1. Use of Maths Linear models Equations of straight lines Finding gradients

2. Aims Recap from lesson 1 Developing linear models The equation of a straight line

3. Recap

4. The equation of a straight line All straight lines have an equation of the form y = mx + c m is the gradient of the line c is the y-intercept Find the gradient and y-intercept for y= 4.8x - 6.9

5. Fill the gaps EquationGradienty-intercept y = 3x + 1 y = - 0.4x - 0.8 2.1-0.73 03.1 y = 6.2 y + x = 5.2

6. y = mx + c Re-arrange the following equations into the form y = mx + c and hence state the gradient and intercept with the y-axis 2x + y = 4 3x + y = -6 x + y = 7 2x + 2y = 6

7. Sketching lines Sketch the following straight line graphs y = 2x + 6 y = - x + 6 y = 6 x = 9

8. Sketching lines using mini-white boards

9. y = x

10. y = x + 2

11. y = 2x + 4

12. y = -2x + 1

13. y = 2.1

14. x = 3.2

15. Finding the gradient from the graph Gradient = distance up divided by the distance across Gradient = distance up distance across Gradient = rise run

16. Find the gradients of these lines

17. Booklet Ex 1