CO - ORDINATE GEOMETRY

CO - ORDINATE GEOMETRY

1. Cartesian plane

   • Invented by Rene Descartes
     • French Mathematician (17th century )
   • Used for describing the position of a point on a plane
   • Denoted by (x,y)
     • x -coordinate is called Abscissa
     • y - coordinate is called Ordinate
   • 4 Quadrants
     • -x,+y
     • +x,-y
     • +x,+y
     • -x,-y

2. Fixed Point (Point where x and y axes intersect)

   • Origin (0,0)
     • -ve y axis (-y,0)
     • -ve x axis (-x,0)
     • +ve y axis (+y,0)
     • +ve x axis (+x,0)

3. Equations

   • Equation of x axis
     • y=0
   • Equation of line parallel to x axis
     • y=a (constant)
   • Equation of line parallel to x axis
     • x=a (constant)
   • Equation of y axis
     • x=0

4. Pointing on a cartesian plain

   • Draw a coordinate axis and select units
     • starting from origin, mark the abscissa and ordinate.
       • mark the point of intersection.

5. Drawing Graph of Linear equation

   • Convert the given equation if the form y = mx + c
     • Select at least 3 values of x and y
       • Draw a table for the ordered pair
         • Plot the ordered points on the graph paper
           • Draw a straight line passing through the points