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Is there a simple proof, without using the epsilon/delta limit definition to prove that this limit when $x$ goes to $0$ doesn't exist?

$$ \lim_{x \to 0}\frac{x}{\sin\left(\frac{1}{x}\right)+x} $$

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    $\begingroup$ What's "sen" supposed to mean? $\endgroup$
    – Jack Lee
    Nov 1, 2017 at 18:29
  • $\begingroup$ sorry i used de truncation of my country $\endgroup$
    – ricostynha
    Nov 1, 2017 at 19:39

1 Answer 1

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Take the following sequences: $$x_n=\frac{1}{2\pi n},\quad y_n=\frac{1}{\frac{\pi}{2}+2\pi n}.$$ Then both sequences tend to $0$ as $n\to\infty$. Note that $$\frac{x_n}{\sin\frac{1}{x_n}+x_n}=\frac{x_n}{\sin(2\pi n)+x_n}=\frac{x_n}{x_n}=1,$$ $$\frac{y_n}{\sin\frac{1}{y_n}+y_n}=\frac{y_n}{\sin(\frac{\pi}{2}+2\pi n)+y_n}=\frac{y_n}{1+y_n}\to 0,$$ Thus the limit doesn't exist.

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  • $\begingroup$ i really aprecciate your comment . i was overkillingit . $\endgroup$
    – ricostynha
    Nov 1, 2017 at 19:43

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