EQUATIONS OF SCIENCE 
LESSON 4. Cartesian Coordinate System The specialized line graph that uses the Cartesian Coordinate System is not only a way to show data, but it is useful in interpreting data. It allows the user to compare two to three variables that can help the researcher see a relationship with the data. The term "Cartesian" is derived from the French mathematician and philosopher Rene Descartes (15961650) who was noted for his logical and mechanical interpretation of the physical world. The story goes that as Descartes was sick in bed, he looked up toward the tiled ceiling. He would try to track a fly buzzing around and realized he could track the position of the fly by using a coordinate system. Even if the story is not true, there was something that sparked his interest. Descartes introduced a way to specify the position of a point or object on a surface by using two intersecting number lines. His work has influenced the development of analytic geometry, calculus, and cartography. A number line is a straight line with directions either radiating from a center. Right of the center on the number line is positive numbers and left is negative numbers. Two number lines that are perpendicular to each other are defined as a Cartesian coordinate system. This system developed a way in which Euclidian geometry and algebra could be graphically represented.
