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### Course: Algebra basics > Unit 4

Lesson 1: Coordinate plane# Points and quadrants example

Plotting points on a graph involves moving along the x and y axes. Positive x-values move right, negative x-values move left. Positive y-values move up, negative y-values move down. The graph is divided into four quadrants, helping us locate points easily. Created by Sal Khan.

## Want to join the conversation?

- Hello everyone! Please don’t be disrespectful to those who don’t know something! That’s why these comments exist, Instead of making fun of them for not knowing the answer: Help the, understand how you do. To anyone who has received harmful answers, Don’t be discouraged, They are learning something too you are very smart and keep trying!(33 votes)
- Why do they have axases?(10 votes)
- The axis are to plot points. You can't plot without an "address", and since coordinate planes are theoretically infinite, there needs to be something to define where a point is. The axis is kind of like a street in a city then the points are the different houses, if that analogy makes sense.

Did this help answer your question?(13 votes)

- quadrants are numbered in counterclockwise order starting at the upper right quadrant, how would octants be numbered? starting where and what order?(10 votes)
- You name the axis that it is on instead of the quadrant. (0,0) is on the origin(0 votes)

- In which quadrant does (0,0) lies?(4 votes)
- The point (0,0) doesn't lie in a specific quadrant. This is because it's essentially where the two axes (x and y) meet; the boundary between all 4 quadrants. It's known as the origin, and not really defined as belonging to any of the quadrants on a coordinate plane.(11 votes)

- Could someone help me? I have been stuck on graphing for awhile and my teacher wants me to redo my test because of it. Does anyone know some ways I got possibly remember?(7 votes)
- Under the assumption that your problem is remembering the quadrant locations, a simple way you can remember the quadrants is by imagining how you write a "c". Specifically, the order of all the quadrants goes as top right, top left, bottom left, bottom right. That's also the way you write a "c".(3 votes)

- In which quadrant does the point (0,1) lie?(1 vote)
- Points that lie directly on the x and y axis aren't considered to be in a quadrant. In this case, you would just say that the point (0, 1) lies on the y-axis(10 votes)

- how do you remember which quadrant is wich(3 votes)
- so the way I remember it is to make the letter C in the graph(4 votes)

- What exactly is a quadrant?(0 votes)
- A quadrant is four parts of a plane, sphere, space, or body divided by two lines or planes at right angles.(14 votes)

- Just to ask, is it a necessity to say "comma" in between numbers? because I think it's just [7,7] is read "7 by 7."(4 votes)
- Why are the quadrants designated as such? Is there any particular reason? Thank You.(2 votes)
- It's just a convention, I believe. Some other places have different orders for their quadrants, though I think the regular order (shown by Sal) is in the order you encounter them as directional angles increase.
*Hope this helps :D*(4 votes)

## Video transcript

Plot 4 comma negative
1, and select the quadrant in
which the point lies. So 4, the first
number in our ordered pair, that's our x-coordinate. That says how far to move in the
horizontal or the x-direction. It's a positive 4. So I'm going to
go 4 to the right. And then the second
coordinate says, what do we do in the
vertical direction or in the y-direction? It's a negative 1. Since it's negative,
we're going to go down. And it's a negative 1, so
we're going to go down 1. So that right over there is
the point 4 comma negative 1. So I've plotted
it, but now I have to select which quadrant
the point lies in. And this is just a
naming convention. This is the first quadrant. This is the second quadrant. This is the third quadrant. And this is the fourth quadrant. So the point lies in the
fourth quadrant, quadrant IV. And I guess you have to
know your Roman numerals a little bit to know that's
representing quadrant IV. Let's do a couple more of these. Plot 8 comma negative
4, and select the quadrant in
which the point lies. Well, my x-coordinate
is 8 so I go 8 in the positive x-direction. And then my y-coordinate is
negative 4, so I go 4 down. And this is sitting,
again, in not the first, not the second, not the third,
but the fourth quadrant, in quadrant IV. Let's do one more of these. Hopefully we get a
different quadrant. So we want to plot the
point negative 5 comma 5. So now my x-coordinate
is negative. It's negative 5. So I'm going to move to the
left in the x-direction. So I go to negative 5. And my y-coordinate
is positive so I go up 5, so negative 5 comma 5. And this is sitting not
in the first quadrant, but the second quadrant. And of course, this is
the third and the fourth. So this is sitting in
the second quadrant. Check answer, and
we got it right.