Ack, I'm sorry, I made you go and look up which section I'm in. Thank you for that effort, and for your helpful reply. I will be continuing to attend the night section, since I need to be up at 6PM for two other classes anyway.
I take it the material about reducing the order of second-order ODEs is in the textbook somewhere (e.g. 3.4?) If not I'll try and poke some of the other students after this week's lecture.