Question

Prove that under root (1 + sin x)/ (1 - sin x )= tan ( pi by 4 + x/ 2)

Answer 1

put 1=sin^2 x/2 +cos^2 x/2 and sinx= 2sinxcosx
in both numerator and denominator now you can see complete square of cos x+sinx numerator and cos x-sin x in the denominator
take cos coman and get the ans