Prove that sin2 6x – sin2 4x = sin 2x sin 10x
To Prove, sin2 6x – sin2 4x = sin 2x sin 10x
RHS = sin 2x sin 10x
LHS = sin2 6x – sin24x
= (sin 6x – sin 4x) (sin 6x + sin 4x) [a2 – b2 = (a – b)(a + b)]
Rearranging we get
LHS = (2 × sin x × cos x)(2 × sin 5x × cos 5x)
LHS = sin 2x sin 10x [∵ 2sin A cos A = sin 2A]
∴ LHS = RHS
Hence, proved