Question

Prove that :cos 27° + sin51° = sin63° + cos 39°

Answer 1

Taking LHS = cos 27° + sin51^o

We know that

cos θ = sin (90° - θ)

Here, θ = 27°

⇒ sin (90° - 27°)+ sin 51°

⇒ sin 63°+ sin 51°

We also know that

Sin θ = cos (90° - θ)

Here, θ = 51°

⇒ sin 63°+ cos (90° - 51°)

⇒ sin 63°+ cos 39° = RHS

Hence Proved