Excerpt from my University's lecture notes
The assumption in the excerpt above is that $a_n >0$.
In the above image, at the bottom it mentions "so $a_n \rightarrow 0$ by the sandwich theorem" but I don't see anywhere that I could apply the squeeze theorem. Is the squeeze theorem being applied to this set of inequality? $$ 0\leq a_{N+s} \leq y^{N+s}\left(\frac{a_N}{y^N}\right) $$
If I'm missing out any piece of information, please let me know. I've been trying to understand this for hours and I've looked at many resources but I do not understand where or how the squeeze theorem is being used. Thank you in advance.