Question

(sin α + sin 2 α)/(1 + cos α + cos 2 α)
пожалуйста срочно

Answer 1

(sin α + sin 2 α)/(1 + cos α + cos 2 α) =
= (sin α + 2 sin α cos α)/(1 + cos α + 2 cos ² α - 1) =
= (sin α + 2 sin α cos α)/(cos α + 2 cos ² α) =
= (sin α (1 + 2 cos α))/(cos α (1 + 2 cos α)) =
= sin α / cos α =
= tg α