The late Frank Ayres, Jr., Ph.D., was formerly a professor in and head of the Department of Mathematics at Dickinson College, Carlisle, Pennsylvania. He is the author or coauthor of eight Schaum's Outlines, including Calculus, Trigonometry, Differential Equations, and Modern Abstract Algebra.
Philip A. Schmidt, Ph.D., has a B.S. from Brooklyn College (with a major in mathematics), an M.A. in mathematics, and a Ph.D. in mathematics education from Syracuse University. He is currently the program coordinator in mathematics and science education at The Teachers College at Western Governors University in Salt Lake City, Utah.