NDA 2018
- Exam
- NDA
- Year
- 2018
- Subject
- Mathematics
- Chapter
- Continuity and Differentiability
NDA 2018 · Mathematics · Continuity and Differentiability
For the function f(x)=|x-3| , which of the following is not correct?
For the function , which of the following is not correct?
Options
- AThe function is not continuous at
- BThe function is continuous at
- CThe function is differentiable at
- DThe function is differentiable at
Correct answer
A. The function is not continuous at
Step-by-step solution
\begin{gathered}
f(x)=|x-3| \\
\Rightarrow \quad f(x)=\begin{cases}(x-3), & x \geq 3 \\
(3-x), & x < 3\end{cases}\\
f^{\prime}(x) \text{ at } x=3^{+}=1 \\
f^{\prime}(x) \text{ at } x=3^{-}=-1
\end{gathered}
Thus, is not differentiable at but is continuous at .