nπ±14πn \pi \pm \frac{1}{4} \pinπ±41π
nπ±π2n \pi \pm \frac{\pi}{2}nπ±2π
nπ±π3n \pi \pm \frac{\pi}{3}nπ±3π
2nπ±14π2 \mathrm{n} \pi \pm \frac{1}{4} \pi2nπ±41π