Question
Evaluate the following limits:
$\lim _{x \rightarrow 0}\left[\frac{x}{|x|+x^2}\right]$

Answer

$ \lim _{x \rightarrow 0}\left[\frac{x}{|x|+x^2}\right]$
$|x|=x ; x \geq 0$
$=-x ; x<0$
$\lim _{x \rightarrow 0^{-}}\left[\frac{x}{|x|+x^2}\right]=\lim _{x \rightarrow 0} \frac{x}{-x+x^2}$
$=\lim _{x \rightarrow 0} \frac{x}{x(-1+x)}$
$=\lim _{x \rightarrow 0} \frac{x}{-1+x} \ldots(\text { As } x \rightarrow 0, x \neq 0)$
$=\frac{1}{-1+0}$
$=-1$
$\lim _{x \rightarrow 0^{+}}\left[\frac{x}{|x|+x^2}\right]=\lim _{x \rightarrow 0} \frac{x}{x+x^2}$
$=\lim _{x \rightarrow 0} \frac{x}{x(1+x)}$
$=\lim _{x \rightarrow 0} \frac{1}{1+x} \ldots(\text { As } x \rightarrow 0, x \neq 0)$
$=\frac{1}{1+0}$
$=1$
$\therefore \quad \lim _{x \rightarrow 0^{-}}\left[\frac{x}{|x|+x^2}\right] \neq \lim _{x \rightarrow 0}\left[\frac{x}{|x|+x^2}\right]$
$\therefore \quad \lim _{x \rightarrow 0} \frac{x}{|x|+x^2} \text { does not exist. }$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free