Khan Academy on a Stick
Disc method (rotating f(x) about x axis)
The volume of y=sqrt(x) between x=0 and x=1 rotated around x-axis
If the above player doesn't work, you can try this direct link.
The volume of y=sqrt(x) between x=0 and x=1 rotated around x-axis
If the above player doesn't work, you can try this direct link.