1) sinx ≥ √2/2
arcsin(√2/2) + 2πn ≤ x ≤ π - arcsin(√2/2) + 2πn, n∈Z
π/4 + 2πn ≤ x ≤ π - π/4 + 2πn, n∈Z
π/4 + 2πn ≤ x ≤ 3π/4 + 2πn, n∈Z
2) sinx ≥ 1/2
arcsin(1/2) + 2πn ≤ x ≤ π - arcsin(1/2) + 2πn, n∈Z
π/3 + 2πn ≤ x ≤ π - π/3 + 2πn, n∈Z
π/3 + 2πn ≤ x ≤ 2π/3 + 2πn, n∈Z
3) sinx< - √3/2<br>- π - arcsin(- √3/2) + 2πn < x < arcsin(- √3/2) + 2πn, n∈Z
-π + π/3 + 2πn < x < - π/3 + 2πn, n∈Z
-2π/3 + 2πn < x < - π/3 + 2πn, n∈Z
4) sinx < -(√2/2)<br>- π - arcsin(- √2/2) + 2πn < x < arcsin(- √2/2) + 2πn, n∈Z
- π + π/4 + 2πn < x < - π/4 + 2πn, n∈Z
- 3π/4 + 2πn < x < - π/4 + 2πn, n∈Z