S1=｛β|2k180°<β<2k180°+90° k∈Z｝ P1=｛β|2kπ<β<2kπ+π/2 k∈Z｝S2=｛β|2k180°+90°<βS3=｛β|k180 °<β<2k180°+270° k∈Z｝ P3=｛β|kπ<β<2kπ+(3π)/2 k∈Z｝S4=｛β|2k180°+270°°<β<2(k+1)180°k∈Z｝ P4=｛2kπ+(3π)/2<β<2(k+1)π k∈Z｝
