nπ±(−1)nπ4n \pi \pm(-1)^{n} \frac{\pi}{4}nπ±(−1)n4π
2nπ±π32 n \pi \pm \frac{\pi}{3}2nπ±3π
nπ±π3\mathrm{n} \pi \pm \frac{\pi}{3}nπ±3π
nπ+π4\mathrm{n} \pi+\frac{\pi}{4}nπ+4π