I am in the 3rd grade of high school and we have a very weird math program.Since the school is specialised for economics we don't study trigonometry in the 3rd grade ,instead we learn about interest rates and how to calculate credits etc... Regardless, we have additional lections (which I am attending) where we learn about induction, limits, more on functions and some differential and integral calculus but only general concepts that don't use trig. The thing is that I want study maths at uni, so I study trig at home at my own, and I am really bad at writing proofs (can't do even the simplest ones).So how should I learn trigonometry, introduction to calculus and go through "How to Prove it" (Daniel J. Velleman) at the same time? I think that if I don't do proofs while studying trigonometry I should never learn it properly. And yeah, the school policy forbids dropping classes once they are signed. Anyways, my question is : what to focus on ?