Lesson video

Hi.

I'm Miss Davies.

In this lesson, we're going to be representing inequalities on coordinate grids.

If we were to represent x is greater than three on a number line, we would use a non-filled-in circle, and the arrow would be pointing to the numbers that are greater than three.

If we were to represent negative one is less than x which is less than or equal to three on a number line, we would put a non-filled-in circle on negative one and a filled-in circle on three.

We would then join these two circles together to show that x is a value between these two integers.

If we were to shade the region x is greater than three on a coordinate grid, we would draw a dashed line on x is equal to three.

We would then shade the region in which all x-coordinates were greater than three.

If we were to shade the region negative one is less than y which is less than or equal to three on a coordinate grid, we would draw a dashed line on y is equal to negative one and a solid line on y is equal to three.

We would then shade the region which has y-coordinates between negative one and three.

Here is a question for you to try.

Pause the video to complete your task, and resume once you're finished.

Here is the answer.

This is greater than or equal, so this needs to be represented by a solid line on x is equal to one.

Here is a question for you to try.

Pause the video to complete your task, and resume once you're finished.

Here is the answer.

Two is greater than y can be written as y is less than x.

This should be represented by a dashed line on y is equal to two.

Here is a question for you to try.

Pause the video to complete your task, and resume once you're finished.

Here is the answer.

This inequality requires solid lines on both x is equal to one and x is equal to three.

If we look at the shaded region on our coordinate grid, we can see that there is a solid line on x is equal to 0.

5.

There is also a dashed line on x is equal to three.

This means that x is greater than 0.

5, or it is equal to it.

We write this as 0.

5 is less than or equal to x, and x is also less than three.

This is the inequality that describes the shaded region.

Here is a question for you to try.

Pause the video to complete your task, and resume once you're finished.

Here is the answer.

This line is on x is equal to negative two, and it's a solid line.

So the inequality is x is greater than or equal to negative two.

Here is a question for you to try.

Pause the video to complete your task, and resume once you're finished.

He is the answer.

In this question, we've got a solid line on y is equal to three and a dashed line on y is equal to zero.

The inequality is therefore zero is less than y which is less than or equal to three.

Here is a question for you to try.

Pause the video to complete your task, and resume once you're finished.

Here is the answer.

In this question, we've got a dashed line on both y is equal to four and y is equal to negative one.

This means the inequality is negative one is less than y which is also less than four.

That's all for this lesson.

Thanks for watching.