From abelian group to zero divisor (definitions), and from Artin-Wedderburn theorem to Wedderburn's theorem, this site provides concise explanations of complex concepts in abstract algebra. Provided by Professor John A. Beachy of Northern Illinois University as a companion to two books he has written, it is designed as a handbook for students studying the topic. The site is accessible by chapter...

Cornell University hosts this impressive collection of Historical Math Monographs, made available for free public viewing online. The default option for reading the books is to view pages as images within a Web browser, but users can also choose to view text only; another option is to view pages as pdf files (but this may not be working properly). Many authors have works showcased in the...

High school or college students taking an introductory trigonometry course may find this site useful. Three modules comprise the site, and each provides an overview of basic concepts. Some of the most common trigonometric identities are explained and illustrated in example problems. Each module is accompanied by an interactive set of problems that test the user's understanding of the concepts....

Math students will find this online textbook to be a valuable study aid to complement their lecture notes and standard class text. It is intended to help students, especially those majoring in mathematics, make the transition from standard math classes to more rigorous, advanced topics and abstract theory. Spanning over 200 pages, the text covers "basic set theory, induction, quantifiers,...