Talk:Cosine of Integer Multiple of Argument/Formulation 6

Is there a particular reason why this result (and the presentation of its proof) was expressed with the negative terms first?

I appreciate that it's not incorrect as such, just that it seems a bit clumsy. It's easier to grasp expressed as:


 * $\cos n \theta = \map \cos {\paren {n - 2} \theta} - 2 \sin \theta \map \sin {\paren {n - 1} \theta}$

Any reason for doing it the way round you did it?

--prime mover (talk) 07:07, 25 February 2021 (UTC)