Coordinate Geometry

• Introduction
  • Need for Coordinate Geometry
  • Locating a point on a plane
  • Contribution of René Descartes
• Cartesian System
  • Cartesian plane / Coordinate plane
  • X-axis (Horizontal line)
  • Y-axis (Vertical line)
  • Origin ($O$) at $(0, 0)$
  • Intersection of axes at right angles ($90^\circ$)
• Quadrants
  • Division of plane into four regions
  • First Quadrant (+, +)
  • Second Quadrant (-, +)
  • Third Quadrant (-, -)
  • Fourth Quadrant (+, -)
• Coordinates of a Point
  • Ordered pair $(x, y)$
  • Abscissa (x-coordinate / perpendicular distance from y-axis)
  • Ordinate (y-coordinate / perpendicular distance from x-axis)
  • Rules for writing coordinates
• Plotting a Point in the Plane
  • Given coordinates to graph
  • Steps for plotting $(x, y)$
  • Special cases (Points on axes: $(x, 0)$ and $(0, y)$)