Slide 1

Rene Descartes

The idea of graphing with coordinate axes dates all the way back to the 1600s, gets the credit for coming up with the two-axis system we use today. The story goes that he lay in bed and watched flies crawling over tiles on the ceiling. He realized that he could describe a fly's position using the intersecting lines of the tiles. The system is often called the "Cartesian coordinate system" in his honor.

Plotting Points on the Coordinate PlaneJune 21, 2012Todays ObjectiveI can plot points on the coordinate plane using ordered pairs of integers.

But first DEFINITIONS!I love defining things. It helps people understand things better. Like a liger its a cross between a lion and a tiger.

Coordinate Grid Is used to locate and name points on a plane. The grid is formed by two perpendicular lines.

IntegerA whole positive or negative numberThe Coordinate PlaneDefinition:The plane containing the X and Y axis.

What does it look like?

The Coordinate Plane

8X-AxisDefinition:The HORIZONTAL axis in the coordinate plane.How will I remember:X was walking along one day. He fell flat on his face because he is a 0. The x-axis is the axis that is flat on its face.ORStretch your arms out.your arms stretched out represents the x-axis.X-AxisWhat does it look like?

x-axisY-AxisDefinition:The VERTICAL axis in the coordinate plane.How will I remember?Y TO THE SKY!

Y-AxisWhat does it look like?

y-axisOriginDefinition:The point (0,0) on the coordinate plane. It is where the x-axis and the y-axis intercept.How will I remember?Origin means the beginning. The origin of the coordinate plane is the beginning of the graph.It is usually (but not always) in the middle.OriginWhat does it look like?

originOrdered PairDefinition:Set of two numbers where the first coordinate represents the horizontal position (the x), and the second coordinate represents the vertical position (the y). How will I remember?Pair means 2. Order means first, second. An ordered pair then tells you which to graph first and which to graph second (x,y).Ordered PairWhat does it look like?(14,-3)xyX-CoordinateDefinition:The coordinate that corresponds to the x-axis. It is the x point.How will I remember?X comes first in the alphabet. It is the first point given in the ordered pair!!X-CoordinateWhat does it look like?(14,-3)x-coordinateY-CoordinateDefinition:The coordinate that corresponds to the y-axis. It is the y point.How will I remember?Y comes second in the alphabet. It is the second point given in the ordered pair.Y-CoordinateWhat does it look like?(14,-3)y-coordinateQuadrantDefinition:One of the four quarters in the coordinate plane.How will I remember?Quad sounds like quatro. Both mean 4.QuadrantWhat does it look like?Quadrants are labeled with the letter Q and Roman numerals. They are listed like:QIQIIQIIIQIVQuadrants on the Coordinate Plane

Hint: To remember the order of the quadrants, draw a CWhat good are the quadrants?The quadrants tell you which point is negative and which point is positive.If you memorize the quadrants, you will know exactly where to place a point.What good are the quadrants?

(+,+) or (x,y)(-,+) or (-x,y)(-,-) or (-x,-y)(+,-) or (x,-y)Plotting Points

For one BILLION dollars, I will show you how to make a plot!MWHAHAHAHAHA!!!Steps for Plotting PointsTo plot a point, follow these steps:

1.)Start at the origin2.)Locate the x-coordinate If the x-coordinate is positive, travel to the right. If the x-coordinate is negative, travel to the left.3.)Locate the y-coordinate If the y-coordinate is positive, travel up. If the y-coordinate is negative, travel down.4.)Label the pointPlot the Following Points on the Coordinate PlaneA = (1,4)B = (0,0)C = (-2,-4)D = (5,7)E = (2,-3)Name the Ordered PairIFHGJF = ( , )G = ( , )H = ( , )I = ( , )J = ( , )

Now it is time for you to practice on your own!

#Leggo!

Pull out your Independent Practice and begin working quietly. No talking, You have about 12 minutes.