Three "Problem Plus" from Stewart Calculus 1. The problem statement, all variables and given/known data Please visit Google Book for online access to the Stewart Calculus 6ed. http://books.google.com/books?id=EBE3vMmGu50C&pg=PP1&dq=stewart+calculus&ei=gYdPSvXyB4_AlQTg9PCACw The problem No. 3,4 and 8 that are located on Page 380 and 381. 2. Relevant equations 3. The attempt at a solution for prob 3: it's hard to work out two points of intersection since the equation is cubic. for prob 4: i don't figure out how to choose the "direction" of cross-sections. for prob 8: we need to calculate the volume of the overlap section. but how? Thanks!!!