극곡선의 접선은 접선,tangent_line으로
극(pole) ⇔
tmp Bmks en
Families of Polar Curves
http://mathonline.wikidot.com/families-of-polar-curves-r-sin-bth-and-r-cos-bth
Families of Polar Curves
http://mathonline.wikidot.com/families-of-polar-curves-r-sin-bth-and-r-cos-bth