Question

Помогите))  Превратите в произведение 1-2sina

Answer 1

$1-2sin alpha =2(frac{1}{2}-sin alpha )=2(sinfrac{pi}{6}-sin alpha )=\\=2cdot 2cdot sinfrac{frac{pi}{6}- alpha }{2}cdot cosfrac{frac{pi}{6}+ alpha }{2}=4cdot sin(frac{pi}{12}-frac{ alpha }{12})cdot cos(frac {pi}{12}+frac{ alpha }{12})$