Cos(45+a).sin(45-a)=1/2(1-sin2a)
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Answer:
Step-by-step explanation:
L.H.S.
= [sin45cosA + cos45sinA].[sin45cosA - cos45sinA]... [ coz sin(A+B) = sinAcosB + cosAsinB and sin(A-B) = sinAcosB - cosAsinB ]
= [sin45cosA]2 - [cos45sinA]2
= cos2A/2 - sin2A/2
= cos2A - sin2A /2
= cos2A .1/2
= R.H.S
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