Question

!!!!!Нужна помощь!!!!!

Answer 1

$tg( alpha + beta )= dfrac{tg alpha +tg beta }{1-tg alpha tg beta } \ \ -1= dfrac{3+tg beta }{1-3tg beta } \ \ -1+3tg beta =3+tg beta \ 2tg beta =4 \ tg beta =2$