Evaluate underset(r=1)overset(n-1)sum c...

Evaluate ` underset(r=1)overset(n-1)sum cos^(2) ((rpi)/(n))`.

A

0

B

1

C

`(1)/(2) (n-2)`

D

`(1)/(2)(n-1)`

Verified by Experts

The correct Answer is:

C

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