2сos^2*t=1
cos^2*t=1/2
1+cos2t/2=1/2
1+cos2t=1
cos2t=0
2t=π/2+πn
t=π/4+πn/2
X^2 - 4X + 4 > X^2 - 4X. X^2 - X^2 - 4X + 4X > 0. Ответ. Нет решений
-42m^10n^8p^6/6m^2n^4p^2=
= -7m^8n^4p^4
1)x<-0,5
2+x+2x+1<-3
3x<-6
x<-2
2)x≥-0,5
2+x-2x-1<-3
-x<-4
x>4
x∈(-∞;-2) U (4;∞)