New posts in Roots Of Unity

Minimum polynomial of a root involving the 7th root of unity

Moving from $x^2+x+1=0$ to $x+1+\frac1x=0$ seems to introduce a solution, how is this possible?

Concurrent lines proof for a regular 18-gon

If $ \alpha_i, i=0,1,2...n-1 $ be the nth roots of unity, the $\sum_{i=0}^{n-1} \frac{\alpha_i}{3- \alpha_i}$ is equal to?

Proving $\frac{1}{\cos^2\frac{\pi}{7}}+ \frac {1}{\cos^2\frac {2\pi}{7}}+\frac {1}{\cos^2\frac {3\pi}{7}} = 24$

Find all polynomials $P(x)$ such that $P(x^2)=P(x)^2$

Bounding a sum involving a $\Re((z\zeta)^N)$ term

Finding minimum polynomial of $e^{i\pi/6 }$

Primitive $p^n$-th root of unity in $\bar{\mathbb{Q}}_p$.

$\sum_{\zeta^p=1}(\zeta-1)^n$