# 2: Linear and Quadratic Functions

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• 2.1: Linear Functions
Page notifications Off Save as PDF Share Table of contents Contributors We now begin the study of families of functions. Our first family, linear functions, are old friends as we shall soon see. Recall from Geometry that two distinct points in the plane determine a unique line containing those points.
• 2.2: Absolute Value Functions
There are a few ways to describe what is meant by the absolute value |x| of a real number x. The long and short of both of these procedures is that |x| takes negative real numbers and assigns them to their positive counterparts while it leaves positive numbers alone. This last description is the one we shall adopt, and is summarized and discuss in this Module.