Your post borders upon asking for a tutorial and we are not a tutorial service.
If you will post a specific question telling us what you do not understand, then perhaps someone can help.
I'm currently taking a calculus 2 course and I don't really understand the differences between the disk method for finding the soild of revolution and the washer and shells methods. I gather that the shells method is easier when you are rotatating around the y axis and disk is better when rotating around the x axis. Washers seems to be good for when there will be a hole in the object that you are rotating. My problem is that I don't really know how to use these methods and have been stuck for hours now trying to apply them.
Thanks a lot.
Thanks for the quick replies. I have x-y^2=16, x=20 rotated about x=0. I set y^2 +16=20 and solved for the roots and got \pm2. I then integrated \pi x (y^2 +16)^2 dy. The correct answer is 5888\pi/15 and I have 18112\pi /15. Is my logic correct? I've checked and double checked my work and I can't find a mistake which leads me to believe that I'm doing something wrong in the setup.