i'm taking a subject heavy in ODE's this semester, and as people have said, know your differentiation/integration rules and techniques, and you'll pick it up easily.
only identities i've had to commit to memory have been the hyperbolic trig function identities. the remainder i've retained from high school maths.
with the exception of polar co-ordinates & applications of polar integration, because i'd never seen them before, and the class had assumed knowledge in them, its been a pretty cruisy run.
from what i hear, i'm glad i'm jumping ship before hitting PDE's.
