IMC 2003 · Problem 5

Day 120 points10th IMC · Cluj-Napoca, Romania

Statement

Let g:[0,1]Rg : [0,1] \to \mathbb{R} be a continuous function and let fn:[0,1]Rf_n : [0,1] \to \mathbb{R} be a sequence of functions defined by f0(x)=g(x)f_0(x) = g(x) and

fn+1(x)=1x0xfn(t)dt(x(0,1],  n=0,1,2,).f_{n+1}(x) = \frac{1}{x} \int_0^x f_n(t)\,dt \quad (x \in (0,1], \; n = 0, 1, 2, \dots).

Determine limnfn(x)\lim\limits_{n \to \infty} f_n(x) for every x(0,1]x \in (0,1].

Official solution

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