The Dottie Number

232 · Lawrencecpaulson · June 26, 2026, 3:10 p.m.
Summary
This blog post delves into the mathematical properties of the Dottie number, a fixed point of the cosine function, and presents formal proofs using Isabelle for its existence, uniqueness, and transcendental nature. The author explores convergence through iteration of the cosine function, showcasing various computer algebra techniques to validate the findings.