Question

Тригонометрия 10 класс. 30 БАЛЛОВ!!!

Answer 1

$a) (tg alpha +ctg alpha ) ^{2} =3 ^{2} \ tg ^{2} alpha +2tg alpha *ctg alpha +ctg ^{2} alpha =9 \ tg alpha *ctg alpha=1 \ tg ^{2} alpha +2*1 +ctg ^{2} alpha =9 \ tg ^{2} alpha +ctg ^{2} alpha =9-2 \ tg ^{2} alpha + ctg ^{2} alpha =7$

$b) frac{ frac{3sin alpha }{cos alpha } - frac{4cos alpha }{cos alpha } }{ frac{5sin alpha }{cos alpha } + frac{6cos alpha }{cos alpha } } = frac{3td alpha -4}{5tg alpha +6} = frac{3*(-3)-4}{5*(-3)+6} = frac{-9-4}{-15+6} = frac{-13}{-9} = frac{13}{9} =1 frac{4}{9}$