A short YouTube lesson by Paul (Third Space Learning) introducing straight line graphs (linear functions). It defines the form y = mx + c, explains m (gradient) and c (y-intercept), shows how to calculate gradient from two points, gives a worked example producing y = 2x + 1, demonstrates plotting via substitution and a faster point-generation method using the gradient, and ends with links to further resources and calls-to-action.
Chapters
Hi, this is Paul from Thirds Based Learning. Let's have a look at straight line graphs. Remember, you can access loads of free resources and get information on our one to one tuition over at thirdspacelearning.com straight line graphs are a visual representation of a linear function. They have the form Y mx C. M is the gradient of a line. It tells us how the graph changes over time, its steepness and C is the Y intercept, which is where it crosses the y axis. So for example, this straight line has the general form Y mx C. Let's work out the gradient by selecting two points on the graph, then working out the difference in the y values, working out the difference in the x values and dividing them. So here M the gradient is 2. Next, let's work out C. Now C is the Y intercept which is where it crosses the y axis. And we can see that it crosses the y axis at positive 1. So c is positive 1. So the general form of this graph is y equals 2x1. We can plot straight line graphs by substituting in values for X to work out the y values. So When X is 0, Y is 1. When X is 1, Y is 3. When X is 2, Y is 5. And we can keep on doing that. But a really quick way to do this is to notice that the gradient is 2. So all we have to do is add on 2 to the y values and we can keep on doing that to work out our straight line graph. Once we have a few points, we can join them up with a lovely straight line that passes through all the points. And there we have it. Straight line graphs. Now over to you. Check out the links in the description below for step by step examples, questions, worksheets and tons of free resources to help you practice. You'll also find information on our one to one personalised maths tuition. Don't forget to like and subscribe to Stay up to date with all the latest Thursday learning videos.
