Find the Area of That Part of the Sphere $x ^ { 2 } + y ^ { 2 } + z ^ { 2 } = 4 z$

Short Answer

Find the area of that part of the sphere $x ^ { 2 } + y ^ { 2 } + z ^ { 2 } = 4 z$ that lies inside the paraboloid $z = x ^ { 2 } + y ^ { 2 }$ .