## Introduction of co-ordinate Geometry

First it was studied by French Mathematician Rene Descartes in 1637. In this geometry , position of the points is denoted by some special numbers we call them coordinates and we denote different shapes ( lines, circles etc ) with the help of algebraic equations. We use coordinates in this branch of mathematics, so we call it Co-ordinate geometry.

Cartesian Coordinates:

We draw two perpendicular lines in a plane, both are intersecting to each other at a point O, horizontal line is XOX’ and vertical line is YOY’, we call them Coordinate axes or Rectangular coordinate axes or rectangular axes.

Line XOX’ is known as x-axes and line YOY’ is known as y-axes and intersecting point is O, we call it origin.

Let there is a point P in a plane, draw two perpendiculars from point P to x and y axes. Which are PM and PN ( shown in the below figure ), we denote the distance of P point from x-axes is x and from y-axes is y. we call x as x-coordinate or abscissa and y as y-coordinate or ordinate of point P. and these x and y are the coordinates of the Point P. we write them like (x,y).