Maximizing Volume (i) Squares with sides of length x are cut out of each corner of a rectangular piece of cardboard measuring 3 ft by 4 ft. The resulting piece of cardboard is then folded into a box without a lid. Find the volume of the largest box that can be formed in this way. (ii) Suppose that in part (i) the original piece of cardboard is a square with sides of length l. Find the volume of the largest box that can be formed in this way