Download - Coordinate geometry
Coordinate GeometryCoordinate Geometry
by Monica Yuskaitisby Monica Yuskaitis
Copyright © 2000 by Monica Yuskaitis
DefinitionDefinition Grid – A pattern of horizontal and Grid – A pattern of horizontal and
vertical lines, usually forming vertical lines, usually forming squares.squares.
Copyright © 2000 by Monica Yuskaitis
DefinitionDefinition Coordinate grid – a grid used to Coordinate grid – a grid used to
locate a point by its distances from locate a point by its distances from 2 intersecting straight lines.2 intersecting straight lines.
ABCDE
1 2 3 4 5
What are the coordinates
for the house?
Copyright © 2000 by Monica Yuskaitis
DefinitionDefinition x axis – a horizontal number line x axis – a horizontal number line
on a coordinate grid.on a coordinate grid.
1 2 3 4 50 6 x
Copyright © 2000 by Monica Yuskaitis
HintHint x is the shortest and likes to lie x is the shortest and likes to lie
down horizontally. down horizontally.
1 2 3 4 50 6 x
Copyright © 2000 by Monica Yuskaitis
DefinitionDefinition y axis – a vertical number line on y axis – a vertical number line on
a coordinate grid.a coordinate grid.
12345
0
6
y
Copyright © 2000 by Monica Yuskaitis
HintHint y is the tallest and stands upright or y is the tallest and stands upright or
vertically.vertically.
12345
0
6
y
Copyright © 2000 by Monica Yuskaitis
DefinitionDefinition Coordinates – an ordered pair of Coordinates – an ordered pair of
numbers that give the location of a numbers that give the location of a point on a grid. point on a grid. (3, 4)(3, 4)
12345
0
6
1 2 3 4 50 6
(3,4)
Copyright © 2000 by Monica Yuskaitis
HintHint The first number is always the x or first letter The first number is always the x or first letter
in the alphabet. The second number is always in the alphabet. The second number is always the y the second letter in the alphabet.the y the second letter in the alphabet.
1
32
45
0
6
1 2 3 4 50 6
(3,4)
Copyright © 2000 by Monica Yuskaitis
How to Plot Ordered PairsHow to Plot Ordered Pairs Step 1 – Always find the x value Step 1 – Always find the x value
first, moving horizontally either right first, moving horizontally either right (positive) or left (negative).(positive) or left (negative).
1
32
45
0
6
1 2 3 4 50 6
(2, 3)
y
x
Copyright © 2000 by Monica Yuskaitis
How to Plot Ordered PairsHow to Plot Ordered Pairs Step 2 – Starting from your new position Step 2 – Starting from your new position
find the y value by moving vertically find the y value by moving vertically either up (positive) or down (negative).either up (positive) or down (negative).
1
32
45
0
6
1 2 3 4 50 6
(2, 3)(2,3)y
x
Copyright © 2000 by Monica Yuskaitis
How to Find Ordered PairsHow to Find Ordered Pairs Step 1 – Find how far over horizontally Step 1 – Find how far over horizontally
the point is by counting to the right the point is by counting to the right (positive) or the left (negative).(positive) or the left (negative).
1
32
45
0
6
1 2 3 4 50 6
(5, )
y
x
Copyright © 2000 by Monica Yuskaitis
How to Find Ordered PairsHow to Find Ordered Pairs Step 2 – Now count how far Step 2 – Now count how far
vertically the point is by counting up vertically the point is by counting up (positive) or down (negative).(positive) or down (negative).
1
32
45
0
6
1 2 3 4 50 6
(5,4)
y
x
Copyright © 2000 by Monica Yuskaitis
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
Copyright © 2000 by Monica Yuskaitis
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
Copyright © 2000 by Monica Yuskaitis
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
Copyright © 2000 by Monica Yuskaitis
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
Copyright © 2000 by Monica Yuskaitis
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
Copyright © 2000 by Monica Yuskaitis
Four Quadrants of Coordinate GridFour Quadrants of Coordinate Grid When the number lines are extended into When the number lines are extended into
the negative number lines you add 3 more the negative number lines you add 3 more quadrants to the coordinate grid.quadrants to the coordinate grid.
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
y
x
Copyright © 2000 by Monica Yuskaitis
Four Quadrants of Coordinate GridFour Quadrants of Coordinate Grid If the x is negative you move to If the x is negative you move to
the left of the 0.the left of the 0.
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
x = -2y
x
Copyright © 2000 by Monica Yuskaitis
Four Quadrants of Coordinate GridFour Quadrants of Coordinate Grid If the y is negative you move If the y is negative you move
down below the zero.down below the zero.
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
y = -3y
x
Copyright © 2000 by Monica Yuskaitis
How to Plot in 4 QuadrantsHow to Plot in 4 Quadrants Step 1 - Plot the x number first Step 1 - Plot the x number first
moving to the left when the moving to the left when the number is negative. number is negative.
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
(-3, -2)(-3, -2)y
x
Copyright © 2000 by Monica Yuskaitis
How to Plot in 4 QuadrantsHow to Plot in 4 Quadrants Step 2 - Plot the y number Step 2 - Plot the y number
moving from your new position moving from your new position down 2 when the number is down 2 when the number is negative.negative.
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
(-3, -2)(-3, -2)
y
x
Copyright © 2000 by Monica Yuskaitis
How to Plot in 4 QuadrantsHow to Plot in 4 Quadrants When x is positive and y is When x is positive and y is
negative, plot the ordered pair in negative, plot the ordered pair in this manner.this manner.
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
(2, -2)(2, -2)
y
x
Copyright © 2000 by Monica Yuskaitis
How to Plot in 4 QuadrantsHow to Plot in 4 Quadrants When x is negative and y is When x is negative and y is
positive, plot the ordered pair in positive, plot the ordered pair in this manner.this manner.
-2
0-1
12
-3
3
-2 -1 0 1 2-3 3
(-2, 2)(-2, 2)
y
x
Copyright © 2000 by Monica Yuskaitis
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
Copyright © 2000 by Monica Yuskaitis
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
Copyright © 2000 by Monica Yuskaitis
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
Copyright © 2000 by Monica Yuskaitis
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
Copyright © 2000 by Monica Yuskaitis
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
Copyright © 2000 by Monica Yuskaitis
CreditsCredits
Clipart from “Microsoft Clip Gallery” located on the Internet at http://cgl.microsoft.com/clipgallerylive/default.asp