# Functions Topics

## Functions explanations, examples, practice problems. Ready? Let’s do this.

#### Sets, Functions, and Relations

"Sets, relations, and functions" doesn't have quite the same ring as "lions, tigers, and bears" (oh my!), but they can seem equally intimidating at times. Except for the fact that they're math c...

#### Graphing

A graph is a type of picture that we can use to visualize ordered pairs, relations, and functions. Rather than force you to imagine what they might look like, we'll use actual, physical diagrams...

#### Linear Functions and Equations

A linear function is a function whose graph is a straight line. The line can't be vertical, since then we wouldn't have a function, but any other sort of straight line is fine. Now, are you ready t...

#### Writing Linear Equations

If we know the intercepts and the slope of a linear equation, we know everything there is to know about it. Sure, we may not know where it was born, who its favorite musical artist is, or its sta...

#### Nonlinear Functions

Some functions are less expressive than others. We're not trying to be judgey, here: it's true. For example, take the graph of a linear function. (We like x = 4; there's a lot of history there.)...

#### In the Real World

Graphs are useful because many people prefer looking at pictures to looking at equations. They're not necessarily better, though. While a picture may be worth a thousand words, it's really only w...