Greetings. I'm sending you this note because you've either signed up for Differential Equations or indicated to me that there was some probability that you would take the class. I want to let you know about the textbook I'm planning to use.
The book is: Paul Blanchard, Robert L. Devaney, Glen R. Hall, Differential Equations (second edition). Brooks Cole. 2002. ISBN: 0534385141
The bad news is that the book new is $111.00. However, there are several ways you could get a book for less.
1. Buy it used online. If you do this, you should be very careful which edition you get. The second edition is the one we want. The first edition is blue, the second edition is white with an orange-ish picture of a bridge. The most reliable indicator of the edition is the ISBN. This is a unique identifier for books; each edition has its own ISBN.
2. But it used at some college bookstore somewhere. This text is used at lots of other colleges and universities. So there's a pretty good chance that you could find it used at a college bookstore somewhere over break.
3. Buy it new via an amazon site in europe. For some reason, textbooks in europe are sold for a much lower price than here in the US. I went to amazon in england: www.amazon.co.uk and looked for our book. New, it costs 32 Pounds. This is just 54 dollars -- less than half what it costs in the US! The French amazon has the book at 49 Euros, which is around 58 dollars.
The book will be on sale at Sherman's, but I'd encourage you to spend a little time over break to save yourselves some money.