2. Plotting Points  Lesson Objective: Students will know how to plot points on a plane

3. Plotting Points  René Descartes (1596 – 1650) – Known for his saying “cogito ergo sum” “I think, therefore I am”  Developed the Cartesian Plane system we use to plot points today. Uses the x and y axis and 4 quadrants

4. Plotting Points  The Cartesian Plane is mostly known as a “graph”  The graph has two axis The vertical (up and down) is called the y-axis The horizontal (left to right) is called the x-axis

5. Plotting Points  There are 4 quadrants to the graph  They work from the top right in a counter- clockwise fashion

6. Plotting Points  The center of the graph where the two axis meet is call the  At this point, both the x and y values are zero

7. Plotting Points  The lines on the graph represent one unit each  The x-axis works likes a linear graph where the origin is zero and the numbers on the right are positive, the numbers on the left are negative

8. Plotting Points  The lines on the graph represent one unit each  The y-axis works likes the x-axis where the positive numbers go up and the negative numbers go down

9. Plotting Points  When you plot a point, you use the values of x and y to determine where on the graph the point is.  A point always has the x value first, then the y

10. Plotting Points  To find point A, we have to find where it is on the x-axis first  Then we need to find the y value  So point A is known as (1, 3)

11. Plotting Points  Label point B

12. Plotting Points  To find point B, we have to find where it is on the x-axis first  Then we need to find the y value  So point A is known as (-3, 2)

13. Plotting Points  Label points C, D, E, F, and G

14. Plotting Points  What is the vertical axis?  What is the horizontal axis?  What’s the point in the middle called?  What quadrant is point B in?  What quadrant is Point C  For 6 – 10, label the points A – E