1. How to build a solid ...
Revolving Cube

2. Find the area between the curves ...

3. Find the area between the curves ...

5. Find the area between the curves ...

8. Volume of a Cone

11. In General:
Any function rotated about the x-axis will
have circular cross sections and its
volume can be found by:
With circular cross sections
A(x) is the function
representing the
changing areas
... so you need a function
that represents r.