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Prove that (cosalpha+cosbeta)^2+(sinalph...

Prove that `(cosalpha+cosbeta)^2+(sinalpha+sinbeta)^2=4cos^2((alpha-beta)/2)dot`

A

`4 sin ^(2) ( alpha - beta ) //2`

B

`4 cos^(2) ( alpha - beta ) //2`

C

`4 sin^(2) ( alpha + beta ) //2`

D

`4 cos ^(2) ( alpha + beta ) //2`

Text Solution

Verified by Experts

The correct Answer is:
B
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