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If A +B = ( pi )/( 3) and cos A + cos B ...

If `A +B = ( pi )/( 3)` and `cos A + cos B =1`, then which of the following are true `:`

A

`cos ( A- B ) = ( 1)/( 3)`

B

`cos ( A-B ) = - ( 1)/( 3)`

C

`| cos A - cos B | = sqrt( 2//3 )`

D

`| cos A - cos B |= ( 1)/ ( sqrt( 3))`

Text Solution

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The correct Answer is:
B, C
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ML KHANNA-TRIGONOMETRY RATIOS AND IDENTITIES-MISCELLANEOUS EXERCISE (SELF ASSESSMENT TEST)
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