However, students often miss the point of the graph. Let me take a basic lab as an example. Suppose you have a cart that travels at a constant speed. ... That sort of looks linear, but it isn’t.

In order to draw the line graph we require several pairs of coordinates. These coordinates represent the relationship given in the equation. For example, for y = 3x , the y value is always equal ...

Bar charts and line graphs can be combined. Climate graphs are an example of this. The x-axis shows the months of the year and there are two y-axes to show average temperature and total rainfall.