In calculus we have to get the volume of a sphere forumla by integration (the sheet is here, it's a .doc). Quoting from the page (superscripts of the squared stuff don't show up obviously): ...
IN the second volume of his large treatise on the integral calculus, Mr. Edwards deals with multiple integrals, gamma functions, Dirichlet integrals, definite integrals in general, contour integration ...