Differential equations is very different from normal calc. It requires a lot of memorization of different methods of solving equations. Luckily, in online school we are allowed access to our notes. But also because of the rampant cheating on the midterm, the final was impossibly hard. The best students and even cheaters couldn't score above 80% and most people failed. It's a hard course all around but if you practice a lot then you'll do fine.