Difference between revisions of "Directly Proportional"
(→About Direct Proportionality) |
|||
Line 9: | Line 9: | ||
: Two variables are said to be '''directly proportional''' when they always vary by the same ratio. | : Two variables are said to be '''directly proportional''' when they always vary by the same ratio. | ||
+ | ===Exam Marks=== | ||
+ | : Straight line [1] | ||
+ | : Passing through zero / the origin [1] | ||
===Examples=== | ===Examples=== | ||
{| class="wikitable" | {| class="wikitable" |
Revision as of 15:24, 5 December 2021
Contents
Key Stage 4
Meaning
When two variables are directly proportional when one variable is multiplied by a factor, the other variable is multiplied by the same factor.
About Direct Proportionality
- A scatter graph showing a directly proportional relationship has line with a linear gradient that passes through zero (it has a y-intercept of zero).
- On a proportional scatter graph when one variable doubles, the other doubles or when one triples the other triples.
- When two variables are directly proportional when any value for y is divided by its corresponding value for x it will always give a constant value.
- Two variables are said to be directly proportional when they always vary by the same ratio.
Exam Marks
- Straight line [1]
- Passing through zero / the origin [1]
Examples
This scatter graph shows a linear relationship that is directly proportional where x doubles, y doubles.
\(y = mx\) Where m, the gradient, is positive. |
References
AQA
- Directly proportional, pages 158-159, 282, GCSE Physics; Third Edition, Oxford University Press, AQA