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


16