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).
Using this definition of a circle (the set of points all at the same distance from a given point called the center) we can graph a circle on a coordinate system. The equation of this circle, with its center at the origin, and its radius equal to 3 (the square root of 9) is: