  Sum rules have played an important role in the development of many branches
of physics since the earliest days of quantum mechanics. We present examples of
one-dimensional quantum mechanical sum rules and apply them in two familiar
systems, the infinite well and the single delta-function potential. These cases
illustrate the different ways in which such sum rules can be realized, and the
varying mathematical techniques by which they can be confirmed. Using the same
methods, we also evaluate the second-order energy shifts arising from the
introduction of a constant external field, namely the Stark effect.
