Hello! So I'm someone who's been trying to self-learn math, and it's going pretty well, but there's a couple things that still remain difficult to me.
Currently I'm trying to do some basic first and second year undergraduate mathematics (general, so like calculus, linear algebra, etc.) are there any strategies to how to think when solving very complex problems and/or theorems that save the day? I've added a couple images to show the level of problems that I mean, it's probably not very high level but I'm not fully used to using all these new formulas, and I seem to still have some gaps, so if someone could tell me some theorems and formulas (don't worry about the proofs, i can learn them online) that might not be as well-known/covered, but help with the majority of these kinds of problems?
Mainly linear algebra and calculus, but any field of math is fine in general.
And sorry if this should've gone in help-university, it felt sort of inbetween since it wasn't that I needed help on a specific problem, but just general tips.