My Math Forum  

Go Back   My Math Forum > College Math Forum > Calculus

Calculus Calculus Math Forum

LinkBack Thread Tools Display Modes
October 28th, 2014, 10:06 AM   #1
Joined: Oct 2014
From: England

Posts: 3
Thanks: 0

Calculating volume of hemisphere and surface area of hemisphere

When calculating the volume of a hemisphere, you can use discs of height dx and radius y. However, when calculating the surface area of a hemisphere you cannot use rings of height dx. Why is this?
john Cartwell is offline  
October 28th, 2014, 11:11 AM   #2
Math Team
Joined: Dec 2013
From: Colombia

Posts: 7,674
Thanks: 2654

Math Focus: Mainly analysis and algebra
That's a very good question.

As I understand it, it's because the error in the Riemann sum doesn't tend to zero (quickly enough) as $x \to 0$. This will be because the error in volume is of order $(\delta x)^2$ which goes to zero quicker than $\delta x$ which is the order of the error in curve length.
v8archie is offline  

  My Math Forum > College Math Forum > Calculus

area, calculating, hemisphere, surface, volume

Thread Tools
Display Modes

Similar Threads
Thread Thread Starter Forum Replies Last Post
Volume,area of surface? ricsi046 Real Analysis 3 April 28th, 2014 01:47 PM
Estimated Volume of a Solid Hemisphere jaredbeach Calculus 9 January 12th, 2012 08:49 PM
Surface area and volume winner Calculus 3 January 14th, 2011 11:30 AM
Centre of gravity in a hemisphere Algebra 2 March 19th, 2009 12:54 PM
Surface area and volume winner Algebra 2 December 31st, 1969 04:00 PM

Copyright © 2019 My Math Forum. All rights reserved.