Continuity on compact set

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If $f:[0,2]\to\Bbb R$ be defined by $f(x)=\frac {1}{x^2 -2}$. Is f uniformly continuous.

  • I know continuous function on a closed and bounded interval is uniformly continuous. But here it is not so. Because as $n \to \sqrt2 , the function f(x)$ goes to $\infty$.

  • where does my concept goes wrong ?

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Your function is defined at $$D=[0,\sqrt {2}[\cup ]\sqrt {2},2] $$

take $$x_n=\sqrt {2}+\frac {1}{n}$$ $x_n\in D $ and $(x_n) $ is Cauchy.

but

$f (x_n)=\frac {n^2 }{ 1+2n\sqrt {2}}$

is not Cauchy cause it diverges. So $f $ is not uniformly continuous at $D $.