THE_CHARACTERISTIC_EQUATION_OF_A_CONTROL_SYSTEM_IS_GIVEN_BY_S6+2S5+8S4+12S3+20S2+16S+16=0_._THE_NUMBER_OF_THE_ROOTS_OF_THE_EQUATION_WHICH_LIE_ON_THE_IMAGINARY_AXIS_OF_S-PLANE:?$

THE_CHARACTERISTIC_EQUATION_OF_A_CONTROL_SYSTEM_IS_GIVEN_BY_S6+2S5+8S4

1.	THE_CHARACTERISTIC_EQUATION_OF_A_CONTROL_SYSTEM_IS_GIVEN_BY_S6+2S5+8S4+12S3+20S2+16S+16=0_._THE_NUMBER_OF_THE_ROOTS_OF_THE_EQUATION_WHICH_LIE_ON_THE_IMAGINARY_AXIS_OF_S-PLANE:?$
A.	0
B.	2
C.	4
D.	6
Answer» D. 6