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cos (pi/7) cos ((2pi)/(7) ) cos ( (4pi )...

`cos (pi/7) cos ((2pi)/(7) ) cos ( (4pi )/(7) ) =`

A

`1//8`

B

`-1//8`

C

`1//4`

D

`-1//4`

Text Solution

Verified by Experts

The correct Answer is:
B
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