# Week 10 – Math 10

This week in math 10, we started a new concept on functions. They fall similiar to relations in that they are a type of relation. You can tell the difference between a function and a relation by looking at a graph. For linear relations, the equation forms a straight line and every x value (input), has only one y value (output). This is an example of a function. But in other cases a relation forms lines on a graph that are weird looking. They could be curved, zigzag or a full circle. In these cases, some x values (input) have more than 1 y value (output).

There is an even easier way to recognize relations and functions. Imagine you have a vertical line and you are doing a scan of the graph. If the line that you are using passes points on a graph one at a time, it is a function. But if the line passes more than one paint on a graph at the same time, it is a relation.

This relation below is a function because the vertical line passes through each point one at a time.  This graph below is a relation because the vertical line passes through 2 points at a time.   