Introduction

Definition

Coordinate geometry refers to:

A system of geometry where the position of points on the plane is described using a pair of numbers.

A plane is a flat surface that goes on forever in both directions thus coordinate geometry is able to tell the exact location where a point is.

The above diagram shows the parts of the coordinate graph. A point on the graph is defined by two given numbers, one is the point on the x-axis and the other is the point on the y-axis. Together, they represent a unique position on the plane.

Thus take for example point K on the graph. Point K has an x value of 3 and a y value of 4. These are the coordinates or sometimes referred to as the rectangular coordinates of point K.

History

The method of describing the location of points in this way was proposed by the French mathematician René Descartes (1596 - 1650). He also made one of the greatest advances in geometry by fusing algebra and geometry. He had even proposed further that curves and lines could be described by equations using this technique. His work’s are thus known as Cartesian coordinates, and its coordinate plane as the Cartesian Coordinate Plane. A myth has it that he was watching a fly on the ceiling when he conceived of locating points on a plane with a pair of numbers. Another mathematician that has also discovered coordinate geometry is Fermat, however the geometry that we are using today is the Descartes version.

References:
http://math.rice.edu/~lanius/Geom/his.html

http://www.ricksmath.com/images/coordinates-point.jpg