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The value of sum(k=1)^(3) cos^(2)(2k-1)(...

The value of `sum_(k=1)^(3) cos^(2)(2k-1)(pi)/(12),` is

A

0

B

`1//2`

C

`-1//2`

D

`3//2`

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The correct Answer is:
D
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OBJECTIVE RD SHARMA-TRIGONOMETRIC RATIOS AND IDENTITIES-Chapter Test
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  13. The maximum value of cos^(2)A+cos^(2)B-cos^(2)C, is

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