Chapter 12Complex Integrals and Series
In this chapter, we first introduce the complex integral theorems. Despite their simplicity, these theorems are incredibly powerful and establish the basis of complex techniques in applied mathematics. Using analytic continuation, we show how these theorems can be used to evaluate some of the frequently encountered definite integrals in science and engineering. In conjunction with our discussion of definite integrals, we also introduce the gamma and the beta functions, which frequently appear in applications. Next, we introduce complex power series, that is, the Taylor and the Laurent series and discuss classification of singular points. Finally, we discuss the integral representations of special functions.
12.1 Complex Integral Theorems
12.1.1 Cauchy–Goursat Theorem
Let
be a closed contour in a simply connected domain (Figure 12.1). If a given function,
, is analytic within and on this contour, then the following integral is true:
Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Read now
Unlock full access
