Finding an irrational number between which given pair of numbers supports the idea that irrational numbers are dense in real numbers?

Use the method of cylindrical shells to find the volume v generated by rotating the region bounded by the given curves about y = 8.8y = x3, y = 0, x = 4use the method of cylindrical shells to find the volume v generated by rotating the region bounded by the given curves about y = 8.8y = x3, y = 0, x = 4