Find $\sum_{i=1}^{n-1}\frac{1}{2-a^i}$ if $1,a,a^2,...,a^{n-1}$ are the n$^\text{th}$ roots of unity
Series involving complex roots: $\frac{1}{2-a_1} + \frac{1}{2-a_2} + \dots + \frac{1}{2-a_{n-1}} = \frac{(n-2)2^{n-1}+1}{2^n - 1}$