One of the schools I'm applying to recommends taking PChem if using AP credit to replace Gen Chem. My research PI thought this was the greatest idea ever. And it just so happens that the course taught by the best professor at our school fits perfectly into my schedule and leaves me the perfect amount of time to volunteer and work. So it made sense to sign up. That said, I haven't taken Calculus since 1999 and my last physics class was in 2000. Diff-Eqs is more recent at a whopping 2001. Since class starts next week, is there anything I should do in the mean time to prepare? I'll be done with most med school applications by Wednesday.