Transcript Graphing using a Cartesian Plane

Graphing
using a Cartesian Plane
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.”

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.

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.

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)
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
over…You FALL!
Plotting Points
(2,5,)
(-4,7)
(-5-2)
(6,-4)
Interactive Lesson Time!
Pick 2 numbers between 1 and 20.
 Randomly make one, both or none of
them negative.
 Graph them here.
