Introductory Functional Analysis with Applications

Kreyszig is a well-known author for good reason: his writing is utterly clear and brilliant. He does an excellent job of motivating the techniques and tools he uses in discussion of ideas and concepts, and it'd be hard to ask for a more thorough text. I lament Kreyszig could not have authored books for all my courses, but, for the time being, I'm greatly satisfied with Functional Analysis and Applications.

I can't think of a better place to begin learning functional analysis. The book is ideally suited for undergraduates or beginning graduates who have had one or two semesters of real analysis, linear algebra, and possibly topology. The author seemed extremely lucid with clear worked out examples. Phrases like "it's obvious" or "it should be clear" were not so frequent. It's quite a beautiful subject, with the last chapter providing a nice payoff application in terms of an introduction to quantum mechanics. May be my only complaint was that the exercises seemed mostly five-finger ones. With that said, they should still challenge an undergraduate or beginning graduate, if not force them to re-visit the definitions and basic methods of proof. I've always thought Rudin's "Mathematical Analysis" book deserved the title of "Best Undergraduate Math Text Ever", but this book has made me rethink that position.

The print quality is bad. But no complaints because it's too cheap

This text is for my first course in Functional Analysis. The subject is abstract but enjoyably scientific in flavor; it seems to have many applications outside of pure mathematics. The text is easy enough to read (although some of the proofs are hard to understand) and the exercises are accessible enough that I could recommend it to anyone who has studied Calculus and maybe Linear Algebra. It seems like a book interesting and accessible to students of Physics and Engineering as well as those of Mathematics.

I studied this book for my graduate introduction to functional analysis. It provides a systematic and rigorous approach to the subject. Highly recommend it.

A very good self-study book for beginners in functional analysis. Requires understading of undergrad real analysis

Great book. It was published in the 1980s. Price for such an old book is way too high.

I am about 1/3 way through the text and so far I enjoyed reading the text a lot. The author takes time to explain the theorems and even more importantly emphasizes concepts that are of importance. Excellent book for self study. Highly recommended!

The book came in excellent condition.

I did my bachelor in Mechanical engineering and now I'm catching up on math for research work. I did took an introductory analysis course prior and I find it manageable for self-study to further my knowledge.

It is a very good book.

Não vi nenhum material (nem em português) tão didático sobre o assunto

Un libro que no puede faltar en el estudio del análisis funcional. Cada tema es expuesto de manera clara y los problemas expuestos al final de cada sub tema te ayudarán a reforzar los conocimientos adquiridos.