How to plot straight line graphs
Home learning focus
Learn how to plot straight line graphs.
This lesson includes:
- one video
- learning summary
- one activity sheet
For students looking to achieve grade 4 in GCSE Maths, students must know that a linear equation is drawn as a straight line on a set of axes. A table of values can be used to plot straight line graphs.
Check your understanding of how to draw a graph of a linear equation by watching this short video from BBC Bitesize, KS3 Maths.
How to draw a graph of a linear equation
A linear equation can be represented as a line graph. In order to draw the line graph we require several pairs of coordinates. These coordinates represent the relationship given in the equation.
For example, for y = 3x, the y value is always equal to '3 lots' of the x value. (1,3), (10,30) and (2.5,7.5) are all coordinates on the line y = 3x.
Often a table of values is used to create the coordinates. We use substitution to calculate the values.
For example: y = 2x + 1
The y value is always '2 lots' of the x value plus 1.
We replace the value of x for different numbers and record the resulting y value.
An example of how to plot a straight line graph
Draw the graph of the equation y = 3x - 1.
Create a table of values to find the coordinates on the graph:
Plotting the coordinates and drawing a line through them on a graph looks like this:
Choose your exam specification
BBC Bitesize has GCSE exam board-relevant content for students in England, Northern Ireland and Wales. Chose the exam specification that matches the one you study.
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