Recent content by xuying1209

if n is an odd, cosπ/n+cos3π/n+cos5π/n+...+cos(2n-1)π/n is equal to what? And how can I prove it??

I want to know the minimal polynomial of the field they generate together? Thank you !:wink:

w_{n} is primitive root of unity of order n, w_{m} is primitive root of unity of order m, all primitve roots of unity of order n are roots of Cyclotomic polynomials phi_{n}(x) which is a minimal polynomial of all primitive roots of unity of order n , similarly, phi_{m}(y) is a minimal...

For any n,m are intergers, d_n and d_m are divisors of n and m, respectively. If gcd(n,m)=1, gcd(i,n)=d_n , gcd(j,m)=d_m sm=1(mod n) , tn=1(mod m), z=smi+tnj (mod nm) then gcd(z,nm)=d_nd_m. I want to know the result is true or false, and how to prove...