In: Advanced Math
(a) Let n be odd and ω a primitive nth root of 1 (means that its
order is n). Show this implies that −ω is a primitive 2nth root of
1. Prove the converse: Let n be odd and ω a primitive 2nth root of
1. Show −ω is a primitive nth root of 1. (b) Recall that the nth
cyclotomic polynomial is defined as Φn(x) = Y gcd(k,n)=1 (x−ωk)
where k ranges over 1,...,n−1 and ωk = e2πik/n is a primitive nth
root of 1. Compute Φ8(x) and Φ9(x), writing them out with Z
coefficients. Show your steps.