Polar equation:
r = a/θ
Click below to see one of the Associated curves.
The roulette of the pole of a hyperbolic spiral rolling on a straight line is a tractrix.
Pierre Varignon (1654-1722) was professor of mathematics at Collège Mazarin and later at Collège Royal. Led into mathematics by reading Euclid he also read Descartes' Géométrie and thereafter devoted himself to the mathematical sciences. He was one of the first French scholars to recognise the value of the calculus. His chief contributions were to mechanics.
Taking the pole as the centre of inversion, the hyperbolic spiral r = a/θ inverts to the spiral of Archimedes r = aθ.
The URL of this page is:
http://www-history.mcs.st-andrews.ac.uk/Curves/Hyperbolic.html