That's no reason to bite them, Harry, my dear. Or to strongly react in any way. You may look down on them, especially if they are a math teacher, but then again, if they aren't supposed to teach logarythms at the level they work in, that is entirely forgivable. A much more legitimate reason for hatred would be deliberate abusive behavior. If they are abusive AND incompetent... then, at that point, desprate times require desperate measures. It seldom happens: incompetent teachers are usually the most lenient, and they deliberately are as lenient and low-profile as possible.