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Question
Prove that:
`cosA/(1 + sinA) = secA - tanA`
Solution
`cosA/(1+sinA)`
= `cosA/(1 + sinA) xx (1 - sinA)/(1 - sinA)`
= `(cosA(1 - sinA))/(1 - sin^2A)`
= `(cosA(1 - sinA))/(cos^2A)`
= `(1-sinA)/cosA`
= sec A – tan A
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