
Rigorous proof (O-level Math but Modern Math technique) by reductio ad absurdum (反证法).
【一道题检验你是否具有数学思维(视频版) – 今日头条】

Rigorous proof (O-level Math but Modern Math technique) by reductio ad absurdum (反证法).
【一道题检验你是否具有数学思维(视频版) – 今日头条】
He applied Physics (flux ) Gauss Divergence Theorem ‘DIV’ operator to get the derivative of Volume = Surface Area “
👍 That’s beautifully an example of using Physics to prove Math.