Find the volume of the solid obtained by rotating the region bounded by the given curves about the specified line. Sketch the region, the solid, and a typical disk or washer. about the x-axis 11. y = x + 1, y = 0, x=0, x= 2; about the x-axis
12. y = 1/x, y = 0, x = 1, x = 4; about the x-axis 13. y =√x -1, y = 0, x = 5; about the x-axis
14. y = e^x, y = 0, x= -1, x = 1; about the x-axis
15. x = 2√y, x = 0, y = 9; about the y-axis
16. 2x = y², x = 0, y = 4; about the y-axis