ABSTRACT

This chapter points out how the ideas of perturbation theory make it possible to exploit the root-finding approach to calculate quantum mechanical expectation values; this strategem is used at several points throughout the book. The root-finding methods used are very simple, since the functions produced by the problems of this book are for the most part well behaved. The root-finding methods which the people use are designed to work effectively for the cos type and tan type functions. The applications of the root-finding approach spread beyond the areas covered in this book, in which the people mainly describe cases for which real single roots of scalar functions are required. In the chapter, the authors describe some simple routines which can be used as components in other programs in this book. The discussion of the chapter has indicated the special methods which are made possible when the root-finding approach is adopted in dealing with the Schrodinger equation of quantum mechanics.