# ISI2014-DCG-43

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Let $$f(x) = \begin{cases}\mid \:x \mid +1, & \text{ if } x<0 \\ 0, & \text{ if } x=0 \\ \mid \:x \mid -1, & \text{ if } x>0. \end{cases}$$ Then $\underset{x \to a}{\lim} f(x)$ exists

1. if $a=0$
2. for all $a \in R$
3. for all $a \neq 0$
4. only if $a=1$
in Calculus
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