Your calculator can do an excellent job of graphing functions. We will learn how in a few lectures. The reason for this is that your calculator just loves to plot points (x,y) and connect them with lines. So let's try to think of a graph this way.

The graph of a function y = f(x) is all the points (x,y) where when you find f(x) you get y.

It is important to note that the graph of a function and the function itself give the same information, just differently. Please make sure that you can read a graph of a function. That is if I give you a value of x you can tell me what f(x) is from the graph.

Now a function is nice to graph, as for each x there is only one y to be found. This is summarized in the vertical line test for functions which says functions must intersect vertical lines at most once. (It might miss altogether)

This section introduces some language that becomes important in a calculus class: increasing-, decreasing-, even- and odd functions. The first two are clear from the graph, the last two deal with how a graph is symmetric. Please make sure you understand what we mean by the graph is symmetric, If not speak up.