My Math Forum Using the washer/shell/disk when solving in terms of y.

 Calculus Calculus Math Forum

 March 8th, 2009, 11:55 AM #1 Newbie   Joined: Mar 2009 Posts: 5 Thanks: 0 Using the washer/shell/disk when solving in terms of y. I have an exam in two days and we got our practice exam. He put something on there that always throws me off! I am a very visual person and when I do problems with the washer/shell/disk integration, I always graph what I have before solving. When I get a problem that is in terms of y, I always get thrown since I can't really graph it. My question is, what are YOUR steps (simple please) in solving a problem like this one: x = y^2+1 and x = 5 set up an integral for the volume of the solid if it's rotated around x = -1. Any way to graph using my calculator in terms of y? I guess that's what is throwing me off. Thanks!
 March 8th, 2009, 01:11 PM #2 Guest   Joined: Posts: n/a Thanks: Re: Using the washer/shell/disk when solving in terms of y. You can use washers or shells. When we use shells, the cross sections are parallel to the axis about which we are revolving. Since we are revolving about x=-1, the cross sections will be 'stacked up' along the x-axis. Solve your equation for y in terms of x. $y=\pm\sqrt{x-1}$ Shells: $2{\pi}\int_{1}^{5}(x+1)\sqrt{x-1}dx$

 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post brsystem Calculus 4 September 16th, 2012 09:20 PM Messerschmitt Algebra 3 September 1st, 2012 08:35 AM Obsessed_Math Calculus 4 July 6th, 2012 10:36 PM hackedx Calculus 1 February 13th, 2011 07:03 PM cluelessengineer Abstract Algebra 1 March 9th, 2010 03:40 PM

 Contact - Home - Forums - Cryptocurrency Forum - Top