Difference between revisions of "Van der Waerden function"

From specialfunctionswiki
Jump to: navigation, search
Line 11: Line 11:
 
</div>
 
</div>
 
=Properties=
 
=Properties=
<div class="toccolours mw-collapsible mw-collapsed">
+
[[van der Waerden function is continuous]] <br />
<strong>Theorem:</strong> The van der Waerden function is [[continuous]].
+
[[van der Waerden function is nowhere differentiable]]<br />
<div class="mw-collapsible-content">
 
<strong>Proof:</strong>
 
</div>
 
</div>
 
 
 
<div class="toccolours mw-collapsible mw-collapsed">
 
<strong>Theorem:</strong> The van der Waerden function is [[nowhere differentiable]] on $\mathbb{R}$.
 
<div class="mw-collapsible-content">
 
<strong>Proof:</strong> █
 
</div>
 
</div>
 
  
 
=See Also=
 
=See Also=

Revision as of 03:16, 6 July 2016

Define $s(x)=\inf_{n \in \mathbb{Z}} |x-n|$ (i.e. the distance from $x$ to the set of integers $\mathbb{Z}$). The van der Waerden function is defined by the formula $$V(x)=\displaystyle\sum_{k=0}^{\infty} \dfrac{s \left(10^k x \right)}{10^k}.$$ Note: to calculate $s(x)$ you may use $s(x)=\min \left(2^n x - \lfloor 2^n x \rfloor, \lceil 2^n x \rceil - x \right)$, where $\lfloor \cdot \rfloor$ denotes the floor function and $\lceil \cdot \rceil$ denotes the ceiling function.


Properties

van der Waerden function is continuous
van der Waerden function is nowhere differentiable

See Also

Takagi function

References

[1]