MCQ
Let $\text{f(x)}=|\cos\text{x}|.$ Then,
- A$f(x)$ is everywhere differentiable.
- B$f(x)$ is everywhere continuous but not differentiable at $\text{x}=\text{n}\pi,\text{n}\in\text{Z}$
- ✓$f(x)$ is everywhere continuous but not differentiable at $\text{x}=(2\text{n}+1)\frac{\pi}{2},\text{n}\in\text{Z}.$
- DNone of these.