Consider a sphere with center and radius .
What is its equation? (Place the radius portion on the right hand side and the rest of the equation on the left.)
Answer: =
What point on the sphere is directly above the sphere’s center (in the positive direction)?
Answer: (,,)
What two points on the sphere are directly above the point ? (As before, “above” means in the positive direction.)
Lower point: (,,)
Upper point: (,,)

You can earn partial credit on this problem.