I am currently a first year undergraduate but I still feel as if I cannot read many undergraduate level books. At the moment I am interested in reading some classics. I have already read Euler's Elements of Algebra which I thoroughly enjoyed and thought was much clearer than any algebra book I have read up to now. This surprised me, because I thought books by Euler would be difficult and contain convoluted proofs. In short, I am looking for books by Euler that are accessible to strong high school students. My thoughts are:
-Mechanica (I found an online english translation of this which I am liking so far, but I can't tell if I will need previous knowledge of mechanics/advanced calculus to fully understand the book, e.g. calculus of variations?)
-Analysis of the infinite 1 and 2
-His Differential calculus
-His integral calculus
Thanks