coordinate geometry shirley sides. 2006. definition grid – a pattern of horizontal and vertical...
TRANSCRIPT
Coordinate GeometryCoordinate Geometry
Shirley Sides.Shirley Sides.
20062006
DefinitionDefinition• Grid – A pattern of horizontal
and vertical lines, usually forming squares.
DefinitionDefinition• Coordinate grid – a grid used to
locate a point by its distances from 2 intersecting straight lines.
1
32
45
0
6
1 2 3 4 50 6
DefinitionDefinition• x axis – a horizontal number
line on a coordinate grid.
1 2 3 4 50 6 x
HintHint• x ‘is a cross’
(across )
1 2 3 4 50 6 x
DefinitionDefinition• y axis – a vertical number line
on a coordinate grid.
12345
0
6
y
DefinitionDefinition• Coordinates – an ordered pair
of numbers that give the location of a point on a grid. (3, 4)
12345
0
6
1 2 3 4 50 6
(3,4)
HintHint• The first number is always the x or first letter
in the alphabet. The second number is always the y the second letter in the alphabet.
1
32
45
0
6
1 2 3 4 50 6
(3,4)
How to Plot Ordered PairsHow to Plot Ordered Pairs• Step 1 – Always find the x value
first, moving horizontally either right (positive) or left (negative).
1
32
45
0
6
1 2 3 4 50 6
(2, 3)
y
x
How to Plot Ordered PairsHow to Plot Ordered Pairs• Step 2 – Starting from your new position
find the y value by moving vertically either up (positive) or down (negative).
1
32
45
0
6
1 2 3 4 50 6
(2, 3)(2,3)y
x
How to Find Ordered PairsHow to Find Ordered Pairs• Step 1 – Find how far over horizontally
the point is by counting to the right (positive) or the left (negative).
1
32
45
0
6
1 2 3 4 50 6
(5, 4)
y
x
How to Find Ordered PairsHow to Find Ordered Pairs• Step 2 – Now count how far
vertically the point is by counting up (positive) or down (negative).
1
32
45
0
6
1 2 3 4 50 6
(5,4)
y
x
What is the ordered pair?What is the ordered pair?
1
32
45
0
6
1 2 3 4 50 6
(3,5)
y
x
What is the ordered pair?What is the ordered pair?
1
32
45
0
6
1 2 3 4 50 6
(2,6)
y
x
What is the ordered pair?What is the ordered pair?
1
32
45
0
6
1 2 3 4 50 6
(4,0)
y
x
What is the ordered pair?What is the ordered pair?
1
32
45
0
6
1 2 3 4 50 6
(0,5)
y
x
What is the ordered pair?What is the ordered pair?
1
32
45
0
6
1 2 3 4 50 6
(1,1)
y
x
Four Quadrants GridFour Quadrants Grid• When the number lines are extended into
the negative number lines you add 3 more quadrants to the coordinate grid.
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
y
x
Four Quadrants GridFour Quadrants Grid• If the x is negative you move
to the left of the 0.
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
x = -2y
x
Four Quadrants GridFour Quadrants Grid• If the y is negative you move
down below the zero.
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
y = -3y
x
How to Plot in 4 QuadrantsHow to Plot in 4 Quadrants• Step 1 - Plot the x number first
moving to the left when the number is negative.
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
(-3, -2)(-3, -2)y
x
How to Plot in 4 QuadrantsHow to Plot in 4 Quadrants• Step 2 - Plot the y number moving
from your new position down 2 when the number is negative.
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
(-3, -2)(-3, -2)
y
x
How to Plot in 4 QuadrantsHow to Plot in 4 Quadrants• When x is positive and y is
negative, plot the ordered pair in this manner.
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
(2, -2)(2, -2)
y
x
How to Plot in 4 QuadrantsHow to Plot in 4 Quadrants• When x is negative and y is
positive, plot the ordered pair in this manner.
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
(-2, 2)(-2, 2)
y
x
Plot This Ordered PairPlot This Ordered Pair
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
(-3, -3)(-3, -3)
y
x
Plot This Ordered PairPlot This Ordered Pair
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
(-1, 2)(-1, 2)
y
x
Plot This Ordered PairPlot This Ordered Pair
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
(1, -1)(1, -1)
y
x
Plot This Ordered PairPlot This Ordered Pair
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
(2, -2)(2, -2)
y
x
Plot This Ordered PairPlot This Ordered Pair
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
(-3, -2)(-3, -2)
y
x
Now try it yourself.Now try it yourself.
• Can you do 1 quadrant or all 4 quadrants?
• Can you make a puzzle for someone else to do?
• Can you find the message?