Worldwide Pre-Calculus - Kenneth Kuttler
This book emphasizes the topics, which are often a source of difficulty for calculus students: functions, trigonometry identities, binomial theorem, and basic area formulas, for example. However, mathematics does not begin with calculus. There are many fascinating and useful concepts, which can be studied with no exposure to calculus. The book includes some of these, such as applications to finance, probability, partial fractions, and the abstract concept of a field.