Solve for all real values of ϕ\phiϕ in [0,2π)[0, 2\pi)[0,2π) satisfying sin2(ϕ)−12sin(ϕ)≤0\sin^2(\phi) - \frac{1}{2} \sin(\phi) \leq 0sin2(ϕ)−21sin(ϕ)≤0.
[0,π/6]∪[5π/6,2π)[0, \pi/6] \cup [5\pi/6, 2\pi)[0,π/6]∪[5π/6,2π)
[0,π/6]∪[5π/6,π][0, \pi/6] \cup [5\pi/6, \pi][0,π/6]∪[5π/6,π]
[0,π/3]∪[2π/3,2π)[0, \pi/3] \cup [2\pi/3, 2\pi)[0,π/3]∪[2π/3,2π)
[0,π/4]∪[3π/4,π][0, \pi/4] \cup [3\pi/4, \pi][0,π/4]∪[3π/4,π]