American River Software
Mathematics
Solutions to exercises from the several standard college textbooks described below are available on each textbook's web page. All solutions are unofficial and intended for educational use. Click on the textbook icon to go to the page and access the PDF files.
Elementary Number Theory
This is an excellent introductory undergraduate text. Unofficial solutions to all the exercises from chapters 1 through 9 (The Quadratic Reciprocity Law) of the 5th edition are available for download.
Elementary Differential Equations and Boundary Value Problems,
This is an excellent undergraduate introductory text. Unofficial solutions to all exercises of the 11th edition from Chapters 1-10 are available for download, including numerous MATLAB code snippets used to solve many of the problems.
Vector Calculus
This is an undergraduate text. Although explanations of some topics may be better and more thorough in other undergraduate texts, the exercises from this book are a bit more challenging, and unofficial solutions to virtually all the exercises in the 6th edition are available for download.
Principles of Mathematical Analysis,
This is the classic undergraduate text used for mathematical analysis. At this time, unofficial solutions to all end-of-chapter exercises for chapters 1 through 7 are available for download, in addtion to detailed comments to each section of the text, filling in many of the missing gaps and explanations.