Let denote the set of polynomials with rational coefficients and integer constant terms.
Prove that the only two units in are 1 and -1.
Help with this exercise would be appreciated.
Regarding (a) I think the solution is as follows:
We need to show the p is irreducible in
That is if p = ab for p, a, b then at least one of a or b must be a unit
The above is exactly what you must prove for your second post. First what are the units in your ring? I don't believe your "proof". Attached is a correct discussion: