The Total solution for NCERT class 6-12
Let us consider LHS:
cos x / (1 – sin x)
We know that, cos 2x = cos2 x – sin2 x
Cos x = cos2 x/2 – sin2 x/2
Sin 2x = 2 sin x cos x
Sin x = 2 sin x/2 cos x/2
So,