Question

1-cos2y+sin2y/sin(П/2-y) + siny = 2 siny​

Answer 1

$frac{1-Cos2y+Sin2y}{Sin(frac{pi }{2}-y)+Siny }=frac{2Sin^{2}y+2Siny Cosy }{Cosy+Siny}=frac{2Siny(Siny+Cosy)}{Cosy+Siny}=2Siny\\2Siny=2Siny$

Тождество доказано