\begin{definition}[Definition:Quadratrix of Hippias/Definition 1]
The '''quadratrix of Hippias''' is the plane curve defined in Cartesian coordinates as:
:$y = x \cot \left({\dfrac {\pi x }{2 a} }\right)$
for some real constant $a \in \R$.
:600px
The above diagram illustrates the '''quadratrix of Hippias'''.
\end{definition}