Roots of Unity (1 Viewer)

monkeysdance · Nov 10, 2016

Q17 pt 1

Mahan1 · Dec 4, 2016

monkeysdance said:
Q17 pt 1

$\textrm{well, the roots of -1 are}$
$[cis(\frac{\pi}{8}) , cis(\frac{-\pi}{8}) ] ,[ cis(\frac{3\pi}{8}),cis(\frac{-3\pi}{8})] , [cis(\frac{5\pi}{8}), cis(\frac{-5\pi}{8})] , [cis(\frac{7\pi}{8}), cis(\frac{-7\pi}{8})]$

$\textrm{by paring roots in the square brackets you get the first part.}$

$\textrm{letting} x = x+1, a = x-1 \ \textrm{in the first part and using} \ \ cos \ 2\theta + 1= 2 cos^{2}\theta$
$\textrm{ will give you the second part}$

Roots of Unity (1 Viewer)

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