The Brocard Angle and a Geometrical Gem from Dmitriev and Dynkin
Ádám Besenyei · American Mathematical Monthly · 2015
In a celebrated paper on the eigenvalues of special matrices, N. Dmitriev and E. Dynkin formulated and proved a nice geometrical lemma. This lesser-known gem provides a simple proof of the maximal value of the Brocard angle and yields also the solution to some challenging problems from the past few decades.