Simpson's Formulas/Sine by Cosine

Theorem

 * $\sin \alpha \cos \beta = \dfrac {\map \sin {\alpha + \beta} + \map \sin {\alpha - \beta} } 2$

where $\sin$ denotes sine and $\cos$ denotes cosine.

Also see

 * Simpson's Formula for Sine by Sine
 * Simpson's Formula for Cosine by Cosine
 * Simpson's Formula for Cosine by Sine