Graphing using a Cartesian Plane

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Graphingusing a Cartesian Plane
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Vocabulary

• Cartesian Plane - named after the mathematician
  Rene Descartes (1596 - 1650), is a plane with a
  rectangular coordinate system that associates
  each point in the plane with a pair of numbers.
• Famous for saying, I think, therefore, I am.

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• Coordinates - A unique ordered pair of numbers
  that identifies a point on the coordinate plane.
  The first number in the ordered pair identifies
  the position with regard to the x-axis while the
  second number identifies the position on the
  y-axis
• Graph - A visual representation of data that
  displays the relationship among variables,
  usually cast along x and y axes.
• Origin the point (0,0) - where the X axis and Y
  axis cross.

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Quadrants

• There are 4 quadrants (big surprise) marked with
  Roman Numerals I, II, III, IV.
• They are numbered Counter Clockwise starting with
  the upper right.

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Quadrants
Quadrant X(horizontal) Y(vertical) Example
I Positive Positive (3,2)
II Negative Positive (-4,1) 
III Negative Negative (-2,-1)
IV Positive Negative (3,-7) 
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Plotting Points

• (x,y) is how we write Coordinate Pairs.
• X always comes first. Always!
• When graphing, Go over, then up.
• Remember, walk over to the ladder then climb. If
  you climb then go overYou FALL!

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Plotting Points
(2,5,) (-4,7) (-5-2) (6,-4)
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Interactive Lesson Time!

• Pick 2 numbers between 1 and 20.
• Randomly make one, both or none of them negative.
  
• Graph them here.