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sin^2 6°-sin^2 12°+sin^2 18°-sin^2 24°......15 solve it

sin^2 6°-sin^2 12°+sin^2 18°-sin^2 24°......15 solve it

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Grade:12th pass

1 Answers

Akhand
23 Points
6 years ago
(1-cos2x6)/2 +(1-cos24)/2+ …......................+(1-cos180)/2
15/2 -1/2(cos12 +cos24...........+cos180) use cos(a)+cos (a+b) +cos(a+2b)+....(cos(a+nb)=
{sin(nb/2)cos[a+(n-1)b/2]}/sinb/2
sin90xcos96/sin6=-1

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