injective function.
However here is my second attempt:
f(x) = 1/(x3-3)
Is my second attempt correct?