Rule 6: Brea kaway and break-in Points on the Realaxis Break-in point O Breakaway point Use the following necessary condition dg(sh(s-o of dsL(s)H(s) dk 0 or B=0 ds ds P61(6)P6)=02 S+Ei Stpi 上潇人字 SHANGHAI ILAO TONG UNIVIRSITY 2021/1/262021/1/26 5  j Break-in point  j Breakaway point Rule 6: Breakaway and Break-in Points on the Real Axis Use the following necessary condition P(s)Z(s)− P(s)Z(s) = 0    ( ) ( ) ( ) ( ) 0 d d 0 or 1 d d 0 or d d = =       = s K s s G s H s G s H s g i pj s z s + =  +  1 1