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# Complex Variables with Applications (Orloff)

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Complex analysis is a beautiful, tightly integrated subject. It revolves around complex analytic functions. These are functions that have a complex derivative. Unlike calculus using real variables, the mere existence of a complex derivative has strong implications for the properties of the function. Complex analysis is a basic tool in many mathematical theories. By itself and through some of these theories it also has a great many practical applications. There are a small number of far-reaching theorems that we’ll explore in the first part of the class. Along the way, we’ll touch on some mathematical and engineering applications of these theorems. The last third of the class will be devoted to a deeper look at applications. The main theorems are Cauchy’s Theorem, Cauchy’s integral formula, and the existence of Taylor and Laurent series. Among the applications will be harmonic functions, two dimensional fluid flow, easy methods for computing (seemingly) hard integrals, Laplace transforms, and Fourier transforms with applications to engineering and physics.

Thumbnail: Illustration of a complex number showing the multivalued nature of arguments. (CC BY-SA 3.0 Unported; Wolfkeeper via Wikipedia)

Complex Variables with Applications (Orloff) is shared under a CC BY-NC-SA 4.0 license and was authored, remixed, and/or curated by Jeremy Orloff (MIT OpenCourseWare) via source content that was edited to conform to the style and standards of the LibreTexts platform; a detailed edit history is available upon request.