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प्रश्न
Prove the following:
`(sin x - siny)/(cos x + cos y)= tan (x -y)/2`
उत्तर
We have, बायाँ पक्ष = `(sin x - siny)/(cos x + cos y)`
= `(2sin ((x - y )/2) cos ((x + y)/2))/(2cos ((x - y)/2) cos ((x + y)/2)`
= `(sin (x -y)/2)/(cos (x - y)/2)`
= tan `(x - y)/2` = दायाँ पक्ष।
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