If A+B+C=270^(@) then cos2A+cos2B+cos2C=...

If `A+B+C=270^(@)` then `cos2A+cos2B+cos2C=`

A

`1-4sinA sinB sinC`

B

`1-4cosA cosB cosC`

C

`4sinA sinB sinC`

D

`1+2 cos A cos B cosC`

Text Solution

Verified by Experts

The correct Answer is:

A

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AAKASH SERIES-TRANSFORMATIONS AND INDENTITIES-EXERCISE -I

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