"If your teacher isn't able or willing to help, how can you get your questions answered?"

Are you willing to bring your homework home?
Do you want a tutor?
Do you want help finding lectures?
Do you think anyone at the university could explain this better?

My son is a top-down learner. Middle school level texts make no sense to him. However, if I give him a college level textbook or lecture FIRST, then he sees how the incomplete/simplified information fits into the complete picture. When my son doesn't understand, what he means is that he wants the big, complicated, college-level picture. When your son's teachers say "just do it", they might be saying that he knows enough to answer the questions and maybe that they aren't able to explain at the depth your son really NEEDS in order to comprehend it fully.

Just a guess??