Melo, Helena SousaCabral, João2014-01-032014-01-032010-11Melo, Helena S., Cabral, João (2010). "Numerical range, numerical radii and the dynamics of a rational function". In Elaydi, Saber N. et al. (Eds.), «Discrete Dynamics and Difference Equations» (World Scientific), pp 336-344. http://dx.doi.org/10.1142/9789814287654_0027.978-981-4287-64-7978-981-4466-65-3 (ebook)http://hdl.handle.net/10400.3/2519Texto publicado no seguimento da comunicação apresentada na "Twelfth International Conference on Difference Equations and Application", no Instituto Superior Técnico em Lisboa, 23-27 Julho 2007.Sometimes we obtain attractive results when associating facts to simple elements. The goal of this work is to introduce a possible alternative in the study of the dynamics of rational maps. In this study we use the family of maps f(x) = (x^2-a)/(x^2-b), making some associations with the matrix A of its coefficients. Calculating the numerical range W(A), the numerical radii r(A) and br(A), the boundary of the numerical range @W(A), powers and iterations, we found relations very interesting, especially with the entropy of this maps.engNumerical RangeRational Functionbook part