PETER H. SELBY is the author of two other Wiley Self-Teaching Guides: Practical Algebra and Geometry and Trigonometry for Calculus, both revised by STEVE SLAVIN, PhD, who is Associate Professor of Economics at Union County College, Cranford, New Jersey. Dr. Slavin is also the author of All the Math You'll Ever Need: A Self-Teaching Guide and Economics: A Self-Teaching Guide, both available from John Wiley & Sons, Inc.