Hi, I had a two part question:

We just learned improper integrals today and I am finding the concept a little tricky. (Quite frankly, I suck at limits in general).

However, I am stuck as to when we are finding thevolume

Would the volume not be from 0 to infinity?

And when I tried doing:

you would get infinity minus whatever number on the right?

I am so confused. I cannot find a good example online, in my books or in my notes.