Spijker's lemma

From Wikipedia, the free encyclopedia

In mathematics, Spijker's lemma is a result in the theory of rational mappings of the Riemann sphere. It states that the image of a circle under a complex rational map with numerator and denominator having degree at most n has length at most 2nπ.

[edit] See also

• Buffon's needle

[edit] External links

• Eric W. Weisstein, Spijker's Lemma at MathWorld.

[edit] References

• Wegert, Elias; Trefethen, Lloyd N. (Feb 1994). "From the Buffon Needle Problem to the Kreiss Matrix Theorem". The American Mathematical Monthly 101 (2): 132-139.