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If alpha+beta+gamma=2 theta then cos t...

If `alpha+beta+gamma=2 theta` then
`cos theta+cos(theta-alpha)+cos (theta-beta)+cos(theta-gamma)=`

A

`4"sin"(alpha)/2."cos"(beta)/2."sin"(gamma)/2`

B

`4"cos"(alpha)/2."cos"(beta)/2."cos"(gamma)/2`

C

`4"sin"(alpha)/2."sin"(beta)/2"sin"(gamma)/2`

D

`4sin alpha.sin beta.singamma`

Text Solution

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The correct Answer is:
B
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