Question

Find the points on the sphere x2 + y2 + z2 = 4 that are closest to and
farthest from the point (3,1,-1) .

Answer 1

Sphere has radius = 2 and is centered at (0, 0, 0)

Draw diameter line that extends to (3,1, -1). Intersections
with sphere will be closest and farthest points to (3, 1, -1).