蜗牛线

蜗牛线（）是一種蜗牛形的曲線，類似環索線，其极坐标系方程如下：
:r=\frac{a \sin \theta}{\theta}

其笛卡儿坐标系方程如下
:(x^2+y^2)\arctan\frac{y}{x}=ay

其參數方程如下
:x=\frac{a\sin t\cos t}{t}
:y=\frac{a\sin^2 t}{t}

蜗牛线是的。
腳註
參考資料
*
[https://www.encyclopediaofmath.org/index.php/Cochleoid Cochleoid*] in the Encyclopedia of Mathematics
Liliana Luca, Iulian Popescu: [http://www.utgjiu.ro/rev_mec/mecanica/pdf/2011-01/3_luca.pdf A Special Spiral: The Cochleoid*] . Fiabilitate si Durabilitate - Fiability & Durability no 1(7)/ 2011, Editura "Academica Brâncuşi", Târgu Jiu,
Roscoe Woods: The Cochlioid*. The American Mathematical Monthly, Vol. 31, No. 5 (May, 1924), pp. 222–227 ([https://www.jstor.org/stable/2299243 JSTOR] )

• Howard Eves: A Graphometer. The Mathematics Teacher, Vol. 41, No. 7 (November 1948), pp. 311–313 ([https://www.jstor.org/stable/27953353 JSTOR] )

外部連結
*[http://www.2dcurves.com/spiral/spiralc.html cochleoid] at 2dcurves.com
*