So, the representation of this is simple:
$${\{x \in \mathbb R | -1 \le x \le 1/n\}}$$
But I'm not sure what I need to prove. This is all of the information that I have. In class, a different problem, we were told what the set was equal to, and had to prove/disprove that. So, should I prove $\cup_{n = 1}^\infty [-1, 1/n] = [-1, 1]$?
Or is there something else that I need to do?