A First Course in Complex Analysis · Problem 8.4.6
Taylor and Laurent Series — Beck, Marchesi, Pixton & Sabalka
Mathematics — Complex Analysis
Problem
Show that Corollary 8.1.10 is false when translated to R. That is, find a real analytic function f:R→R and a point x0∈R such that the radius of convergence of the power series expansion of f at x0 is strictly less than the distance from x0 to the boundary of the domain of f.