This is sort of a two part question, so bear with me. I just recently graduated with a BS in chemistry, and I applied to a couple PhD programs for next fall (I deliberately waited until after graduating to apply to graduate school for a number of reasons!). I'm working a part time job right now (chemistry related) which I very much enjoy, but I'm not entirely sure how long it will last. Anyways, this spring I was thinking of seeing if I could sit in or audit some kind of upper level math or physics class, just so I could pick up a few things before I start graduate school (assuming I get in somewhere!!!). I was wondering if any of you have suggestions as to what kind of class I should take. I'm probably going to do physical chemistry in graduate school. Also, I graduated with a math minor, so I have 3 semesters of calculus, discrete math, and linear algebra under my belt. I'm thinking of maybe looking into a class where I could learn some things about say, for example, differential equations, or Fourier analysis. Any suggestions?