Graphing on Four Quadrants

In This Lesson, We Will: Graph points on four quadrants and identify the signs of each quadrant.

Let’s look at coordinate planes: A coordinate plane is a grid with four sections. We designate the location of points with the coordinates.

A coordinate plane has two lines that divide the grid into four parts. Each line, or axis, is labeled with an x or y Each axis is a number line x How can you remember which is which? (Think of tails: Do tails usually hang down on animals like a horse? Which axis hangs down and which letter has a tail hanging down?) , y

Origin The intersection of the x-axis with the y-axis is called the origin. Why? The origin of anything is the “starting point”. It is the same on graphs. origin

An ordered pair is a combination of numbers that tells us where Ordered pairs: An ordered pair is a combination of numbers that tells us where to place a point on a coordinate plane. Ordered pairs are always given in the correct order! (Think of the alphabet: the x axis is always listed before the y axis.)

Think of a town as one big coordinate grid. If someone wanted to know where the closest intersection to your school is, what would you say? This is the same idea as an ordered pair. This gives the location of a certain point in your town!

This coordinate grid shows various locations in Washington D.C. Can you pick out any ordered pairs to designate location?

When you list an ordered pair, you should find the spot on the x-axis and the spot on the y-axis. Then simply move your fingers, one finger vertically and one horizontally, to the point where the two meet.

Another method would be to go to the left or right on the x-axis and then go up or down on the y-axis.

Vocabulary to Understand Coordinate - the numbers that tell the distance and direction of a point from the origin. Origin - the intersection of the x axis and y axis. Quadrant - a section of a coordinate plane.

Let’s try it! (5,4) (-4,7) (-3,-1) (3, -4) First make a coordinate plane on your Webquest answer sheet. Now plot the following points: (2,2) (-1,6) (-5,-3) (2, -2) (5,4) (-4,7) (-3,-1) (3, -4)

Your coordinate grid should look similar to this: (-4,7) (-1,6) 5 (5,4) 4 3 (2,2) 2 1 -1 -6 -5 -4 -3 -2 -1 1 2 3 4 5 6 -2 (-3,-1) -3 (2, -2) -4 (3, -4) (-5,-3) -5 -6 -7

Do you see any pattern? -6 -5 -4 -3 -2 -1 1 2 3 4 5 6 (-4,7) (-1,6) 5 (5,4) 4 3 (2,2) 2 1 -1 -6 -5 -4 -3 -2 -1 1 2 3 4 5 6 -2 (-3,-1) -3 (2, -2) -4 (3, -4) (-5,-3) -5 -6 -7 Do you notice anything about the signs of the numbers in each section of the graph?

Each section, or quadrant, of the grid has a Roman numeral assigned to it: II I 5 4 3 2 1 -1 -6 -5 -4 -3 -2 -1 1 2 3 4 5 6 -2 -3 -4 -5 -6 IV III -7

What are the signs for each x and each y in the designated quadrant? (-4,7) (-1,6) Look at the graph again: 5 (5,4) 4 3 (2,2) 2 1 -1 -6 -5 -4 -3 -2 -1 1 2 3 4 5 6 -2 (-3,-1) -3 (2, -2) -4 (3, -4) (-5,-3) -5 -6 -7

II I (+,+) (-,+) III IV (-,-) (+,-) In this way, we always know what section of the coordinate plane an ordered pair will be found! II I 5 4 (+,+) (-,+) 3 2 1 -1 -6 -5 -4 -3 -2 -1 1 2 3 4 5 6 -2 -3 -4 -5 III -6 IV -7 (-,-) (+,-)

What section will each of the following be found? (62,52) (-21,6) (-85,-43) (2, -2) (75,74) (-41,7) (-33,61) (-83, -4) Draw a coordinate plane then write each ordered pair in the correct quadrant on your webquest answer sheet. (Note: you do not have to plot the points!)

Find the ordered pairs for each of the following points on the graph: 5 D E 4 3 2 C 1 -1 -6 -5 -4 -3 -2 -1 1 2 3 4 5 6 -2 -3 G -4 B -5 -6 H -7 A

We have learned the vocabulary below: Number line Coordinate Coordinate plane Quadrants Ordered pair Points Origin x-axis y-axis

You have done a great job today! If you need to review this information again feel free to go through this presentation as many times as you need!

Written by: J. S. Liberatore Coordinate planes Written by: J. S. Liberatore