Conchoid
From Encyclopedia of Mathematics - Reading time: 1 min
2020 Mathematics Subject Classification: Primary: 53A04 [MSN][ZBL]
of a curve
The planar curve obtained by increasing or decreasing the position vector of each point of a given planar curve by a segment of constant length $l$. If the equation of the given curve is $\rho=f(\phi)$ in polar coordinates, then the equation of its conchoid has the form: $\rho=f(\phi)\pm l$.
Examples: the conchoid of a straight line is called the Nicomedes conchoid; the conchoid of a circle is called the Pascal limaçon.
References[edit]
| [a1] | J.D. Lawrence, "A catalog of special plane curves" , Dover, reprint (1972) Zbl 0257.50002 |
How to Cite This Entry: Conchoid (Encyclopedia of Mathematics) | Licensed under CC BY-SA 3.0. Source: https://encyclopediaofmath.org/wiki/Conchoid5 views | ↧ Download this article as ZWI file
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