Cartesian Coordinates Working with Ordered Pairs Cartesian Coordinates

Cartesian Coordinates • Cartesian coordinates can be used to pinpoint where you are on

Using Cartesian Coordinates you mark a point on a graph by how far along

X and Y Axis The left-right (horizontal) direction is commonly called X. The up-down

Where they cross over is the "0" point, you measure everything from there. The

Example: Point (6, 4) is 6 units along (in the x direction), and 4

• Like 2 Number Lines Put Together • It is like we put

Writing Coordinates • The coordinates are always written in a certain order: the horizontal

• The Origin • The point (0, 0) is given the special name

• "Cartesian". . . ? • They are called Cartesian because the idea

• What About Negative Values of X and Y? • Just like with

So, for a negative number: go backwards for x go down for y For

Slides: 12

Download presentation

Cartesian Co-ordinates Working with Ordered Pairs

Cartesian Coordinates • Cartesian coordinates can be used to pinpoint where you are on a map or graph.

Using Cartesian Coordinates you mark a point on a graph by how far along and how far up it is: The point (12, 5) is 12 units along, and 5 units up.

X and Y Axis The left-right (horizontal) direction is commonly called X. The up-down (vertical) direction is commonly called Y. Put them together on a graph. . . and you are ready to go!

Where they cross over is the "0" point, you measure everything from there. The X Axis runs horizontally through zero The Y Axis runs vertically through zero Axis: The reference line from which distances are measured. The plural of Axis is Axes, and is pronounced ax-eez And you can remember which is which by: x is A CROSS, so x is ACROSS the page.

Example: Point (6, 4) is 6 units along (in the x direction), and 4 units up (in the y direction) So (6, 4) means: Go along 6 and then go up 4 then "plot the dot".

• Like 2 Number Lines Put Together • It is like we put two Number Lines together, one going left-right, and the other going updown.

Writing Coordinates • The coordinates are always written in a certain order: the horizontal distance first, then the vertical distance. • This is called an "ordered pair" (a pair of numbers in a special order) • And usually the numbers are separated by a comma, and parentheses are put around the whole thing like this: (3, 2) • Example: (3, 2) means 3 units to the right, and 2 units up • Example: (0, 5) means 0 units to the right, and 5 units up.

• The Origin • The point (0, 0) is given the special name "The Origin", and is sometimes given the letter "O".

• "Cartesian". . . ? • They are called Cartesian because the idea was developed by the mathematician and philosopher Rene Descartes who was also known as Cartesius. • He is also famous for saying "I think, therefore I am".

• What About Negative Values of X and Y? • Just like with the Number Line, you can also have negative values. • Negative: start at zero and head in the opposite direction: • Negative x goes to the left • Negative y goes down

So, for a negative number: go backwards for x go down for y For example (-6, 4) means: go back along the x axis 6 then go up 4. And (-6, -4) means: go back along the x axis 6 then go down 4.