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Friday, January 24, 2014

Finding Equation - Circle, 3

Category: Analytic Geometry, Plane Geometry

"Published in Newark, California, USA"

Find the equation of a circle having as diameter the line segment from (-1, 1) to (3, 4).

Solution

To illustrate the problem, it is better to draw the figure as follows

Photo by Math Principles in Everyday Life

The first thing that we need to do is to get the center of a circle by using the midpoint formula of the two points as follows









Hence, the center of a circle is C (1, 5/2).

Next, get the radius of a circle by using the distance formula of two points as follows 









Therefore, the equation of a circle is