Find the number of poles in the right—half plane (RHP) for the system as shown. Is the system stable?

Correct option is A

Given that, Block Diagram

Routh-Hurwitz criteria

As $$\varepsilon$$​​

is very small value, so $$\left( \frac{3\varepsilon - 4}{\varepsilon} \right)$$​​

is a negative value. Hence, there are two sign changes in the first column of R-H table. Therefore, the number of reight half poles = 2 and the system is unstable.