Question

БЫСТРОЕ ЗАДАНИЕ! 100 БАЛЛОВ
Пример б)

Answer 1

$\displaystyle (1-cos(2\alpha ))*tg(\frac{\pi }{2}+\alpha )=2*\frac{1-cos(2\alpha )}{2}*(-ctg(\alpha ))=2sin(\alpha )^2*(-ctg(\alpha ))=\\\\-2sin(\alpha )^2*\frac{cos(\alpha )}{sin(\alpha )}=-2sin(\alpha )cos(\alpha )=-sin(2\alpha )$