Escitalopram is an oral drug that is used for treating depression and generalized anxiety disorder. Chemically, escitalopram is similar to citalopram . Both are in a class of drugs called selective serotonin reuptake inhibitors (SSRIs), a class that also includes fluoxetine , paroxetine and sertraline .
1 A circle is all of the points that are a fixed distance, known as the radius, from a given point, known as the center of the circle. 2  Explore the standard equation of a circle using the applet below (Go here for a larger version).
Definition of Circle. Definition: A circle is the set of all points that are the same distance, r, from a fixed point. General Formula: X 2 + Y 2 =r 2 where r is the radius. 1  Unlike parabolas, circles ALWAYS have X 2 and Y 2 terms. 2  X2 + Y2=4 is a circle with a radius of 2 (since 4 =22). 3  Remember that a circle is a locus of points.