If cos theta + cos 7theta + cos 3theta +...

If `cos theta + cos 7theta + cos 3theta + cos 5 theta =0,` then `theta ` is

A

`(npi)/(4)`

B

`(npi)/(2)`

C

`(npi)/(8)`

D

None of these

Verified by Experts

The correct Answer is:

C

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