What does the following operation achieve with f; being the values of a function f sampled at equidistant points of a grid? \frac{h}{3}\left(f_{1}+4 f_{2}+f_{3}\right) O An estimation of the derivative at the central point O An estimation of the 2nd-order derivative at the central point An estimation of the integral at the central point An estimation of the Laplacian at the central point

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