I tried to use LaTeX to take notes in Middle School once, no joke, and I found it quite difficult. LaTeX is meant for explicit typesetting and having fine-grain

I tried to use LaTeX to take notes in Middle School once, no joke, and I found it quite difficult. LaTeX is meant for explicit typesetting and having fine-grained control over your documents. If you want to write an English or Math paper in it, then it's perfect, but I think it's overkill for notes. I now use reStructuredText to write my notes and rst2pdf when I have to print them out to study. It's very simple and I don't have to worry about typesetting. For math...pen and paper. Your math example was well typeset but I doubt you'd have time to do all that in class short of asking the teacher to stop for 15 minutes.