prove that cos 2B - cos 2A / sin 2A + sin 2B = tan (A-B)
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LHS =(cos2B - cos2A)/( sin2A + sin2B)
use formula ,
sinA +sinB =2sin (A +B)/2 .cos (A-B)/2
cosB-cosA =2sin (A+B)/2.sin (A-B)/2
now,
=2sin (A+B).sin (A-B)/2sin (A+B).cos (A-B)
=tan (A +B) =RHS
use formula ,
sinA +sinB =2sin (A +B)/2 .cos (A-B)/2
cosB-cosA =2sin (A+B)/2.sin (A-B)/2
now,
=2sin (A+B).sin (A-B)/2sin (A+B).cos (A-B)
=tan (A +B) =RHS
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