Lituus (mathematics)
In mathematics, a lituus is a spiral in which the angle is inversely proportional to the square of the radius (as expressed in polar coordinates).
This spiral, which has two branches depending on the sign of 
, is asymptotic to the 
axis. Its points of inflexion are at 
and 
.
The curve was named by Roger Cotes in a collection of papers entitled Harmonia Mensurarum (1722), which was published six years after his death.