The swastika curve is Cundy and Rollett's (1989, p. 71) name for the quartic curve with Cartesian equation
 |
(1)
|
and polar equation
 |
(2)
|
A related family of algebraic curves is
 |
(3)
|
for integers 
. M. Sotelo (pers.
comm., Dec. 28, 2021) suggested the case 
. Each member has rotational
symmetry of order 4 about the origin.
It is unbounded, with oblique asymptotes 
.
