In this seventh edition, we continue on the path established in previous editions. Quoting from the preface of the sixth edition, we "retain the same features that have made the book popular: ease of reading so that the instructor does not have to 'interpret the book' for the student, many illustrative examples that often solve the same problem with different procedures to clarify the comparison of methods, many exercises from which the instructor may choose appropriately for the class, more challenging problems and projects that show practical applications of the material." ...