GraphsTopic Summary
Topic Summary: Linear Graphs Problems
Part of Linear Graphs Problems — GCSE Mathematics
This topic summary covers Topic Summary: Linear Graphs Problems within Linear Graphs Problems for GCSE Mathematics. Revise Linear Graphs Problems in Graphs for GCSE Mathematics with 16 exam-style questions and 11 flashcards. This topic appears less often, but it can still be a useful differentiator on mixed-topic papers. It is section 10 of 10 in this topic. Use this topic summary to connect the idea to the wider topic before moving on to questions and flashcards.
Topic position
Section 10 of 10
Practice
16 questions
Recall
11 flashcards
Topic Summary: Linear Graphs Problems
Key Formula
- y = mx + c
- m = (y₂ − y₁) ÷ (x₂ − x₁)
- Gradient = rate of change
- y-intercept = starting/fixed value
Finding the Equation
- From graph: read c, calculate m from two points
- From two points: calculate m first, then substitute to find c
- Always verify by checking both original points
- Simultaneous equations: find crossing point of two lines
Key Vocabulary
- Gradient: rate of change (rise ÷ run)
- y-intercept: starting value (fixed charge)
- Simultaneous: two equations solved at the same time
- Interpolation: predicting within the data range
- Extrapolation: predicting outside the data range
Common Errors
- Confusing y-intercept (crosses y-axis) with x-intercept
- Not including units with gradient in context questions
- Assuming extrapolation is reliable
- Not checking final equation against original points