[例4]劳斯判据一特殊情况1 D(s)=s+s3+3s2+3s+2 ME369-lecture 6.2 Fall 2015 [例5]劳斯判据一特殊情况2 D(s)=s3+s4+5s3+5s2+6s+6 156 6 15 s 000 s2 s 0 s° x-ju ? s平面有对称分布的根 5u2=j 5,4=±j5 S3=-1 ME369-lecture 6.2 Shanghal Jiao Tong University Fall 2015 99 ME369-lecture 6.2 Fall 2015 4 3 2 D s s s s s ( ) 3 3 2      [例4]劳斯判据—特殊情况1 ME369-lecture 6.2 Fall 2015 School of Mechanical Engineering Shanghai Jiao Tong University 5 4 3 2 D s s s s s s ( ) 5 5 6 6       5 4 3 2 1 0 1 5 6 1 5 6 000 s s s s s s e s平面有对称分布的根 ? 1,2 s j   2 3,4 s j   3 5 s 1 [例5]劳斯判据—特殊情况2