How can I simplify sin2xcosx+cos2xsinx?

1 Answer
May 28, 2015

Use the identities: sin 2x = 2sin x.cos x and

cos 2x = 2cos^2 x - 1

2sin x.cos^2 x + (2cos^2 x - 1)sin x =

=sin x(4cos^2 x - 1) = sin x.(2cos x - 1)(2cos x + 1)