Prove the following identities.

Consider LHS,

LHS = +

We know that sin (90° - θ) = cosθ and cos (90° - θ) = sinθ.

⇒ + = +

We know that = cotθ and = tanθ.

⇒ + = +

= +

= -

=

We know that (a + b) (a – b) = a² – b².

⇒ + =

= cosθ + sinθ = RHS

Hence proved.