A quartic curve with implicit equation
 |
(1)
|
or
 |
(2)
|
and 
. In parametric form,
 |
 |
 |
(3)
|
 |
 |
 |
(4)
|
The curvature is
 |
(5)
|
REFERENCES:
Lawrence, J. D. A Catalog of Special Plane Curves. New York: Dover, pp. 127-129, 1972.
Shikin, E. V. Handbook and Atlas of Curves. Boca Raton, FL: CRC Press, p. 96, 1995.
