$4.$ Suppose that the wave equation can be used to model the vibration of a certain rubber band. But when plucked, this rubber band makes the same pitch regardless of how long it's stretched. Let $\backslash (\backslash$phi $\backslash )$ denote the fundamental frequency $($i$.$e$.$ the frequency of the $\backslash ($ n$=1\backslash )$ term$)$ of the oscillation.

We can think of the tension of the rubber band as a function $\backslash ($ T$($L$)\backslash )$ of the length $\backslash ($ L $\backslash )$ the band is stretched. How does $\backslash ($ T$($L$)\backslash )$ depend on the length $\backslash ($ L $\backslash )$ to which it is stetched? $($e$.$g$.$ is $\backslash ($ T$($L$)\backslash )$ proportional to $\backslash ($ L $\backslash )?$ Or to $\backslash ($ L$^\{2\}\backslash )$ or $\backslash (\backslash$sqrt$\{$L$\}\backslash )?$ Or is there some other dependence?$)$