## Elementary Geometry for College Students (7th Edition)

(a) The center of the sphere is $(1,-2,-4)$ (b) The length of the radius of the sphere is $6$
We can write the general equation of a sphere: $(x-a)^2+(y-b)^2+(z-c)^2 = r^2$ where $(a,b,c)$ is the center of the sphere and $r$ is the radius The equation of the sphere is: $(x-1)^2+(y+2)^2+(z+4)^2 = 36$ (a) The center of the sphere is $(1,-2,-4)$ (b) The length of the radius of the sphere is $6$