This week, I learnt how to spot the difference between a function and a normal relation. This is fairly easy to do once you understand the basic concept.

A function is a relation that has no repeating X value. This can be shown in graphs, charts, etc.

Here are a few examples of functions:

These are functions as the X value is never there twice. A couple examples of graphs and charts that aren’t functions are:

This is because in the first chart, 3 has 2 values, 5 and 7.

In the second chart, the line curves back on itself so all x values under 15 have 2 y values.