Question

The ring Z, of integers modulo n is not an integral domain
when n is not prime.​

Answer 1

Step-by-step explanation:

Prove that Zn is an integral domain if and only if n is prime. Proof: If n is not prime, there are integers a and b such that n = ab with 1<a<n and 1<b<n. Then ab = 0 in Zn , but a ≠0 and b ≠0. This means that Zn is not an integral domain.