lemniscate of Bernoulli

English

The lemniscate of Bernoulli with $a=1$

Etymology

From the name of Swiss mathematician Jakob Bernoulli.

Noun

lemniscate of Bernoulli (plural lemniscates of Bernoulli)

1. (mathematics) Any closed curve described by a Cartesian equation of the form $(x^{2}+y^{2})^{2}=2a^{2}(x^{2}-y^{2})$.