Define a function $f:\mathbb{R}\rightarrow \mathbb{R}$ as $f(x)=\begin{cases}\frac{x}{|x|}& \text{if}\hspace{.2cm} x \neq 0\\ 0,& \text{otherwise} \end{cases}$. Then $f$ is |
Continuous at 0 Discontinuous at 0 Differentiable at 0 None of the above |
Discontinuous at 0 |
The correct answer is Option (2) → Discontinuous at 0 $f:R\rightarrow R$ as $f(x)=\begin{cases}\frac{x}{|x|}& \text{if}\hspace{.2cm} x \neq 0\\ 0,& \text{otherwise} \end{cases}$ $\lim\limits_{x \to 0^-}\frac{x}{-x}=-1$ $\lim\limits_{x \to 0^+}\frac{x}{x}=1$ $∴\lim\limits_{x \to 0^-}f(x)≠\lim\limits_{x \to 0^+}f(x)$ Hence, this is discontinuous. |