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Welcome Back to
Grade 8
Mathematics!
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Linear Relations
and Functions
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Rectangular
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Coordinate System
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Rectangular
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Coordinate System
Also called, the
CARTESIAN
COORDINATE
PLANE
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Rectangular
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Coordinate System
In Mathematics, the
cartesian plane is
defined as a twodimensional coordinate
plane, which is formed
by the intersection of
the x-axis and y-axis.
The x-axis and y-axis
intersect perpendicular
to each other at the point
called the origin.
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Rectangular Coordinate System
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• French
mathematician René
Descartes (1596 –
1650) who is known
as the “Father of
Modern
Mathematics”, came
up with this idea of
his coordinate
system, the
CARTESIAN
PLANE.
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Parts of the Cartesian Plane
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• Cartesian Plane is
composed of two
perpendicular
number lines that
meet at the point
of origin (0,0) and
divided the plane
into four regions
called Quadrants.
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Parts of the Cartesian Plane
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Parts of the Cartesian Plane
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(-4,5)
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Parts of the Cartesian Plane
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Plotting Points in the Cartesian Plane
(5, 6) is an example of an ordered pair.
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(5, 6)
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Plotting Points in the Cartesian Plane
(5, 6) is an example of an ordered pair.
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(5, 6)
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(x, y)
It is like entering a hotel …
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up the elevator
in the door
(– 3, 4)
(– 3, 4)
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up 4
left 3
Plot the following points.
A(– 4, 6)
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B(2, – 3)
C(– 6, – 4)
D(7, 3)
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Plot the following points.
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A(– 4, 6)
B(2, – 3)
A(– 4, 6)
C(– 6, – 4)
D(7, 3)
D(7, 3)
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C(– 6, – 4)
B(2, – 3)
These points all lie in different quadrants.
What do you notice about their coordinates?
Plot the following points.
E(5, 0)
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F(0, 6)
G(– 7, 0)
H(0, – 3)
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Plot the following points.
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E(5, 0)
F(0, 6)
F(0, 6)
G(– 7, 0)
E(5, 0)
H(0, – 3)
G(– 7, 0)
H(0, – 3)
These points all lie on the axes, not in quadrants.
What do you notice about their coordinates?
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Plot the following points
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(0,6)
(-4,0)
(2,0)
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(0,-3)
Mind Activity:
• How can be a
Rectangular
Coordinate
System be used
in real life?
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?
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Uses:
• Finding a
particular place
in the map
• Locate the seat of
your classmate
using ordered
pairs
• Cartesian plane is
used in drawing
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Let’s Try This!
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• Book Activity
page page 122123, Exercises
A #1-3.
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