Com conhecimento das $\text{Fórmulas de Werner}$:\begin{matrix} z &=&[ \ \cos{(2x)}.\sin{(2x)} \ ]^2.\sin{(x)} &=& {\large{[ \frac{\sin{(4x) + \sin{(0)}}}{2} ]^2}} . \sin{(x)} &=& 2^{-2}\sin{(4x)}. \sin{(4x)}. \sin{(x)} \end{matrix}Continuando, \begin{matrix} z &=& 2^{-2}\sin{(4x)}. {\large{[ \frac{\cos{(5x) \ - \ \cos{(3x)}}}{-2} ]}} &=& 2^{-3} [\sin{(4x)}\cos{(3x)} - \sin{(4x)}\cos{(5x)} ] \end{matrix} \begin{matrix} z &=& 2^{-3} {\large{[ \frac{\sin{(7x) \ + \ \sin{(x)}}}{2} - \frac{\sin{(9x) \ - \ \sin{(x)}}}{2} ]}} \end{matrix}Por fim, \begin{matrix} z &=& 2^{-4} \ [\ 2\sin{(x)} + \sin{(7x)} - \sin{(9x)} \ ] \end{matrix} \begin{matrix} Letra \ (B) \end{matrix}