Question

(sina+tga):tga=1+cosa

Answer 1

$\frac{ \sin(a) + tg(a)}{tg(a)} = 1 + \cos(a)$

$\frac{ \sin(a) + tg(a)}{tg(a)} = \frac{ \sin(a) }{tg(a)} + \frac{tg(a)}{tg(a)} = \frac{ \sin(a) }{ \frac{ \sin(a) }{ \cos(a) } } + 1 = \\ \\ = \cos(a) + 1$


Тождество доказано