Washer method, disc method, etc. In what areas or fields would someone make these calculations?
For example, I think 3D printers do some sort of "slicing" algorithm in their CPU in order to print the layers. But, this is a very literal translation of volumes and slices.
Have you encountered anything else? Something where you'd want the 3D volume of some functions to determine some sort of density or total? (Sort of like area under the curve can be used for cumulative density functions in Stats)