If you understand the definition of a mathematical function, a good way to judge it is that any line drawn parallel to the y-axis intersects with the values in the function’s curve only once. The same ...

Pie charts show percentages as a circle, divided into segments. A pie chart could be used to show how students travel to school. Each piece of data is shown as a proportion of 360, because there are ...

In geography it is important to be able to read and understand data that is presented in a range of different ways. We often use graphs to present data in a clear and accessible way. There are many ...