This deep dive covers Method: Finding the Constant within Proportion Graphs for GCSE Mathematics. Revise Proportion Graphs in Ratio & Proportion for GCSE Mathematics with 14 exam-style questions and 4 flashcards. Use this page as part of a wider topic revision path rather than treating it as an isolated fact. It is section 3 of 6 in this topic. Use this deep dive to connect the idea to the wider topic before moving on to questions and flashcards.
Method: Finding the Constant
1
Write the equation: y = kx (or y = kx² for Higher)
2
Substitute given values to find k
3
Rewrite formula with the k value
4
Use your formula to find missing values
Practice questions for Proportion Graphs
Which of the following describes the graph of a direct proportion relationship?
Aisha says: 'Because the graph of y against x is a straight line, y must be directly proportional to x.' Is Aisha correct? Explain your answer.
Quick recall flashcards
Finding k
Use given values to find constant k, then apply to new values
Direct vs Inverse
Direct: both increase together (y ∝ x). Inverse: one increases, other decreases (y ∝ 1/x).