Prove $f(n)=n \log{\log{n}} \notin \Theta (n^k)$ for any $k$

How do I prove $f(n)=n \log{\log{n}} \notin \Theta (n^k)$ for any $k$? I have no idea where to start but I tried plotting the graph in Google and noticed that $\log{\log{n}}$ is very close to 0.

But might it be because it doesn't have a lower bound? Cos as $n \rightarrow 0$, $\log{\log{n}} \rightarrow - \infty$

via Recent Questions - Mathematics - Stack Exchange http://math.stackexchange.com/questions/294420/prove-fn-n-log-logn-notin-theta-nk-for-any-k