Here are my notes on the time I attended a lecture by Leonhard Euler on Euler Calculus.
1) The Fundamental Theorem of Calculus: ∫f(x)dx = F(b) - F(a)
2) The Sum of Powers Formula: ∑k=0 to ∞ (1 + x^k)
3) Euler's Formula for the Number of Sides on a Circle: (2 + 4π)
These notes are Euler Calculus for beginners. Don't worry if you didn't understand them, I still don't.
Next up: Fermat's Theorem!