(4n+1)π4(4 n+1) \frac{\pi}{4}(4n+1)4π
(4n+1)π2(4 n+1) \frac{\pi}{2}(4n+1)2π
(4n−1)π4(4 n-1) \frac{\pi}{4}(4n−1)4π
(4n−1)π2(4 n-1) \frac{\pi}{2}(4n−1)2π