Q44 / 66 · JEE Advanced 2007 (Paper 1) · Mathematics
In the following $[x]$ denotes the greatest integer less than or equal to $x$. Match the functions in Column I with the properties Column II.


- AA-p, r; B-p, q, s; C-p; D-q, r
- BA-p, s; B-p, r, s; C-p, s; D-q, r
- Correct answerCA-p, q, r; B-p, s; C-r, s; D-p, q
- DA-r, s; B-q; C-p; D-p, q, s
Solution
(A) $x|x|$ is continuous, differentiable and strictly increasing in $(-1,1)$.
(B) $\sqrt{|x|}$ is continuous in $(-1,1)$ and not differentiable at $x=0$.
(C) $x+[x]$ is strictly increasing in $(-1,1)$ and discontinuous at $x=0$ $\Rightarrow$ not differentiable at $x=0$.
(D) $|x-1|+|x+1|=2$ in $(-1,1)$
The function is continuous and differentiable in $(-1,1)$.
Hence, the correct answer is option: 'C'.