JEE Main 2006
- Exam
- JEE Main
- Year
- 2006
- Subject
- Mathematics
- Chapter
- Continuity and Differentiability
JEE Main 2006 · Mathematics · Continuity and Differentiability
The set of points where f(x)=(x)/(1+|x|) is differentiable is
The set of points where is differentiable is
Options
- A
- B
- C
- D
Correct answer
C.
Step-by-step solution
f(x)=\left\{\begin{array}{ll}
\frac{x}{1-x}, & x < 0 \\
\frac{x}{1+x}, & x \geq 0
\end{array}\quad \Rightarrow f^{\prime}(x)= $\begin{cases}\frac{1}{(1-x)^2}, & x < 0 \\
\frac{1}{(1+x)^2}, & x \geq 0\end{cases}$\right.
exist at everywhere.