Prove the following: cosA / 1 - sinA = tan (45 + A/2)

L.H.S=cos A1-sin A

=cos 2A21-sin 2A2

=cos2A2-sin2A2sin2A2+cos2A2+2sinA2cosA2

=cosA2+sinA2cosA2-sinA2cosA2+sinA22

=cosA2-sinA2cosA2+sinA2

=1-tanA21+tanA2  (Dividing both numerator and denominator by cosA2)

=tan45°+A

=R.H.S

Hence Proved.
 

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