Lesson video

Hi, I'm Miss Davies.

In this lesson, we're going to be drawing and recognising graphs that are in the form y equals kx, where k is a constant.

In which pairs of coordinates is the y-value equal to the x-value? Four, four, negative nine, negative nine, zero, zero.

Hence, which of these points lie on the line y equals x? It's these three pairs of coordinates.

We're going to plot the graph y equals x.

We've been given six x-coordinates.

The y-coordinates for this graph are the same as the x-coordinates.

These are the coordinates that we're going to plot, starting with negative two, negative two, then all the way up.

We're then going to join these points with a straight line.

The line should run across the whole length of the grid that you have been given.

In which pairs of coordinates is the y-value double the x-value? Negative seven, negative 14, 0.

3, 0.

6 and zero zero.

Which of the points above lie on the line y equals two x? These are the three points that lie on this line.

Next, we're going to plot the graph of y is equal to two x.

Again, we've been given six x-coordinates.

We need to calculate the y-coordinates.

To work out these y-coordinates, we're going to double all of our x-values.

These are the coordinates that we're going to plot.

Then I going to draw a line that joins all of these points.

Here are some questions for you to try.

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

Here are the answers.

The gradient of this line should have been four.

This means that for every one unit it moves to the right, it goes four units up.

Here are some questions for you to try.

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

Here are the answers.

The gradient of this line should have been negative one.

This means that for every one unit it moves it to right, it moves one unit down.

That's all for this lesson.

Thanks for watching.