Cartesian equation:
y4 - x4 + a y2 + b x2 = 0
Polar equation (Special case):
r = √[(25 - 24tan2(θ))/(1 - tan2(θ))]
Click below to see one of the Associated curves.
Cramer (1704-1752) was a Swiss mathematician. He became professor of mathematics at Geneva and wrote on work related to physics; also on geometry and the history of mathematics. He is best known for his work on determinants (1750) but also made contributions to the study of algebraic curves (1750).
The URL of this page is:
http://www-history.mcs.st-andrews.ac.uk/Curves/Devils.html