This video describes patterns in non linear functions and how they sometimes appear on the graph. Non – linear functions do not increase/decrease at a constant rate. This means that the rate of change can vary at different points on the grid. Instead of appearing as a straight line on a graph, it can follow different sorts of paths, yet still be a function.
This raises the question of how to determine whether a graph is a function or not. All functions on a graph must pass what is known as a vertical line test, where a single x-value cannot have 2 y-values, otherwise, it is not a function.