A real function is said to be analytic if it possesses derivatives of all orders and agrees with its Taylor series in a neighborhood of every point.
Real Analytic Function
See also
Analytic Function, Real FunctionExplore with Wolfram|Alpha
Cite this as:
Weisstein, Eric W. "Real Analytic Function." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/RealAnalyticFunction.html