MATH HISTOTY: A very difficult question aboutthe history of mathematics

[Lance_Turbo]

This post from your previous thread on this exact topic contains links to multiple examples of what you’re looking for.

@Wendell_Wagner

Here’s a couple of webpages with examples of what you’re looking for:

ho.history overview - Widely accepted mathematical results that were later shown to be wrong? - MathOverflow

fake proofs - In the history of mathematics, has there ever been a mistake? - Mathematics Stack Exchange

Here is one of several…

A convergent infinite series of continuous functions is continuous. Cauchy gave a proof of this (1821). See Theorem 1 in Cours D’Analyse Chap. VI Section 1. Five years later Abel pointed out that certain Fourier series are counterexamples.