Teurema un quaart da Koebe

From Wikipedia

Si  f:\mathbb D \rightarrow \mathbb C  a l'è una aplicazziun cunfurma, alura


\frac{1}{4}
\left(1-\vert z     \vert^2    \right)
\vert f^{\prime}(z)     \vert
\leq dist\left(f(z),\partial f(\mathbb D )    \right)
\leq
\left(1-\vert z     \vert^2    \right)
\vert f^{\prime}(z)     \vert
par cada  z\in\mathbb D .

[redatá] Refereenz

Ch.Pommerenke, 'Boundary behaviour of conformal maps', Springer Verlag, 1992