\fExercise 8: Using the method of cylindrical shells, find the volume generated by rotating the region bounded by the curves y = 4x - ', 1 = 3 about the line x = 1.Exercise 9: A tank has the shape of an inverted circular cone with base radius 6 m and height 12 m. It's filled with water to a height of 10 m. Find the work required to empty the tank by pumping all of the water to the top of the tank. ( The water mass density is 1000 kg/m.)