Question

How can I prove sin2teta=2costeta×sinteta easily

Answer 1

sin 2Θ= sin(Θ+Θ)

=sinΘ cosΘ+cosΘ sinΘ

=2 cosΘ sinΘ

Answer 2

Sin2tta= sin(tta+ tta) =sintta.costta+ costta.sintta
=2 costta.sintta