The Disk Method - Calculus 2

Another application of definite integrals is the ability to calculate the volume of solids with known cross sections. The first type of solid we will look at is a solid of revolution, or a solid with circular cross sections.

Solids of revolution are formed by revolving an enclosed region around an axis. This axis can be horizontal or vertical, and the overall shape of the solid is dependent on which of these two types of axis of revolution is chosen.

One method of calculating the volume of these solids of revolution is to use what is known as the disk method, which calculates the volume by adding up the volume of an infinite number of thin disks that would make up the solid.

The disk method is sort of like slicing a tomato. Each disk-shaped slice of the tomato has its own volume, but add the volume of all the slices together, and you have the volume of the entire tomato!

But enough about tomatoes, let's take a look at what this lesson of Calculus 2 is all about.

In this lesson, you will learn:

• What solids of revolution are and how to find their volume with definite integrals via the disk method
• How to use the disk method to calculate volume of solids of revolution formed by revolving a region around the x-axis
• How to use the disk method to calculate volume of solids of revolution formed by revolving a region around the y-axis

I hope you find this video to be helpful!

-Josh