View source for Cochleoid

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<span id="Fig1">
[[File:Cochleoid-1.png| right| frame| Figure 1. The cochleoid ([[Media:Cochleoid-1.pdf|pdf]]) ]]
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A plane transcendental curve whose equation in polar coordinates is
\begin{equation}
\rho = a\frac{\sin\varphi}{\varphi}.
\end{equation}

The cochleoid has infinitely many spirals, passing through its pole and touching the polar axis (see Fig.). The pole is a singular point of infinite multiplicity. Any straight line through the pole $O$ intersects the cochleoid; the tangents to the cochleoid at these intersection points pass through the same point.

The [[Inversion|inverse]] of the cochleoid with respect to the origin is the [[quadratrix of Hippias]].

====References====
<table>
<TR><TD valign="top">[1]</TD> <TD valign="top">  A.A. Savelov,   "Planar curves" , Moscow  (1960)  (In Russian)</TD></TR>
<TR><TD valign="top">[a1]</TD> <TD valign="top">  J.D. Lawrence,   "A catalog of special plane curves" , Dover  (1972) ISBN 0-486-60288-5  {{ZBL|0257.50002}}</TD></TR>
</table>