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cos ^(2) (3 pi)/(5)+cos ^(2) (4 pi)/(5)=...

`cos ^(2) (3 pi)/(5)+cos ^(2) (4 pi)/(5)=`

A

`(4)/(5)`

B

`(5)/(2)`

C

`(5)/(4)`

D

`(3)/(4)`

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HIMALAYA PUBLICATION-MEASUREMENT OF ANGLES, TRIGONOMETRIC RATIOS AND RELATION BETWEEN SIDES AND ANGLES OF A TRIANGLE-QUESTION BANK
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