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Question
Prove the following identity :
secA(1 - sinA)(secA + tanA) = 1
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Solution
LHS = secA(1 - sinA)(secA + tanA)
= `1/cosA(1-sinA)(1/cosA + sinA/cosA)`
= `((1 -sinA))/cosA((1 + sinA)/cosA) = ((1 - sin^2A)/cos^2A)`
= `(cos^2A/cos^2A)`
= 1 = RHS
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