1) 1-cosx-sinx/2=0
(1-cosx) - sinx/2 = 0
2*sin^2(x/2) - sin(x/2) = 0
sin(x/2)*(2* sin(x/2) - 1 ) = 0
1) sin(x/2) = 0
x/2 = πn, n∈Z
x1 = 2πn, n∈Z
2) 2* sin(x/2) - 1 = 0
sin(x/2) = 1/2
x/2 = (-1)^n*arcsin(1/2) + πk, k∈Z
x/2 = (-1)^n*(π/6) + πk, k∈Z
x2 = (-1)^n*(π/3) + 2πk, k∈Z