# Differential Equations

Differential equations are a special type of integration problem.

Here is a simple differential equation of the type that we met earlier in the Integration chapter:

(dy)/(dx)=x^2-3

We didn't call it a differential equation before, but it is one. We'll see several different types of differential equations in this chapter.

### Why are we doing this?

There are many applications of differential equations, including:

## In this Differential Equations Chapter

In this chapter we will learn about:

### Second Order Differential Equations

Before we see how to solve differential equations, let's see an example of them in action in the AIDS example.