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Evaluate: sin78°cos18°-cos78°sin 18° |
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Answer» given equation is in the form sin A ×cos B-cosA×sin B=sin(A-B)given A=78B=18=Sin(78-18)=sin(60)=root3/2 We know that,sinA cosB - cosA sinB = sin(A-B).Here,A=78° and B=18°; therefore sin78° cos18°- cos78° sin18° = sin(78°-18°) = sin 60° =√3/2 |
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