Cosx/2<1/2<br>x/2=+-п/3+2Пk
-П/3+2Пk-2П/3+4Пk2)
sin(x-П/4)>-1/sqrt(2)
sin(П/4-x)<1/sqrt(2)<br>2П+П/4+2Пk>П/4-x>3П/4+2Пk
П/2+2Пk<-x<2Пk<br>-2Пk3) cos(П/6-2x)+sin(П/6-2x)>=1
sin(П/3-4x)>=0
2Пk<=(П/3-4x)<П+2Пk<br>2Пk-П/3<=-4x<2П/3+2Пk<br>-П/12+Пk/2<=-x<=П/6+Пk/2<br>-П/6+Пk/2<=x<=П/12+Пk/2<br>