To Prove: Taking LHS, [ ∵ cos 2x = cos 2 x – sin 2 x] Using, (a 2 – b 2 ) = (a – b)(a + b) = cos x + sin x = RHS ∴ LHS = RHS Hence Proved

Prove that

To Prove:

Taking LHS,

[∵ cos 2x = cos²x – sin²x]

Using, (a² – b²) = (a – b)(a + b)

= cos x + sin x

= RHS

∴ LHS = RHS

Hence Proved