Thread: volumes of revolution

Hello,

I perfectly understand both methods (discs and shells) my only problem is to know which one to use.


Let's say I had a problem it would be hard fo me to know which method to use... and would both work each time?


Thank you

It's more a matter of convenience. There's not a function I can think of that you couldn't weasle through with either method. A torus is a common example where shells are a little more stright forward. This is a good example where washer would be preferred.

Ok thaks so much, so basically both methods work each time but you could have a method which is easier to use!

Originally Posted by thehabsonice

Ok thaks so much, so basically both methods work each time but you could have a method which is easier to use!

Usually one method has easier integrations and/or one integral opposed to two integrals. Case in point revolve the region bound by

about the -axis

Shells:
Washers