Definition:Fermat's Spiral

Definition
Fermat's spiral is the locus of the equation expressed in Polar coordinates as:
 * $r^2 = \dfrac a \theta$


 * FermatSpiral-positive.png

For negative $r$, the figure appears as:


 * FermatSpiral-negative.png

and when plotted both together:


 * FermatSpiral.png

Also known as
Some sources refer to this as a parabolic spiral.