A sphere has the following volume. l! : i733 3 Suppose the radius (in feet) of a sphere is a function of time I measured in seconds and is given by the following. r(t}=t2+t+? Find if, the derivative of the volume (in units of ft3fsec) of the sphere with respect to time. av _ o't Hov.r fast is the volume changing (in units of ft3fsec} when t = 3 seconds? X