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).
The equation of a circle comes in two forms: 1) The standard form: (x-h)2 + (y-k)2 = r2. 2) The general form: x2 + y2 + Dx + Ey + F = 0, where D, E, F are constants. If the equation of a circle is in the standard form, we can easily identify the center of the circle, (h, k), and the radius, r. Note: The radius, r, is always positive. Example 1: (x-2)2 + (y-3)2 = 4. (a) Find the center and radius of the circle. (b) Graph the circle. Note: A common mistake is to take h= -2 and K= -3.