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If the value of cos((2pi)/7) + cos((4pi)...

If the value of `cos((2pi)/7) + cos((4pi)/7)+cos((6pi)/7)+cos((7pi/7))=-l/2` Find the value of `l`

A

1

B

`-1`

C

`1/2`

D

`(-3)/(2)`

Text Solution

Verified by Experts

The correct Answer is:
D
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