
 Visualizations for Volumes of Solids in Calculus (Site not responding. Last check: 20071105) 
  Rather than introduce volumes of solids of revolution by a purely formuladriven approach, these demos provide the opportunity for visualization of the basic approximating elements that lead to the standard calculus expressions that, when computed, give the desired volumes. 
  We tell students that we can cut the solid into pieces that have a known cross section or, in the case of solids of revolution, we dissect the surface of revolution into "disks", "washers," or "cylindrical shells". 
  Solids of Revolution: The Method of Shells involves revolving a region bounded by a curve y = f(x) and the domain interval [a,b] about the yaxis. 
 mathdemos.gcsu.edu /solids (972 words) 
