Помогите решить задания
P=Пи, э-принадлежит
1.cosx>-1/2
-2P/3+2Pn>x>2P/3+2Pn, nэz
2.sinx>=1/2
P/6+2Pn<=x<=P-P/6+2Pn, nэz</p>
3. cosx/2>√3/2
-P/6+2Pn
-P/3+4Pn
4. sin2x<=-1/2</p>
-P-7P/6+2Pn<=2x<=7P/6+2Pn, nэz</p>
-P/2-7P/12+Pn<=x<=7P/12+Pn, nэz</p>