Question

Write a rule for the linear function in the graph

Answer 1

Gradient = $\frac{y_{1}-y_{2}}{x_{1}-x_{2}}$

$\frac{5-1}{2-1} \\\frac{4}{1}$

This means the gradient is 4x.

The y intercept is where the line crosses the y axis. We can see this is at -3.

Rule: y = 4x -3

Substitute your values to check if it's right.

y = 4x -3

5 = 4(2) - 3

5 = 8 - 3

5 = 5

1 = 4(1) - 3

1 = 4 - 3

1 = 1