Recipes for Classes of Definite Integrals Involving Exponentials and Logarithms

Abstract

There are many classes of definite integrals for which the corresponding indefinite integral cannot be expressed in closed form whereas the definite integral can be expressed (often in terms of special functions). A computer algebra system should be capable of recognizing a wide variety of definite integrals and, in order to achieve a broad coverage, it is desirable to encode this knowledge in programs which are more general than simple table look-up. By exploiting integral definitions of the various special functions of mathematics and by generalization and differentiation, we are able to derive closed-form solutions for broad classes of definite integrals. In this paper we treat integrals involving exponentials and logarithms. The resulting programs, based on pattern matching and differentiation, are very efficient.