Laurence D. Hoffmann November 2011 I consider myself to be a writer and expositor as well as a mathematician, and these traits led to the original version of this text published in 1975. Before assuming my current position as a Senior Investment Management Consultant with Morgan Stanley Smith Barney, I was a tenured professor of mathematics at Claremont McKenna College, where, on three occasions, I was honored to be the recipient of the Huntoon Award for Excellence in Teaching, a "best-teacher" award determined by a vote of the students. In addition to my current profession and my ongoing involvement with this text, I serve on the Strategic Planning committee of the Claremont Community foundation and on the Investment Committee of the Rancho Santa Ana Botanic Gardens in Claremont. My wife, Janice, and I love to travel, enjoy music and the arts, have two grown sons, three grandchildren and two Maltese dogs. I am an avid (but average) tennis player, am addicted to the Sunday Puzzle on NPR, and have been trying for several years to become fluent in Italian. Long ago, I received by BA in mathematics from Brown University and my Ph.D. in mathematics from the University of Wisconsin.