SA3 marksYear: 2023MediumCBSE Class 10
trigonometryidentitiesproof
Question
Prove that secA1+secA=1−cosAsin2A.
Solution
1
LHS =secA1+secA=cosA11+cosA1=1+cosA.
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=(1−cosA)(1−cosA)(1+cosA)=1−cosA1−cos2A.
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=1−cosAsin2A= RHS. Hence proved.
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