cosx≤ -1/2 ;2πk+ π - π/3 ≤ x ≤ π + π/3 + 2πk ;2πk+ 2π/3 ≤ x ≤ 4π/3 + 2πk . -----------------------------------------------sinx ≥1/2 ;2πk+ π/6 ≤ x ≤ π - π/6 + 2πk ;2πk+ π/6 ≤ x ≤ 5π/6 + 2πk .-----------------------------------------------tqx ≤ 1 ;πk - π/2 ≤ x ≤ π/4 + πk .-----------------------------------------------ctqx ≥ -1 ;πk +0 ≤ x ≤ π-π/4 + πk ;πk ≤ x ≤ 3π/4 + πk.