Hey can some one tel me how do i go about solving this question Let m be a positive fixed interger and l be an integer that is not divisible by m prove 1 + w^l + w^2l + .... + w^(m-1)l = 0 all the w's have subscript "m". Thanks
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Originally Posted by flaming 1 + w^l + w^2l + .... + w^(m-1)l = 0 I assume that $\displaystyle \omega = e^{2\pi i/m}$ Then, $\displaystyle \omega^l = e^{2\pi il/m}\not = 1$ since $\displaystyle m\not | l$. Now use geometric sum, $\displaystyle \frac{1 - (\omega^l )^{m}}{1-\omega^l} = 0$.
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