Clinician definition, a physician or other qualified person who is involved in the treatment and observation of living patients, as distinguished from one engaged in research. See more. Dictionary.com
In geometry, the foci (/ËfoÊsaÉª/ ; singular focus) are a pair of special points with reference to which any of a variety of curves is constructed. For example, foci can be used in defining conic sections, the four types of which are the circle, ellipse, parabola, and hyperbola. In addition, foci are used to define the Cassini oval and the Cartesian oval.
Table of conics, Cyclopaedia, 1728. In mathematics, a conic section (or simply conic) is a curve obtained as the intersection of the surface of a cone with a plane. The three types of conic section are the hyperbola, the parabola, and the ellipse. The circle is a special case of the ellipse, and is of sufficient interest in its own right that it was sometimes called a fourth type of conic section.