(a) IfA is the area of a circle with radius r and the circle expands as time passes, find E in terms of 2. dt dt dA ( 2 )dr _ = m- _ dt J at (b) Suppose oil spills from a ruptured tanker and spreads in a circular pattern. If the radius of the oil spill increases at a constant rate of 2 m/s, exactly how fast (in m2/s) mZ/S exactly how fast (in mZ/s) is the area of the spill increasing when the radius is 23 m? l l x The radius of a sphere is increasing at a rate of 3 mm/s. How fast is the volume increasing (in mm3/s) when the diameter is 100 mm? mm3/s x (Round your answer to two decimal places.)