Originally Posted by

**silencecloak** Can you please tell me if i worked the following out correctly?

1. Rotate this around the x-axis

outside radius =

inside radius =

(thats suppose to be -1 to 2 but i cant get latex to work)

Put the -1 in braces: \int_{-1}^2.

The area of a circle is

you should have

.

2. Rotate around

outside radius =

inside radius =

(thats suppose to be -1 to 2 but i cant get latex to work)

Again, the radii should be squared.

3. Rotate around x = -2

outside radius =

inside radius =

Thanks in advance

same comment for the last one!