If A+B+C=(3pi)/2. Then cos 2A +cos 2B+co...

If `A+B+C=(3pi)/2`. Then `cos 2A +cos 2B+cos2C` is equal to ................. A) `1-4 cos A cos B cos C` B) `4 sin A sin B sin C`
C) `1+2 cos A cos B cos C` D) `1-4 sin A sin B sin C`

A

`1-4 cos A cos B cos C`

B

`4 sin A sin B sin C`

C

`1+2 cos A cos B cos C`

D

`1-4 sin A sin B sin C`

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The correct Answer is:

D

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