2nπ−π32 n \pi-\frac{\pi}{3}2nπ−3π
2nπ+π32 \mathrm{n} \pi+\frac{\pi}{3}2nπ+3π
nπ+(−1)nπ6n \pi+(-1)^{n} \frac{\pi}{6}nπ+(−1)n6π
2nπ+′(−1)nπ32 n \pi+{ }^{\prime}(-1)^{n} \frac{\pi}{3}2nπ+′(−1)n3π