let-give-w-e-i-2pi-n-and-Z-k-0-n-1-w-k-2-find-Z-2-in-form-of-double-sum-

Question Number 28166 by abdo imad last updated on 21/Jan/18

l e t g i v e w = e^{i \frac{2 π}{n}} a n d Z = \sum_{k = 0}^{n - 1} w^{k^{2}} f i n d ∣ Z ∣^{2} i n

f o r m o f d o u b l e s u m .