Most of your encounters with these integrals will not require you to evaluate them. However it is a good idea to develop some experience in doing so, to build your confidence in them. One of these is generally done by your performing a multiple integration, which means a sequence of ordinary integrations. To do so you must do three things: determine the integrand as a function of your variables of integration; determine the area or volume element of the integral in terms of same; and find appropriate limits of integration on the ordinary integrals obtained. Once this is done you then perform ordinary integrations. We discuss these steps here.
31.2 Expressing Surfaces Parametrically or in Appropriate Form for Integrations
31.3 Determining the Integrand
31.4 Determining the Area or Volume Element
31.5 Setting up Correct Limits of Integration
31.6 Doing the Integrals