[问答题]
The radius of a cylis0b*,zm(4dg;x z z-+gxej+ pnt ko5aanwx/(p a vl(p20r* uxxgz 2,iondrical container with height x cm is
r(x)=$\frac{56}{x}$,4≤x≤161.Find the range of r.
The function $r^{−1}$ is the inverse function of r.
2.(1)Find $r^{−1}(8).
(2)Interpret the answer to part (b) (i) in context.
(3)Find the range of $r^{−1}$.