How many of us have had bad teachers, professors, TAs, and/or instructors? To answer myself, all of us have! Authority figures who are horrible at their job or abuse their power have been a thorn in my side since junior high. It has taken me a dozen years to learn how to process such frustration.
As always, parents will tell you that teachers are just doing their best, and to some extent, they are right. The majority of teachers are doing what they think will help you the most, and that is respectable. Their efforts sometimes get misguided, though. It can spin in many directions. I've had teachers that don't understand the difference between homework that helps and homework that doesn't. These teachers tend to assign lots of busy work that doesn't actually benefit you after the first 15 problems. I've had teachers that are too boring or too energetic. One teacher has such a monotone voice that half the class falls asleep, while the other one is bouncing off the walls and telling us about the chicken they fed their cat this morning. Especially as a band student, there are teachers and conductors who try using the 'put you down, to build you up' philosophy. They are snappy, call people out for one-time mistakes, and criticize students beyond their abilities necessary to that class. Most of these teachers in one way or another believe they are doing something to help you, but only end up hurting your capability to learn.
On the other end of things, there are the instructors who truly don't care. It could be the teacher that is begging for the oh-so-soon retirement, the coach being forced to teach, or the grumpy professor that lets their home life affect their instructing. These select few are the most vexing because it's hard to even make an effort when your teacher isn't trying either.
To tackle these situations you'll need a toolbox of knowledge: 1. Remember that no matter who is teaching you, the education you're attempting to receive is for your benefit. Don't waste a potentially important class on a bad teacher. 2. Report cards don't care about how good or bad a teacher is. When applying to colleges, there's no comment section to let them know the 'D' in Algebra 'wasn't your fault'. Your GPA won't forget you failed Biology 101 because Professor No-Good didn't prepare you for the exams. 3. Getting frustrated or lashing out at a teacher will hurt your grade more than it will help it. Back talking or angering someone with authority over you is always going to be negative rather than a positive. 4. You are not there for the teacher! You are there because something about that class is going to help you in your future or get needed credit hours. Ignore bad teaching and get to learning.
It took me a while to figure out how to deal with a bad teacher, and it took even longer to actually deal with them. I can't stress enough how important this is to your present schooling and your future career. It carries over to handling terrible bosses and managers. Keep your a cool head and study hard.