MCQ
Let $S$ be the set of all points in $(-\pi , \pi )$ at which the function, $f(x) = min\, \{sin\,x, cos\,x\}$ is non-differentiable. Then $S$ is a subset of which of the following?
- A$\left\{ { - \frac{\pi }{4},0,\frac{\pi }{4}} \right\}$
- ✓$\left\{ { - \frac{{3\pi }}{4}, - \frac{\pi }{4},\frac{{3\pi }}{4},\frac{\pi }{4}} \right\}$
- C$\left\{ { - \frac{\pi }{2}, - \frac{\pi }{4},\frac{\pi }{4},\frac{\pi }{2}} \right\}$
- D$\left\{ { - \frac{{3\pi }}{4}, - \frac{\pi }{2},\frac{\pi }{2},\frac{{3\pi }}{4}} \right\}$
