I can't get these 4 problems. I just don't get how to do them. I had a sub today in math and my teacher had us learn the chapter ourselves and do it but i can't get these answers. Help w/ explaining would highly be appreciated!!! I don't care if you only do one or two, i just need to grasp the subject. 1. find the volume of the solid bounded by these equations about the indicated lines. equations: y=square root of (x) y=0 x=4. About the line x=6. 2. sames as above: equations y=2x^2 y=0 x=2 about the line y=8.

3. same above : y=6-x y=0 y=4 x=0 about the line x=6.

4. y=x * square root of (4-x^2) about y=0.

Please Hurry!!! thanks in advance and i will be waiting here trying to figure them out Thanks!!