After I graduated university in an unrelated field, I decided I want to learn a couple of math subjects. So I've gathered the interned resources I could find and I studied them on my own. I've been doing this in order to increase my chances of being accepted to a masters program that would require these as prerequisites.
But how am I to prove in my application that I've been learning these subjects through self study? If it were coding, I could have provided some github projects, but regarding mathematics I find it hard to find some meaningful way to attest that you've covered some area unless you've taken a university degree in that field.
