Prove the following trigonometric identities:
(1+sin θ)2+(1−sin θ)22 cos2θ=1+sin2θ1−sin2θ
We know that cos2θ+sin2θ=1
LHS=(1+sinθ)2+(1−sinθ)22cos2θ
=1+2sinθ+sin2θ+1−2sinθ+sin2θ2cos2θ
=2+2sin2θ2cos2θ
=2(1+sin2θ)2cos2θ
=1+sin2θcos2θ
=1+sin2θ1−sin2θ=RHS