Question

Is my reasoning correct?

A function f: Z -> ZxZ defined as f(n)=(2n, n+3) is injective because for all n, 2n and n+3 will map to one and only one element of Z. It is not surjective because 2n will only map to even elements of Z and leave odd elements out.

Answer 1

Yes, that's correct

Answer 2

thanks!