This is a more general
specimen of the right strophoid.
Now the line OO' through pole O and fixed point O' is no longer perpendicular to the
construction line l.
The parameter a = π/2 for the right strophoid can now also have other values,
in Cartesian coordinates: x^{3} + x y^{2}  x^{2} + y^{2} =
y (x^{2} + y^{2}  2x) cotan a
The curve is a pedal of the parabola, and a special
case of the general strophoid. Sometimes the
oblique strophoid itself is called the 'general strophoid'.
