I need to find the volume between the cylinder $x^2+y^2=4$ and the cone $z^2=x^2+y^2$. From the graph I can see they intersect when $z=-2$ and $z=2$. In the xy plane there seems to be a circle of radius 2. And since there's a full rotation around the circle, I'd say $\theta = 2 \pi$. But I don't know how to compute $r$, since the radius varies with height.
I understand the radius goes from the cone to the cylinder, however I'm not sure how to write that and how to set up this triple integral bounds.