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8 votes
8 votes
Tan A + sin A/tan A-sin A
= sec A +1/sec A-1

User Adam Ranganathan
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1 Answer

26 votes
26 votes

We need to prove


(\tan A+\sin A)/(\tan A-\sin A)=(\sec A+1)/(\sec A-1)


\text{LHS}=(\tan A+\sin A)/(\tan A-\sin A)\\\\=((\sin A)/(\cos A)+\sin A)/((\sin A)/(\cos A)-\sin A)\\\\=(\sin A+\sin A \cos A)/(\sin A-\sin A \cos A)\\\\=(\sin A(1+\cos A))/(\sin A(1-\cos A))\\\\=(1+\cos A)/(1-\cos A)\\\\=(1+(1)/(\sec A))/(1-(1)/(\sec A))\\\\=(\sec A+1)/(\sec A-1)\\\\ =\text{RHS}

User Leorex
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2.9k points