Bro what's wrong with RU-vid lectures, it is also a type of source isn't it, please don't depreciate it. Furthermore, in this digitalized era, lots of things could be learned more efficiently including using ur calculator. Besides, the purpose of school is to teach you how to learn and digest information yourself instead of spoonfeeding you. You should know that your education system is broken when you expect your teacher to teach you every single thing you need except for the skill to search and digest the information yourself. “Give a man a fish, and he will be hungry again tomorrow; teach him to catch a fish, and he will be richer all his life.”
