My math skills were always bad. I mean, even though I had one of the best scores in school, I could never explain why it works, e.g. why 9^1/2 is the same as sq

My math skills were always bad. I mean, even though I had one of the best scores in school, I could never explain why it works, e.g. why 9^1/2 is the same as sqr(9). Since I want to self-study the Quant Finance, I decided to refresh and develop my math skills up to the Calculus. This website is amazing! Not only it's a good refresher, it's the best source of knowledge created by one man.