Fabius function: Difference between revisions

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Add two graphs of the Fabius function, and mention a few more properties
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[[Image:Graph of the Fabius function between 0 and 1.png|thumb|Graph of the Fabius function on the interval <nowiki>[0,1]</nowiki>.]]
[[Image:Graph of the Fabius function.png|thumb|Extension of the function on the nonnegative real axis.]]
 
In mathematics, the '''Fabius function''' is an example of an infinitely differentiable function that is nowhere [[analytic function|analytic]], found by {{harvtxt|Fabius|1966}}.
 
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where the ''&xi;''<sub>''n''</sub> are [[independence (probability)|independent]] [[uniform distribution (continuous)|uniformly distributed]] [[random variable]]s on the [[unit interval]].
 
This function satisfies the functional equation ''f''&prime;(''x'')=2''f''(2''x'') (where ''f''&prime; denotes the derivative of ''f'') for 0≤''x''≤1. There is a unique extension of ''f'' to the nonnegative real numbers which satisfies the same equation: it can be defined by ''f''(''x''+1) = 1−''f''(''x'') for 0≤''x''≤1 and ''f''(''x''+2<sup>''r''</sup>) = −''f''(''x'') for 0≤''x''≤2<sup>''r''</sup> with ''r''≥1 integer; it is strongly related to the [[Thue–Morse sequence]].
 
==References==