Prove that cos ""(pi)/(9) cos ""( 2pi)/(...

Prove that `cos ""(pi)/(9) cos ""( 2pi)/(9) cos "" (3pi)/(9) cos ""(4pi)/(9) = (1)/(2 ^(4)).`

A

`1/8`

B

`1/16`

C

`1/64`

D

`1/4`

Verified by Experts

The correct Answer is:

B

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