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If [x] denotes the greatest integer less than or equal to x for \(x \in \mathbb{R}\), then the value of \(\lim_{x \to 0^{-}}\left(2[x] - \frac{x}{|x|}\right)\) is equal to

  • A.1
  • B.-1
  • C.-3
  • D.3
  • E.0

Answer: B

The limit is \(-1\).

For \(x\) slightly less than 0, say \(-0.1\), the greatest integer \([x]\) is \(-1\), and \(|x| = -x\), so \(\frac{x}{|x|} = -1\):

\[ \begin{aligned} \lim_{x \to 0^{-}}\left(2[x] - \frac{x}{|x|}\right) \\ &= 2(-1) - (-1) \\ &= -1 \end{aligned} \]

Using \([x] = 0\) (the value at 0 itself) gives 1, and taking \(\frac{x}{|x|} = 1\) gives \(-3\); both are the right-hand or wrong-sign readings.

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