**Minkowski's Question Mark Function**

In mathematics, the **Minkowski question mark function** (or the **slippery devil's staircase**), denoted by ?(*x*), is a function possessing various unusual fractal properties, defined by Hermann Minkowski in 1904. It maps quadratic irrationals to rational numbers on the unit interval, via an expression relating the continued fraction expansions of the quadratics to the binary expansions of the rationals, given by Arnaud Denjoy in 1938. In addition, it maps rational numbers to dyadic rationals, as can be seen by a recursive definition closely related to the Sternâ€“Brocot tree.

Read more about Minkowski's Question Mark Function: Definition, Intuitive Explanation, Recursive Definition For Rational Arguments, Self-symmetry, Properties of ?(*x*), Conway Box Function, Historical References

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