This review concerns the second edition of "Mathematical Analysis I" of V. A. Zorich.
This is a very good and modern book that covers in great details all the usual topics (and additional ones as well) of a first course in mathematical analysis.
The author often introduces the topics with an informal discussion of their main concepts and theorems, to which a historical digression on the motivations that lead to the development of that part of mathematical analysis follows.
The mathematical theories are also very often presented in combination with scientific problems in the natural sciences, which helps to frame the theory in its applied framework. For example, Chapter 5 (Differential Calculus) starts with a very detailed and insightful discussion on how the desire to express mathematically the change in trajectory of a moving body leads naturally to the definition of the derivative.
The book addresses its content in great detail and several theorems and examples are presented in each chapter.
The mathematical proofs are generally very clear and elegant and the author leaves few statements without proof and often encourages the reader to work out the proof himself.
The level of rigour in the book is high, even though some concepts are sometimes presented in an informal way, as it is the case with the tangent space in chapter 5.
This is related to the fact that the author tries from the beginning to expose the topics in a very general and modern form, which might lead to the inclusion of concepts from more advanced areas of mathematics which do not belong to a first course of mathematical analysis.
For this reason the book is, in my opinion not suitable as a first book in mathematical analysis, but the reader should have a previous exposure to the presented topics. It remains however an excellent choice for a second book on this subject.
While the author gives several examples, I believe that these are sometimes not sufficient and more counter examples would be beneficial in those sections dealing with more abstract topics, which are plenty, given the author's inclination in presenting the topics from a very general point of view. Exercises are also plenty but no solutions are provided.
Overall I would give this book an 8/10: this is an extremely good second book on mathematical analysis, from which the serious reader can learn a lot and can obtain a more general understanding of the topics presented in other mathematical courses.
More counter examples and some solutions to the exercise would make the book one of the best choice for studying mathematical analysis.