Is it possible to do well in upper level physics classes with a weak foundation in differential equations? I've never taken a DiffEq class. Some of the extreme basics were covered in Calc 2, and there will be a crash course in DiffEq in my Mathematical Methods in Physics class (using the Boas book.) I plan on taking Mechanics next semester, but a senior student suggested I take an actual DiffEq class first. The problem with that is I'm an older student (27), with a mortgage to pay and a full time job. I can't afford to go to college for an extra year, and putting off mechanics could throw me off my pace to graduate on time. It's only offered during fall semesters. Luckily I have a job that allows me to study and do homework while at work, so I'm able to spend some time on the homework problems without losing any time outside of what I would have spent at work anyway. Should I be able to pick up the DiffEq I need on the fly? Or is it imperitave that I take the time for an actual DiffEq class. On a similar note, are there any good books designed for self-study of DiffEq I could grab for the summer? Thanks.