ABSTRACT
Most of the models developed in this book are composed of first-or second-order differential equations; this is a common case for physical and industrial models. The tools presented in Chapters 2 through 4 allow us to solve the models and study their responses. Although some analysis of the responses has been done in a few examples, these first-and second-order systems are so important that it is worthwhile to extend the analysis more formally in this chapter. Actually, this discussion also allows us to study the similarities among different systems.
