2sinx=-√3
sinx=-√3/2
1)x=-π/3+2πn,n∈Z
0≤-π/3+2πn≤2π
0≤-1+6n≤6
1≤6n≤7
1/6≤n≤7/6
n=1⇒x=-π/3+2π=5π/3
2)x=4π/3+2πk,k∈Z
0≤4π/3+2πk≤2π
0≤4+6k≤6
-4≤6k≤2
-2/3≤k≤1/3
k=0⇒4π/3
