Cosine of Integer Multiple of Argument/Formulation 7/Examples/Cosine of Sextuple Angle

Example of Use of Cosine of Integer Multiple of Argument/Formulation 7

 * $\map \cos {6 \theta } = 1 - 2 \sin \theta \paren {\sin 5 \theta + \sin 3 \theta + \sin \theta}$

Proof
Follows directly from the Cosine of Integer Multiple of Argument/Formulation 7:

Explicit derivation illustrated below: