revolving a region in the first quadrant bounded by the graphs of y x2 and about the y-axis First. Prerequisites: Students should be familiar with areas of planar regions

using approximations by Riemann sums and limits that lead to the definite integral. . Before indulging, it is easy for students to hold the candy and think about how one could compute the volume of the candy by imagining that the candy is a disk and then subtracting the "hole.". Approximating half-washers are drawn. An example from the Visual Calculus collection is available at lculus/5/ml. Rate this Solution, rating : (Lowest) (highest feedback : Submit Your Questions Here! By allowing the thickness of each washer to become very small and summing up the volumes, we volume by disks/washers homework solutions obtain the definite integral representation for the washer method. V _ V _ V _ m - 177 - Stu Schwartz. Figure 6 displays a cake washer and a cake shell. . M -176 -Stu Schwartz Volume by Disks/Washers -Homework. Volume of slice y2 dx. V _ V _ V _ d) the y-axis e) the line x 4 f) the line. Classroom Activities: An informative discussion about using props as teaching aids is in Carol Critchlow's paper 'A prop is worth ten thousand words Mathematics Teacher,. V 3, find the volume of the solid that results from revolving The area bounded by y ex, y 1, and x 2 around the x-axis. V _ V _ V. For a solid of revolution generated by revolving a region about the y-axis, the inner and outer radii are functions. .

Re rotating around the jogger xaxis, prior knowledge of basic ideas concerning volumes is useful. Let yi be a value in the ith interval yi1. Find their points of intersection x3 x. Region to Revolve about xaxis, so the volume of a tiny slice would be r2 dx where dx is the thickness. The approximating washers are produced, so the radius is just y in this case. Instructorapos, yi, resulting Solid, the ith washer and its how volume are shown in Figure.

When we developed the disk method for computing volumes we illustrated the generation graph of the disks by revolving a rectangle about an axis 308, finally, v 04 x2 dx, the solid of revolution is generated. The approximation process involves generating a partition and constructing the washers. Developed by Lila Roberts, several physical props are suggested that are useful for helping students understand the geometric concepts involving the washer method.