Coordinate Geometry You should know what these mean and be able to use them: Coordinates Ordered pairs X axis Y axis
Start with a number line: 0  1  2  3  4  5  6  7  8  9  10 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1
Add a vertical number line: 9 8 7 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 -7
The horizontal number line is called the “ x axis ” |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | -10 -9 -8 -7 -6 -5 -4 -3 -2 -1  0  1  2  3  4  5  6  7  8  9  10
The vertical number line is called the “ y axis ” 7 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- (I remember y is for the up and down axis because the y stretches down.)
Put them together! |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  | -10  -9  -8  -7  -6  -5  -4  -3  -2  -1  0  1  2  3  4  5  6  7  8  9  10 --4 --3 --2 --1 -- -1 -- -2 -- -3 -- -4 -- -5
Where the two meet is called the “ origin ” That is zero on both scales. 0
It’s easier to find where you are if you put this on a grid: -10  -9  -8  -7  -6  -5  -4  -3  -2  -1  0  1  2  3  4  5  6  7  8  9  10 7 6 5 4 3 2 1 -1 -2 -3 -4 -5 -6 -7 y x
Coordinates   are the points on the grid: 2, 5 1, 3 3, 7 and so forth
We put the point at the coordinates--Start with X, then Y -10  -9  -8  -7  -6  -5  -4  -3  -2  -1  0  1  2  3  4  5  6  7  8  9  10 7 6 5 4 3 2 1 --  -1 --  -2 --  -3 --  -4 --  -5 --  -6 --  -7 y x For  example for  2,5 Go to 2 on the x axis first. Then go to 5 on the y axis. Here is the point defined as 2,5
The two coordinates come in pairs to tell you the point on the grid. They are an ordered pair. What’s the  order? Which is first, x or y?
How do I remember which comes first, x or y? a b c d e f g h i j k l m n o p q r s t u v w  x   y  z When you say or write the alphabet   x comes before y
You can also think of running before you climb up or down

Coordinates

  • 1.
    Coordinate Geometry Youshould know what these mean and be able to use them: Coordinates Ordered pairs X axis Y axis
  • 2.
    Start with anumber line: 0 1 2 3 4 5 6 7 8 9 10 -10 -9 -8 -7 -6 -5 -4 -3 -2 -1
  • 3.
    Add a verticalnumber line: 9 8 7 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -6 -7
  • 4.
    The horizontal numberline is called the “ x axis ” | | | | | | | | | | | | | | | | | | | | | -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10
  • 5.
    The vertical numberline is called the “ y axis ” 7 6 5 4 3 2 1 0 -1 -2 -3 -4 -5 -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- (I remember y is for the up and down axis because the y stretches down.)
  • 6.
    Put them together!| | | | | | | | | | | | | | | | | | | | | -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 --4 --3 --2 --1 -- -1 -- -2 -- -3 -- -4 -- -5
  • 7.
    Where the twomeet is called the “ origin ” That is zero on both scales. 0
  • 8.
    It’s easier tofind where you are if you put this on a grid: -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 7 6 5 4 3 2 1 -1 -2 -3 -4 -5 -6 -7 y x
  • 9.
    Coordinates are the points on the grid: 2, 5 1, 3 3, 7 and so forth
  • 10.
    We put thepoint at the coordinates--Start with X, then Y -10 -9 -8 -7 -6 -5 -4 -3 -2 -1 0 1 2 3 4 5 6 7 8 9 10 7 6 5 4 3 2 1 -- -1 -- -2 -- -3 -- -4 -- -5 -- -6 -- -7 y x For example for 2,5 Go to 2 on the x axis first. Then go to 5 on the y axis. Here is the point defined as 2,5
  • 11.
    The two coordinatescome in pairs to tell you the point on the grid. They are an ordered pair. What’s the order? Which is first, x or y?
  • 12.
    How do Iremember which comes first, x or y? a b c d e f g h i j k l m n o p q r s t u v w x y z When you say or write the alphabet x comes before y
  • 13.
    You can alsothink of running before you climb up or down