Bifolium
Encyclopedia
- For the brachiopodBrachiopodBrachiopods are a phylum of marine animals that have hard "valves" on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection...
phylumPhylumIn biology, a phylum The term was coined by Georges Cuvier from Greek φῦλον phylon, "race, stock," related to φυλή phyle, "tribe, clan." is a taxonomic rank below kingdom and above class. "Phylum" is equivalent to the botanical term division....
, see Bifolium (brachiopod).
The bifolium is a quartic plane curve
Quartic plane curve
A quartic plane curve is a plane curve of the fourth degree. It can be defined by a quartic equation:Ax^4+By^4+Cx^3y+Dx^2y^2+Exy^3+Fx^3+Gy^3+Hx^2y+Ixy^2+Jx^2+Ky^2+Lxy+Mx+Ny+P=0....
of the equation:
In polar coordinates, its equation is
External links
- http://www.geom.uiuc.edu/~fjw/pisces/docs/models/Bifolium.html
- Bifolium at MathWorld