A shortcut for finding the eigenvectors of a $2\times 2$ matrix.

The tribonacci constant conjugate makes an appearance at the intersection of $y=\frac{x-1}{x}$ and the unit circle. Also a geometric construction by Xerardo Neira.

The golden mean is found in the pentagon. Silver mean in the octagon. But what about the other metallic means?

by Vera W. de Spinadel

Redesign + new math + secret project