$\"\"$

Center $\"\"$ and passes through the origin $\"\"$ .

Find the radius, and apply distance formula.

$\"\"$

Substitute $\"\"$ .

$\"\"$

$\"\"$ $\"\"$

$\"\"$

The radius of the circle is $\"\"$ , So $\"\"$ . $\"\"$

The equation of a circle with center $\"\"$ and radius r units is $\"\"$ .

Substitute $\"\"$ .

$\"\"$ $\"\"$

The equation of the circle is $\"\"$ .