NDA 2020
- Exam
- NDA
- Year
- 2020
- Subject
- Mathematics
- Chapter
- Continuity and Differentiability
NDA 2020 · Mathematics · Continuity and Differentiability
Consider the following statements for f(x)=e^ -|x| : 1. The...
Consider the following statements for :
1. The function is continuous at .
2. The function is differentiable at . Which of the above statements is/are correct?
Options
- A1 only
- B2 only
- CBoth 1 and 2
- DNeither 1 nor 2
Correct answer
A. 1 only
Step-by-step solution
(1) .
$f(0)=
Thus is continuous at .
(2) \mathrm{LHD}=\lim _{x \rightarrow0^{-}} f^{\prime}(x)=\lim _{x \rightarrow0^{-}} e^x=e^0=1\mathrm{RHD}=\lim _{x \rightarrow0^{+}} f^{\prime}(x)=\lim _{x \rightarrow0^{+}}-e^{-x}=-e^0=-1
As LHD ≠ RHD
Hence, is not differentiable at .$