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sum(r=1)^(n-1)cos^(2) (rpi)/2 is equal t...

`sum_(r=1)^(n-1)cos^(2) (rpi)/2` is equal to

A

`n/2`

B

`(n-1)/(2)`

C

`n/2`

D

none of these

Text Solution

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The correct Answer is:
C
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OBJECTIVE RD SHARMA ENGLISH-TRIGONOMETRIC RATIOS AND IDENTITIES-Exercise
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