These are extended problems in which students explore either a mathematical concept or an application. Some investigations extend ideas presented in the section.
Some investigations foreshadow topics that students encounter in later sections.
Investigations can be used as part of a regular homework assignment, group homework, a small group in-class activity, or as a class discussion. Four investigations from various parts of the book are given below. The federal income tax laws are quite complicated. There have been various proposals to simplify the system. Many of these proposals are often referred to as a flat tax.