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).
Example 1. Find the domain and range of the graph of: x 2 + y 2 - 4x - 6y + 13 = 0. Solution. Because A = C 0 and B = 0, the equation represents a circle or one of its degenerate forms. Convert equation from general to standard form, then find the centre and the radius of the circle. The centre is at (2, 3), and the radius is 0. This is an example of a point circle.