1. +-π/3+πk, k∈z,

2. π/4+πk, k∈z,

3. x+π/3=π/2+πk, k∈z,

x=π/2-π/3+πk, k∈z,

x=π/6+πk, k∈z,

4. cosx=1/2,

x=+-π/3+πk, k∈z,

5. tgx=0,

x=πk, k∈z,

6.4x=π/2+2πk, k∈z,

x=π/8+(1/2π)k, k∈z