A revision of a much-admired text distinguished by the exceptional prose and historical/mathematical context that have made Simmons' books classics. The Second Edition includes expanded coverage of Laplace transforms and partial differential equations as well as a new chapter on numerical methods.
George Simmons was an American mathematician who worked in topology and classical analysis. He was known as the author of widely used textbooks on university mathematics.
I used this to complement Tenenbaum and Pollard's excellent textbook on the same topic, and though Simmons doesn't show every step of the proofs, the gaps are small enough that you can figure it out on your own after some careful thinking. But it is a bit annoying for sure. The problems are a lot harder—and instructive—than Tenenbaum & Pollard's and all the answers to the exercises are included at the end of the book, so I learned a lot from grappling with the problems (especially Bernoulli numbers/polynomials and their applications!). Some of Simmon's explanations worked better for me than Tenenbaum & Pollard's (like using one solution to find another and Frobenius series), so it was a good idea for me to learn from two textbooks on the same subject.
Reviewing this book as someone who didn't have any prior exposure to ODEs.
I'm really leaning between a 3/4 star here. The book started out rough, where the first 3 paragraphs of chapter 1 were good, only to find out by other people's opinions on mathstackexchange that the other paragraphs of chapter 1 had exercises in them that are introduced way too early! So I had to skip 3/6 paragraphs from the get go due to that.
The rest of the book was fine in that sense, though sometimes when I was reading, I couldn't help but feel as if I was reading a summary, rather than a textbook. The lack of theory is a bit too much, most of which are located in the appendices or the second to last chapter. It was very much about the formulas and knowing how to use them.
It reminds me of when I read a short collection of thoughts by Rota, in which he said that ODEs are taught the wrong way. It's almost like Calculus 2 class, with a bunch of tricks to find the solution of the ODEs, without explaining too much on why they're useful, if they even are useful in practical contexts! This book definitely falls within the class of "The old way of teaching ODEs".
That being said, the book wasn't bad, I skipped chapters 8 and 14, and am sure I will come back eventually to finish those too.
The special thing about this book is that the author provides the readers with historical notes on the stories of the great mathematicians, how the problems were solved and how the theorems were formulated. In any other book on differential equations one can find solutions and methods of solving differential equations, but only a few - this one belongs to those - can one read with passion and curiosity.
It is a pretty good introductory text on ODE. The historical interludes are a nice bonus. But if you are looking for rigor and more details, look somewhere else.