Question

Sin(П/4)cosx+cos(П/4)*sinx<-√2/2

Answer 1

sin(π/4+x)<-√2/2
5π/4+2πn<π/4+x<7π/4+2πn
5π/4-π/4+2πn<x<7π/4-π/4+2πn
π+2πn<x<3π/2+2πn
x∈(π+2πn;3π/2+2πn)