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If sin2theta+sin2varphi=1/2a n d\ cos2th...

If `sin2theta+sin2varphi=1/2a n d\ cos2theta+cos2varphi=3/2` , then `cos^2(theta-varphi)=` `3//8` b. `5//8` c. `3//4` d. `5//4`

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Given,

`sin 2θ + sin 2varphi = 1/2`….(i)

`cos 2θ + cos 2 varphi = 3/2`….(ii)

Squaring and adding (i) and (ii),

...
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