Graphing the Equation of a Line: Introduction

A lot of information is conveyed through graphs.  Company profits, temperature trends, stock prices, and graduation rates are all examples of data that is often displayed using lines and graphs.  From the equations of lines, we can determine how quickly or slowly trends are changing.  In Geometry, we can give the equations of lines and segments that make up the sides of polygons, such as triangles and rectangles, and can use this information to analyze some of their properties.  We also use lines when applying transformations of figures on the coordinate plane.