Step 1: Option (A) is correct because for oscillations to occur, the system must be of at least second order.
Step 2: Option (B) is correct because oscillations with decaying amplitude are a characteristic of underdamped poles, which are found in second order systems.
Step 3: Option (C) is incorrect because a system with oscillations must have at least one real or complex pole.
Step 4: Option (D) is incorrect because a first order system cannot exhibit oscillatory behavior.
Thus, the correct answers are (A) and (B).
Final Answer:
(A) that it is of at least second order, (B) that it has at least one pole-pair that is underdamped.
Consider the loop transfer function \(\frac {K(s+6)}{(s+3)(s+5)}\). In the root locus diagram the centroid will be located at:


