A reproduction of a proof by Leonard Euler, which I dug out of the back of a calculus textbook with the help of Brian Burrell. This was in MATH 233 at the University of Massachusetts, Amherst, Fall 2015.
A simple homework format.
Has: header on every page, page numbers, enumerated list to do problems in, some explanatory comments in code about what does what.
Tip: use inline formulas to shorten output.