Calculus Made Easy

TL;DR — Thompson’s famous calculus primer (2nd edition, 1914): “What one fool can do, another can.”

How much weight it carries: A classic textbook, public domain via Project Gutenberg.

Where this came from

• Will Manidis’s “most underrated PDF” thread, July 2023 — routing record: The Most Underrated PDF on the Internet (July 2023)

292 pages. A copy is archived locally against link rot; the header links the original source.