2cos (П/6-x/2) ≥ tg3П/4 Срочно, помогите

2cos (П/6-x/2) ≥ tg3П/4 (tg (3П/4)=-12cos (П/6-x/2) >=-1cos (П/6-x/2) >-1/2-2П/3+2Пn <= П/6-x/2 <= 2П/3+2Пn; n e Z-2П/3-П/6+2Пn <= -x/2 <= 2П/3-П/6+2Пn; n e Z -5П/6+2Пn <= -x/2 <= П/2+2Пn; n e Z 5П/6-2Пn>=x/2>=-П/2-2Пn; n e Z 5П/3-4Пn>=x>=-П-4Пn; n e Z