Question
Calculate the limit of the following function if it exists
\lim\limits_{x\to 0} \dfrac{|x|}{x}
Calculate the limit of the following function if it exists
\lim\limits_{x\to 0} \dfrac{|x|}{x}
Remove the absolute value sign of the numerator, we get a piecewise function.
\begin{cases} -x &\text{if } x< 0 \\ x &\text{if } x> 0 (x\ne 0) \end{cases}
So let's calculate the left and right limits separately.
Left limit,
\lim\limits_{x\to 0^-} \dfrac{-x}{x} = -1
Right limit,
\lim\limits_{x\to 0^+} \dfrac{x}{x} = 1
We get different values. So the limit of the function does not exist since the limit exists if and only if left and right limits exist and are equal.