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nguyenbahiep1

[laTEX]w^2 -w+1 =0 \\ \\ TH_1: w_1 = \frac{1}{2} + \frac{\sqrt{3}}{2}i = cos(\frac{\pi}{3})+sin(\frac{\pi}{3})i \\ \\ (w_1)^{2008} = cos(\frac{2008.\pi}{3})+sin(\frac{2008\pi}{3})i = -\frac{1}{2} - \frac{\sqrt{3}}{2}i \\ \\ \frac{1}{(w_1)^{2008}} = -\frac{1}{2} + \frac{\sqrt{3}}{2}i \\ \\ \Rightarrow (w_1)^{2008}+\frac{1}{(w_1)^{2008}} = - 1\\ \\ TH_2: w_1 = \frac{1}{2} - \frac{\sqrt{3}}{2}i [/laTEX]

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