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If `270^(@) lt A lt 360^(@), 90^(@) lt B lt 180^(@) , cos A =5//13 , tan B=-15//8 " then " cos (A+B)=`

A

`(140)/(221)`

B

`(171)/(221)`

C

`(140)/(171)`

D

`(221)/(171)`

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The correct Answer is:
B
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AAKASH SERIES-COMPOUND ANGLES-EXERCISE - II
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  16. If Cot A Cot B = 2 & Cos (A+B) = 3/5 then Sin A Sin B

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