Can someone help me solve this problem with cyclotomic polynomials? is the n-th cyclotomic polynomial.
1. Let be a non-zero integer, a prime, a positive integer and . Prove that if and only if has period in .
2. Again assume . Prove that for some if and only if
Here's the source of the problem:
Algebra - Google Livres
Page 324, problem 21.
Thanks a lot.