The center of the circle is
.
The end points if the diameter are
and
.
The distance between center and one end point is the radius of the circle.
\Distance between two points is
.
Substitute
and
.
The diameter 

.
Radius of the circle is
.
.
The standard form of circle is
.
Substitute
and
in
.

.
The equation of circle is
.
Graph:
\Graph the equation of circle is
.
The equation of circle is
.
Graph:
\Graph the equation of circle is
.
.