1) Sin² 50 - Cos²50 = -Sin 100
Ответ:-24 tg 100 = -24 tg(90 + 10) = 24 Ctg 10
2)Sin(-34π/3) = -Sin(34π/3) = -Sin(10π + π/3) = -Sin π/3 = -√3/2
Cos (35π/6) = Cos(5π + 5π/6) = -Cos (5π/6) = √3/2
-√3/2·√3/2 = -3/4
Ответ: -72
3) tg 108 = tg(90 + 18) = -Ctg18
tg198 = tg(180 - 18) = - tg18
-Ctg 18·(-tg18) = 1
Ответ: -42