Question

Упростите: 1)sina/1+cos a
2)$\frac{sina}{1+cosa}$

Answer 1

$\frac{Sin \alpha }{1+Cos \alpha } = \frac{2Sin \frac{ \alpha }{2}Cos \frac{ \alpha }{2} }{2Cos ^{2} \frac{ \alpha }{2} } = \frac{Sin \frac{ \alpha }{2} }{Cos \frac{ \alpha }{2} }=tg \frac{ \alpha }{2}$