If \(f(x)=\rm\left\{\begin{matrix}\rm \frac{1}{|x|}& ;|x| \geq 1\\\ \rm ax^2+b;& |x|<1\end{matrix}\right.\) is differentiable at every point of the domain, then the values of a and b are respectively :
1
\(\frac{1}{2},\frac{1}{2}\)
2
\(-\frac{1}{2},\frac{3}{2}\)
3
\(\frac{5}{2},-\frac{3}{2}\)
4
\(\frac{1}{2},-\frac{3}{2}\)