Question

Помогите решить
tg(x+2y)
sin(x-2y)
cos(2x-2,5y)
tg(x-2y)

Answer 1

tg(x+2y) =(tgx+tg2y)/(1-tgxtg2y)
sin(x-2y) =sinxcos2y-cosxsin2y
cos(2x-2,5y)=cos2xcos2,5y+sin2xsin2,5y
tg(x-2y)=(tgx-tg2y)/(1+tgxtg2y)

Answer 2

$1)tg(x+2y)= \frac{tgx+tg2y}{1-tgxtg2y} \\ \\ 2)sin(x-2y)=sinxcos2y-cosxsin2y \\ \\ 3)cos(2x-2.5y)=cos2xcos2.5y+sin2xsin2.5y\\\\4)tg(x-2y)= \frac{tgx-tg2y}{1+tgxtg2y}$