Websolid of revolution are the (cross sectional) disk method and the (layers) of shell method of integration. To apply these methods, it is easiest to: 1. Draw the plane region in question; 2. Identify the area that is to be revolved about the axis of revolution; 3. Determine the volume of either a disk-shaped slice or a cylindrical shell of the ... Web2. In order to apply the shell method, one must use a cross-section parallel with the axis of rotation. (a) If the cross-section is perpendicular with the xaxis, one must use the di erential dx. (b) If the cross-section is perpendicular with the yaxis, one must use the di erential dy. Disk method R b a ˇr 2(x)dxor R d c ˇr 2(y)dy Washer ...
Generalizing the washer method (video) Khan Academy
WebYou use the shell method when the axis you're rotating across is perpendicular to the axis you're integrating on. You use the disk/washer method when the axis you're rotating across is parallel to the axis you're integrating on. And if OP wants to understand why this is true, I strongly recommend drawing a typical slice of the region, and the ... Web(If you think about it, the washer method is just the disk method twice, but you subtract one disk from the other!) Anyhow, your intuition is more or less correct. The shell method asks for height of "cylinders" parallel to your axis of revolution: you're usually given the function in terms of y, so if you're revolving around y, that's easy. galaxy cat photo
Integration Example: Disk (Washer Method) vs. Shell Method
WebYou should use the disk when the region of integration goes all the way to the axis of rotation. Say you had the volume formed by rotating the region below y = 1 − x, above y = 0, and left of x = 0 around the y axis. Now the region touches the y axis, so you use a disk. – Ross Millikan Aug 23, 2013 at 19:21 Add a comment Webdisk/washer method, and (b) by the shell method. Show that the results are the same. 1. y =x2 2. y =x y =2x y =x3 For problems 3 - 4, let R be the region bounded by the given curves. Sketch R. If R is revolved about the y-axis, find the volume of the solid of revolution (a) by the disk/washer method, and (b) by the shell method. WebDisk Method is used when the representative rectangle produces a solid that is similar to a plate (no hole in the middle). The Washer Method is used when the rectangle sweeps … blackberry leap autoloader str100-1