question_answer

Let \[f(x)\,=\,\,\left\{ \begin{matrix}    \max \,\{\left| x \right|,\,{{x}^{2}}\}  \\    8-2\,\left| x \right|  \\ \end{matrix} \right.\,\,\,\,\,\begin{matrix}    \left| x \right|\,\le \,2  \\    2<\left| x \right|\,\le \,4  \\ \end{matrix}\]

Let S be the set of points in the interval (- 4, 4) at which f is not differentiable.

Then S

  [JEE Main Online Paper (Held On 10-Jan-2019 Morning]

A) equals {-2, -1, 1, 2}

B) equals {- 2, - 1, 0, 1, 2}

C) equals {- 2, 2}

D) is an empty set

Correct Answer: B

Solution :

not differentiable at \[x=\pm 2,\text{ }\pm 1,\text{ }0\]