$\"\"$

The center of the sphere is $\"\"$ .

Consider a point on the sphere $\"\"$ .

Distance between the vertices $\"\"$ and $\"\"$ is $\"\"$ .

Distance between $\"\"$ and $\"\"$ is $\"\"$ :

$\"\"$

Distance between $\"\"$ is the radius of the sphere.

Substitute $\"\"$ in the above equation.

$\"\"$

Squaring on both sides.

$\"\"$

Thus, the equation of the sphere is $\"\"$ .

$\"\"$

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