This allows you to find the y-intercept, or the point at which the line intersects the graph's vertical axis.

The gradient shows the cost per litre. Petrol costs £1.15 per litre. The graph crosses the vertical axis at (0, 0). This is known as the intercept. It shows that if you buy 0 litres, it will cost ...

The intercept (where the graph crosses the vertical axis) is the cost when there are zero guests. This is the charge for hiring the room and is equal to £350. Question Find the gradient of the graph.