nπ4\frac{n \pi}{4}4nπ
nπ2\frac{n \pi}{2}2nπ
(4n+1)π8\frac{(4 n+1) \pi}{8}8(4n+1)π
(4n+1)π2\frac{(4 n+1) \pi}{2}2(4n+1)π