Customer Reviews

Linear Algebra Demystified

5 star:		(5)
4 star:		(3)
3 star:		(5)
2 star:		(2)
1 star:		(9)

 

 

I really like the format of this book, and I bought it after reading the good reviews on this site. But I have a big problem with the errors in the worked out problems and the problem answers in the book. Pages 30, 31, 64, 102, 233, 234, and 235 contain either mis-printed values or answers that are demonstrably wrong. (One can always check the solution to a set of equations by verifying that they do, in fact, solve the set of equations.) Since I am only up to page 138, there are probably more errors, as well. Given that this is supposed to be a self-teaching guide, this is a definite drawback since the student's first impulse is always to assume that the mistake is their own. Needless to say, this can result in a lot more frustration than required. Even now I'm wondering if I really just missed something, but I don't think so. A book like this really could have used better proofreading (a lot of the mistakes may simply be dropped or duplicated digits). So Caveat Emptor and Caveat Lector.

After reading the author's other book Quantum Mechanics Demystified, I was curious about this work. I was quite surprised. The author's talents are topic selection and presentation. It seems linear algebra books are either theoretical or applied. While this book is clearly of the applied flavor, it steals the gems from the theoretical presentations. Most people who have had linear algebra and are not math majors see matrices as collections of numbers to solve linear systems. While the author covers the solution of linear systems, he shows that Gaussian elimination is a form of reduction which tells us about the problem, not just the solution. By the time you get through QR reduction and singular value decomposition (SVD), you will think of linear algebra in a broader sense. To me this volume corrects a common problem where practitioners think linear algebra = Gaussian elimination + determinants. He brings in the practical perspective from advanced treatments without a cumbersome theoretical framework. As for the quality of the presentation, I must say that when I compared the SVD presentation in LAD to that in Numerical Recipes, I had a strong preference for LAD. By way of critique, I would encourage the author to rework his problems so that they have integer solutions; the manipulation of complex fractions is tedious and detracts from the clarity of the presentation. In closing, this book collects the material you should have in your mind after completing a class in linear algebra.

If your looking for a book to supplement your textbook on Linear Algebra, or a book that provides a mathematical background for a course in Quantum Physics, check out this book. Many textbooks seem to be written at a level that requires the reader to already have a solid understanding of the material being presented. If you don't, you struggle through the book. How many times have you started a chapter on Vector Spaces, Linear Equations, or Matices, only to be lost after the first page or two. David McMahon does an excellent job of giving clear, step-by-step examples, as he walks you through Linear Equations, Matrix Algebra, Determinants, Vectors Spaces, and Eigenvectors. And here's the thing, you understand each topic, as you complete it. I have nothing but the highest praise for David McMahon as an author, who took the essentials of linear algebra, and presented it in a format that is easy to understand, and at the same time fun.

If you agree with this review, and are interested in building on what you learned in "Linear Algebra DeMystified", check out David McMahon's two other books, "Quantum Mechanics DeMystified" and "Relativity DeMystified".

. . . just terrible. I agree with the reviewer that praised the idea behind the book and also with one of the author's stated goals--to provide a quick review for graduate students about to take a more advanced course in linear algebra--but the execution is awful.

This book is replete with errors! Listing them from least to most serious, I found 1)spelling, grammatical and typographical errors 2) MANY computational errors (approximately half of the problems have them) 3) imprecise usage of vocabulary (in a very vocabulary-driven branch of mathematics) 4) SERIOUS errors in definitions and descriptions of procedures (the exposition of one of the most famous algorithms in mathematics, Cramer's Rule (p. 64), IS WRONG!). Also, the few proofs given are worthless except as examples of begging the question, the book in general is poorly written, and--as one reviewer wrote--the answers to the quizzes are incomplete or not given, period.

I am a long-time Amazon customer who orders quite regularly, but this is the first time ever that I have been prompted to write a review. That's how bad this book is. I'm very disappointed; I planned a quick review of linear algebra this summer and do not have time for a textbook-type treatment of the material.

NOTE: I would have given this book zero stars but, as I attempted to publish my review, I discovered that I needed to give it at least one star. It doesn't deserve it.

Shame on the author, the proofreader/editor and publisher. My sympathy goes to those who are just learning linear algebra and perhaps using this book in conjunction with an assigned text; I think they're going to be very confused.

There are so many typos in the examples that I find the book useless. For example, on page 13, the number 13 in the matrix suddenly becomes a 19, and remains the same throughout most of the example. On the top of page 25, the matrix multiplication has three typos! I cannot recommend this book to anyone. The author should have taken more time to check his work.

What is explained is done so clearly, but the book is devoted almost exclusively to the algebraic approach. Those looking for geometric interpretations - say. of eigenvectors - will have to look elsewhere.

I've had a lot of trouble in my college linear algebra class this semester, so to prepare for the final exam I bought this book to supplement my textbook.

The book has had huge pros and huge cons for me, so I'll say a bit about each:

PRO -

This book makes advanced linear algebra techniques insanely easy to understand, by explaining everything at a basic level while still managing to cover advanced techniques and including examples involving complex numbers. The difference in approach to teaching between my textbook and this book are night and day; compared to Demystified, it seems like my textbook is TRYING to make things complicated.

CON -

At the same time, this book has an insane number of typos. You can't trust any of the examples to have the correct answer at the end, nor can you trust the quiz and exam questions to have the correct answers in the back of the book. This book WOULD have been a great self-teaching linear algebra book if the problems had been thoroughly checked, or if there was a comprehensive errata sheet out there (there is an errata sheet, but it barely scrapes the tip of the iceberg of mistakes), but since there are so many errors, this book serves better as a supplemental guide to explaining concepts you might not have understood in class or from a textbook.

I just finished the book and am about half-way through the "final exam" (which is contained in the book, with answers to most problems).

The book seems to cover most or all of the stuff from a first course in linear algebra (upper-division). Plus there seems to be some slightly more advanced material in a few places.

I would not, however, recommend trying to LEARN the subject from scratch, with this book. In fact, I am beginning to see that most of the "Demystified" books, at least the technical ones like math and physics, are more suitable for review and/or reference.

The one thing I would like to see in the book, is more of a "why do we do this?" type of explanation. For example, of what use is a Hermitian conjugate? What does it do for us..does it have any physical meaning? Would it at least help us solve a system of equations? Or what about the Cayley-Hamilton Theorem - who cares if we can formulate a "characteristic equation"? So what..how can we use it (other than solve problems that the theorem applies to)??

Perhaps it is due to my engineering background, that it would seem that this type of thing would be more useful..since engineering is more practically-oriented than pure high-level math.

The author seems confident in his abilities.

So confident that he leaves out steps in arriving at

certain solutions in the early part of the book.

This is ok after you have grasped the material by

going over simpler examples first. The flow is wrong in the beginning of the book. I can see how this would frustrate most people refreshing their

math skills.

My college level book was easier to get into than this

"DeMystified" publication.

I am very dissapointed and wish I could get my money back.

The explainations and examples are better than the text used in my class. Unfortunately, the notations and terminology don't always match our text. If it were up to me, Linear Algebra Demystified would be our primary text. The one I have now should only be used for the excercises.

I am a tutor. Many of my students use the Demystified series to help themselves with math and science. We all recommend the books to each other. Now, I'm recommending them to you!