An important part of understanding functions is understanding their domain and range. Domain and range are all the possible x-values and y-values of the function, and can often be described easily by looking at a graph. In order to grasp domain and range, students must understand how to determine if a relation is a function and interpreting graphs.
The ideas of domain and range are some of the most important math ideas that to see in your upcoming math classes.
It's really important that you guys start thinking about domain as the set of all possible X values or input values and the range as a set of all possible Y values or output values.
And you want to be able to find the domain and range not only from like a set of points but also to be able to find the domain and range from a graph where it might just be like a little splattering of points.
Domain and range show up in lots of different places and that's why it's important that you keep those two ideas straight in your head.