Question

sin 3x
(viii) cot-
1 + cos 3x​

Answer 1

A Formula for sin(3x) The prupose of this page is to prove the following formula: \sin 3x =4\sin x\sin(60^{\circ}-x)\sin(60^{\circ}+x). ... The easiest way to do that is to recourse to complex numbers and Euler's formula e^{i\theta}=\cos\theta +\sin\theta.