Hello Mike,
For problem 2 on page 284 (relating to “Working in Three Dimensions”), I had difficulty answering the question, because I don’t know what the inner radius of a sphere and how that differs from the outer radius of a sphere. Since I’m not able to find anything on the Internet that talks about this, could you please explain the difference to me?
And could you then tie it back to how the entire inner/outer radius thing is relevant to the question at hand (#2 on page 284)?

The person in the question is using a 3-D printer to make semispherical bowls. I was using “inner radius” and “outer radius” to denote the distance from the center to the inside of the bowl, and then the center to the outside of the bowl. (The difference between the “outer radius” and the “inner radius” would be the thickness of the bowl itself.)

Because the question ends up being about how much liquid the bowl could hold, it’s the “inner radius” you want to focus on.

Does that help?