| Problem in Trigonometry and Complex numbers |
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Michael
Joined: 19 Jan 2004Posts: 17
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Posted: Tue Oct 19, 2004 8:45 pm Post subject: Problem in Trigonometry and Complex numbers
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How to show that
[cos(2pi/13)+cos(10pi/13)][cos(4pi/13)+cos(6pi/13)][cos(8pi/13)+cos(12pi/13)] = 1/8 ?
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Peter
Frequent VisitorJoined: 18 Jan 2004Posts: 110
Location: Hong Kong
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Posted: Fri Oct 22, 2004 1:20 am Post subject: Trigonometry
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= , by
, by using successively
._________________
Therefore do not worry about tomorrow, for tomorrow will worry about itself. Each day has enough trouble of its own.
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