he function S(r) = 4 pi r^2 gives the surface area of a sphere with radius r. Compare S(r), S(2r), and S(7r). Express each in terms of S, the original surface area. S(2r) = S(7r) = What happens to the surface area when the radius is doubled? When the radius is multiplied by 7? When the radius is doubled, the surface area is. When the radius is multiplied by 7, the surface area is.