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).
Thus, using the theorem ofPythagoras,x 2 +y 2 = r ,and this is the equation of a circle of radius r whose centre is the origin O(0,0). Key Point The equation of a circle of radius r and centre the origin isx 2 +y = r .www.mathcentre.ac.uk 3 c mathcentre 2009. 3.ind the equation of the circle with given centre and radius:(a) centre (3,5), radius 3; (b) centre (â2,3), radius 1; (c) centre (â1,â3), radius 2;(d) centre (2,â2), radius 5; (e) centre (0,5) radius 4.2.