Тригонометрия! 1)cost > -1/2 2)sinx-корень3cosx< -1

1
cost>-1/2
4π/3+2πk<t<8⇒/3+2⇒k,k∈z
2
sinx-√3cosx<-1
2(1/2*sinx-√3/2*cosx)<-1
2sin(x-π/3)<-1
sin(x-π/3)<-1/2
7π/6+2πk<x-π/3<11π/6+2πk
3π/2+2πk<x<13π/6+2πk,k∈