Si|z|=R entonces|N−1∑k=0akzk|≤N−1∑k=0|ak|Rk. EligeL0 para que siR≥L0,\[\sum_{k=0}^{N-1}\left|a_{k}\right| R^{k} ...Si|z|=R entonces|N−1∑k=0akzk|≤N−1∑k=0|ak|Rk. EligeL0 para que siR≥L0,N−1∑k=0|ak|Rk≤12|aN|RN. entonces Entonces siL≥L0 yz está afueraS, tenemos\[\begin{aligned} \left|a_{N} z^{N}\right| &=\left|p(z)-\sum_{k=0}^{N-1} a_{k} z^{k}\right| \\ & \leq|p(z)|+\left|\sum_{k=0}^{N-1} a_{k} z^{k}\right| \\ & \leq|p(z)|+\frac{1}{2}\left|a_…
