# Surface Area Formula Demonstration

- Author:
- Ravinder Kumar

Main purpose of this applet is to demonstrate how surface area of revolution about x-axis is made up of surface areas of infinitesimal cylinders with height equal to length of infinitesimal arc length ds and radius equal to vertical position of ds.
For more on surface area of revolution check my online book
"Flipped Classroom Calculus of Single Variable"
https://versal.com/learn/vh45au/