You shouldn't use an LLM to do your homework but you can certainly use it to learn and clarify things you don't understand. I teach math and physics and tested local LLMs for learning and I can say they really help, at least in these subjects. The best option is to learn from books and making your homework, but when you're stuck with something that you don't understand, ask a good LLM to clarify things, give examples and context. I tested myself while learning about differential geometry and relativity, it really speeds up the learning process and understanding. But don't use them as a primary source, nothing beats a good book and practice on that. I wish there was something like that when I was in college, I wouldn't have carried some misunderstandings so many years. Being just a tool it's up to you if you use it responsibly or not, as any other tool.