## Calculus 8th Edition

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Need to find the limit for $\lim\limits_{x \to \infty} (e^{-2x}cosx)$. $\lim\limits_{x \to \infty}(e^{-2x}cosx)=\lim\limits_{x \to \infty}\frac{cosx}{e^{2x}}$ The limit for $cosx$ lies between -1 to +1 any finite value. Therefore, $\lim\limits_{x \to \infty}\frac{cosx}{e^{2x}}=\frac{\lim\limits_{x \to \infty}cosx}{\lim\limits_{x \to \infty}e^{2x}}$ since $-1\leq cosx\leq1$ Hence, $\lim\limits_{x \to \infty}(e^{-2x}cosx)$=finite value divided by $\infty$ approaches to $0$.