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The Relationship Detective
📈 The Relationship Detective
Imagine you're a detective investigating the relationship between two things - like the cost of taxi rides and the distance travelled. You notice that every extra mile costs an extra £2, and there's a £3 starting fee. This creates a perfect straight line when graphed!
Straight line graphs show constant relationships and are everywhere in real life - from phone bills to speed calculations.
What is the y-intercept?: The point where the line crosses the y-axis, found when x = 0.
Mathematics glossary
- What is the y-intercept?
- The point where the line crosses the y-axis, found when x = 0.
- What is a linear relationship?
- A relationship where one variable changes at a constant rate with respect to another, producing a straight line graph.
Earn the mark scheme marks
💡 Exam Tips
- Use a ruler: Always draw straight lines with a ruler
- Extend lines: Draw lines across the full grid to show the complete relationship
- Label axes: Include units and scales on your axes
- Check with substitution: Verify your equation by substituting a point from the line
- Use sensible scales: Choose scales that make plotting easy and accurate
- Show working: When finding gradients, show the rise/run calculation clearly
Now try it yourself
Quiz · Question 1 of 14
A straight line has the equation y = 3x + 7. What is the gradient of this line?
Tap an answer to check it