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Prove that (1+cos""pi/10)(1+cos""(3pi)/1...

Prove that `(1+cos""pi/10)(1+cos""(3pi)/10)(1+cos""(7pi)/10)(1+cos""(9pi)/10)=1/16`

A

`1/8`

B

`1/16`

C

`1/4`

D

1

Text Solution

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The correct Answer is:
B
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AAKASH SERIES-MULTIPLE & SUBMULTIPLE ANGLES-EXERCISE-II
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