According to Wichita State University, Rene Descartes invented the Cartesian Plane, which is a theory of using ordered pairs to determine a specific point. This theory, explained in "La Geometrie," led to the invention of analytical geometry in which algebra is applied to geometry.
Part of the Cartesian Plane theory is the Cartesian coordinate system, a three-dimensional coordinate system. The modern Cartesian coordinate system is often simplified to a two-dimensional system with a horizontal line called the x-axis and a vertical line called the y-axis. The lines are labelled and intersect at the origin point at zero. The location of points between the x- and y-axes are determined by reading the numbers on both axes.
Rene Descartes lived during the 1600s. He started his education at the age of eight, in the Jesuit College in France. Despite frequent ill health, Descartes studied at the college for eight years before moving to Paris to study mathematics. He thought that mathematics was the portal to understanding the science of nature. At the age of 21, in 1617, he joined the army. It was during his military service that he truly started his love affair with mathematics. He left the army in 1621 to devote his time to mathematics, but it took him 17 years to publish "La Geometrie."