Key Stage 4
Meaning
When a relationship between two variables is linear they increase by a constant amount in relation to one another.
About Linear Relationships
- A scatter graph showing a linear relationship has straight line of best fit.
- On a linear graph; when one variable increases, the other increase or when one increases the other decreases.
- A linear relationship may have a non-zero y-intercept.
- If the line of best fit on for a linear relationship has a y-intercept of zero then it is called 'directly proportional'.
Examples
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| This scatter graph shows a linear relationship where x increases and y increases.
\(y = mx + c\) Where m, the gradient, is positive. |
This scatter graph shows a linear relationship where x increases and y decreases.
\(y = mx + c\) Where m, the gradient, is negative. |
This scatter graph shows a linear relationship that is directly proportional where x doubles, y doubles.
\(y = mx\) Where m, the gradient, is positive. |