(1-sin(x))(1+sin(x))=1/1+tan(x^2)
I think the right side is tan^2 x ( the square of tan x)
Left side = 1 - sin^2 x
Right side = 1 / ( 1 + (sin^2 x / cos^2x))
= 1 / (cos^2x + sin^2x) / cos^2 x
Now sin^2 x + cos^2 x = 1 so
this = 1 / 1 / cos^2x
= cos^2x = 1 - sin^2 x = Left side - Proved