It is apparent that if $|x| < 1$ then $(x^{n})$ converges to $0$. Using $\varepsilon$-analysis to justify this matter is not that apparent to me, however. The problem I came across is to choose a suitable $N$.
Fix such an $x$ and let $\varepsilon > 0.$ For $n \geq N$ we have $|x^{n}| = |x|^{n} \leq |x|^{N},$ so to make $|x^{n}| < \varepsilon$, making $|x|^{N} \leq \varepsilon$ suffices. To proceed to choose such an $N$, I need an approach not involving logarithm.