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# Plotting an inequality example

Learn how to plot a simple inequality on a number line. The example used in this video is x < 4. Created by Sal Khan and Monterey Institute for Technology and Education.

Video transcript

Graph x is less than 4. So let's draw ourselves
a number line over here. So let me draw a number line. I'll start here at 0,
so 0, 1, 2, 3, 4, 5. And we could go below 0. We'd have negative 1, negative
2, negative 3, negative 4. I could keep going. Now, we want to graph all of
the x's that are less than 4, but we're not including 4. It's not less than
or equal to 4. It's just less than 4. And to show that we're not
going to include 4, what we're going to do is we're going
to draw a circle around 4. So this shows us that
we're not including 4. If we were including 4, I
would make that a solid dot. And to show that we're going to
do all the values less than 4, we want to shade
in the number line below 4, going down
from 4, just like that. And then we can just shade
in the arrow just like that. So this right here is all
of the values less than 4. And you could test it out. Take any value
where there's blue. So there's blue over
here, negative 2. Negative 2 is
definitely less than 4. If you take this value
right here, this 2, it's definitely less than 4. 4 is not included because
4 is not less than 4. It's equal to 4. 5 is not included because
5 is not less than 4.