Inequalities, Absolute Value, and Logical Connectives
Algebra students often have difficulty in sorting out and correctly using the concepts involved in the solution of linear inequalities. The introduction of the concept of absolute value causes additional complications for many students. Two of the major problem areas are (1) the concept of absolute value as normally defined and (2) the recognition and appropriate use of the logical connectives and and or in the solution of problems that combine inequalities with absolute value. One way to alleviate students' confusion and promote their problem-solving ability in such a setting is to adopt an approach different from that found in current textbooks. This approach involves consideration of the function concept as the graph generated by associated ordered pairs of real numbers rather than functional values as obtained from the standard definition of absolute value.