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.
The equations of the circle and the other conic sectionsâellipses, parabolas, and hyperbolasâare quadratic equations in two variables. Given the cosine or sine of an angle, finding the cosine or sine of the angle that is half as large involves solving a quadratic equation.