tangency
101Touch (disambiguation) — For the sense of touch, see:* Somatosensory system, for the neurophysiological basis of touch * Haptic perception, for the ability to recognize objects through touch * Haptic communication, for the study of human touching behaviour * Haptic… …
102Hairy ball theorem — The hairy ball theorem of algebraic topology states that there is no nonvanishing continuous tangent vector field on the sphere. If f is a continuous function that assigns a vector in R3 to every point p on a sphere such that f ( p ) is always… …
103Descartes' theorem — For other uses, see Descartes theorem (disambiguation). In geometry, Descartes theorem, named after René Descartes, establishes a relationship between four kissing, or mutually tangent, circles. The theorem can be used to construct a fourth… …
104Dupin cyclide — A Dupin cyclide In mathematics, a Dupin cyclide or cyclide of Dupin is any geometric inversion of any standard torus. In particular, the standard (or circular) tori are themselves examples of Dupin cyclides. They were discovered by (and named… …
105History of calculus — History of science …
106Deltoid curve — The red curve is a deltoid. In geometry, a deltoid, also known as a tricuspoid or Steiner curve, is a hypocycloid of three cusps. In other words, it is the roulette created by a point on the circumference of a circle as it rolls without slipping… …
107Tractrix — (from the Latin verb trahere pull, drag ), or tractrice, is the curve along which a small object moves, under the influence of friction, when pulled on a horizontal plane by a piece of thread and a puller that moves at a right angle to the… …
108Semiperimeter — In geometry, the semiperimeter of a polygon is half its perimeter. Although it has such a simple derivation from the perimeter, the semiperimeter appears frequently enough in formulas for triangles and other figures that it is given a separate… …
109Jet bundle — In differential geometry, the jet bundle is a certain construction which makes a new smooth fiber bundle out of a given smooth fiber bundle. It makes it possible to write differential equations on sections of a fiber bundle in an invariant… …
110Linear system of divisors — A linear system of divisors algebraicizes the classic geometric notion of a family of curves, as in the Apollonian circles. In algebraic geometry, a linear system of divisors is an algebraic generalization of the geometric notion of a family of… …
