10. y = 2x ; y = =x3, x = 0, and y = 0 about the y-axis 11. Let R be the region in the first quadrant bounded by the graph of y = 27 - x3/2, the x-axis, and the y-axis. Find an approximation of the volume of the solid generated when Ris revolved about the x-axis. Show the integral used to calculate your answer. 12. Let R be the region enclosed by the graph of y = x2, the line x = 4, and the x-axis. Write an integral expression that will approximate the volume of the solid generated when Ris revolved about the y-axis. Find an approximation of the volume