The February 16, 2006 PoW

Let <x> = d(x,Z), i.e., the distance x is to the nearest integer. It is well known that S0 <10nx>/10n represents a continuous, nowhere differentiable function which has a period of 1. Find the area under the curve on the interval [0,1]. And find the maximum of the curve, and all x-values where the maximum occurs on [0,1].

area figure 1 + area figure 2 + area figure 3 ...+ ...