The set of all points of differentiability of the function \(\rm f(x)=\left\{\begin{matrix}x^2\sin(1/x),&x\ne0\\\ 0, &x=0\end{matrix}\right.\) is
1
(-∞, 0)
2
(-∞, ∞) ∼ {0}
3
(0, ∞)
4
More than one of the above
5
None of the above
The set of all points of differentiability of the function \(\rm f(x)=\left\{\begin{matrix}x^2\sin(1/x),&x\ne0\\\ 0, &x=0\end{matrix}\right.\) is