Fermat spiral
From HandWiki
A planar transcendental curve the equation of which in polar coordinates has the form
$$\rho=a\sqrt\phi.$$
To each value of $\phi$ correspond two values of $\rho$ — a positive and a negative one. The Fermat spiral is centrally symmetric relative to the pole, which is a point of inflection. It belongs to the class of so-called algebraic spirals.
They were first studied by P. Fermat (1636).
<img style="border:1px solid;" src="https://www.encyclopediaofmath.org/legacyimages/common_img/f038420a.gif" />
Figure: f038420a
References
| [1] | A.A. Savelov, "Planar curves" , Moscow (1960) (In Russian) |
Comments
References
| [a1] | J.D. Lawrence, "A catalog of special plane curves" , Dover, reprint (1972) |
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