coordinate geometry by monica yuskaitis. copyright © 2000 by monica yuskaitis definition grid – a...

Coordinate Geometry

by Monica Yuskaitis

Copyright © 2000 by Monica Yuskaitis

Definition Grid – A pattern of horizontal and

vertical lines, usually forming squares.


Definition Coordinate grid – a grid used to

locate a point by its distances from 2 intersecting straight lines.

ABCDE

1 2 3 4 5

What are the coordinates

for the house?


Definition x axis – a horizontal number line

on a coordinate grid.

1 2 3 4 50 6 x


Hint x is the shortest and likes to lie

down horizontally.

1 2 3 4 50 6 x


Definition y axis – a vertical number line on

a coordinate grid.

12345

0

6

y


Hint y is the tallest and stands upright or

vertically.

12345

0

6

y


Definition 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)


Hint 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 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 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 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, )

y

x


How 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?

1

32

45

0

6

1 2 3 4 50 6

(3,5)

y

x



1

32

45

0

6

1 2 3 4 50 6

(2,6)

y

x



1

32

45

0

6

1 2 3 4 50 6

(4,0)

y

x



1

32

45

0

6

1 2 3 4 50 6

(0,5)

y

x



1

32

45

0

6

1 2 3 4 50 6

(1,1)

y

x


Four Quadrants of Coordinate GridWhen 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 of Coordinate 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 of Coordinate 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 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)y

x


How 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)

y

x


How 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)

y

x


How 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)

y

x


Plot This Ordered Pair

-2

0-1

12

-3

3

-2 -1 0 1 2-3 3

(-3, -3)

y

x



-2

0-1

12

-3

3

-2 -1 0 1 2-3 3

(-1, 2)

y

x



-2

0-1

12

-3

3

-2 -1 0 1 2-3 3

(1, -1)

y

x



-2

0-1

12

-3

3

-2 -1 0 1 2-3 3

(2, -2)

y

x



-2

0-1

12

-3

3

-2 -1 0 1 2-3 3

(-3, -2)

y

x


Credits

Clipart from “Microsoft Clip Gallery” located on the Internet at http://cgl.microsoft.com/clipgallerylive/default.asp

http://cgl.microsoft.com/

coordinate geometry by monica yuskaitis. copyright © 2000 by monica yuskaitis definition grid – a...

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