David Little  
Mathematics Department Penn State University Eberly College of Science University Park, PA 16802 
Office: 403 McAllister Phone: (814) 8653329 Fax: (814) 8653735 email:dlittle@psu.edu 



Volumes of Solids Generated by Rotation: Washer Method
The following applet approximates the volume of the solid generated by rotating the region of the xyplane bounded by the curves y=f(x) and y=g(x) for a ≤ x ≤ b about the horizontal line y=A. Simply enter the functions f(x) and g(x) and the values a, b, A and 0 ≤ n ≤ 100, the number of subintervals. The values a, b and A can be changed by simply typing a new value, such as "1.2345", "pi/2", "sqrt(5)+cos(3)", etc. You may also change these values by using the up/down arrow keys, dragging the corresponding point left or right, or dragging the corresponding line up or down. To move the center of the graph, simply drag any point to a new location. To label the xaxis in radians (i.e. multiples of pi), click on the graph and press "controlr". To switch back, simply press "controlr" again. You can rotate the object about the center of the screen by dragging the mouse while holding down the SHIFT key. Here is a list of functions that can be used with this applet.
© 2005 David P. Little Download this applet for offline viewing (includes source code). The above applet uses the Java Math Expression Parser (JEP) developed by Singular Systems 