## Functions and Their Graphs

Read this section for an introduction to functions and their graphs. Work through practice problems 1-5.

### Functions and Their Graphs

When you prepared for calculus, you learned to manipulate functions by adding, subtracting, multiplying and dividing them, as well as calculating functions of functions (composition).  In calculus, we will still be dealing with functions and their applications.  We will create new functions by operating on old ones.  We will derive information from the graphs of the functions and from the derived functions.  We will find ways to describe the point–by–point behavior of functions as well as their behavior  "close to"  some points and also over entire intervals.  We will find tangent lines to graphs of functions and areas between graphs of functions.  And, of course, we will see how these ideas can be used in a variety of fields.

This section and the next one are  a review of information and procedures you should already know about functions before we begin calculus.