Fermat's Spiral and the Line Between Yin and Yang.

The article focuses on the Fermat's spiral, the distinctive yin-yang line in the class of curves algebraic in polar coordinates. It says that yin-yang is a concept that came from ancient Chinese philosophy. Hence, to prove Fermat's spiral, D denote a disk of unit area wherein set A ⊂ D if it measures ½ and the maximum symmetric subset of A measure ¼. It adds that β divides into two congruent set, it intersects each concentric of D twice and in each radius of D once.