Tangent of Folium of Descartes


Construction according to 1/r = cot t cos t + sin t tan t

References:
R.C. Yates, Curves and Their Properties, pp. 98-99.
蔣聲, 形形色色的曲線, pp. 113-114.
J. Dennis Lawrence, A Catalog of Special Plane Curves, pp. 106-108.