Curves69 of 113
Strophoid
Isaac Barrow, 1669; named by Enrico Montucci, 1837
Take a line D, a point O on it and a point F off it. Each line through F meets D at a point P, and the strophoid is made of the two points M on that line with PM = PO. When OF is square to D it is the right strophoid. The name, from the Greek strophos, a twisted cord, is Montucci’s.
y(x² + y²) = b(x² - y²) + 2cxy
On mathcurve.com as Strophoïde