See [accumulatedCrossSections/exercises/crossSections2Ways.tex](https://github.com/mooculus/calculus/blob/master/accumulatedCrossSections/exercises/crossSections2Ways.tex) Towards the end of this problem they ask:  and they haven't learned integration by parts yet so can't do the first one of these integrals after expanding.
See accumulatedCrossSections/exercises/crossSections2Ways.tex
Towards the end of this problem they ask:

and they haven't learned integration by parts yet so can't do the first one of these integrals after expanding.