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Prove:-


(secA - 1)/(secA + 1) = (1 - cosA)/(1 + cosA)



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1 Answer

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= \sf \large ( \sec A - 1)/( \sec \: A + 1 )


= \sf \large ( (1)/( \cos A - 1) )/( (1)/( \cos A + 1 ) )


\sf \large \: = \frac{ \frac{1 - \cos A }{ \green{ \cancel{ \cos A}} }}{ \frac{1 + \cos A }{ \green{\cancel{ \cos A} }} }


\sf \large = (1 - \cos A )/(1 + \cos A )

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