Symmetric Properties of Routh–Hurwitz and Schur–Cohn Stability Criteria

It is often noticed in the literature that some key results on stability of discrete-time systems difference equations are obtained from their corresponding continuous-time differential using suitable conformal mappings or bilinear transformations. Such observations lead to search for a unified approach study root distribution real and complex polynomials, with respect left-half plane (Routh–Hurwitz stability) unit disc (Schur–Cohn stability). This paper further contribution toward this objective. We present, systematic way, similarities, yet, differences between these two types stability, we highlight symmetry exists them. also illustrate how conveyed through proposed techniques. should be mentioned Schur–Cohn known harder obtain than Routh–Hurwitz ones, giving more credibility approach.