Curves94 of 113
Rose
Guido Grandi, 1723
A sine wave plotted in polar coordinates: the distance from the centre rises and falls as the angle turns. When k is a whole number the rose has k petals if k is odd and 2k if it is even; for any other k the petals cross. It is also the path of a point sliding to and fro along a rod while the rod turns evenly about its middle.
r = a cos(kθ)
On mathcurve.com as Rosace