2sinx + 1 = 0

2sin(x)+1=0

sin(x)=-1/2

x=(-1)^n*arcsin(-1/2)+pi*n

x=(-1)^n*7*pi/6+pi*n

2sinx+1=0

2sinx=-1

sinx=-1/2

x=(-1)^(k+1)(arcsin(-1/2)+(pik)

x=(-1)^(k+1)* (pi/6)+(pik)