Tuesday, 9 September 2014

trigonometry - Euler formula and sin3

Using the formula:




eiωt=cosωt+isinωt





I would like to prove that:




sin3x=sin3x3sinx4




However I haven't found any approach to this question. Just converting the first formula to sin3 doesn't seem to help as I'm still getting cos3 on the other side. Can anyone help me to guide me on the right way?

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