is differentiable at every point of the domain, then the values of \( a \) and \( b \) are respectively:
\( \dfrac{1}{2}, \dfrac{1}{2} \)
\( \dfrac{1}{2}, -\dfrac{3}{2} \)
\( -\dfrac{1}{2}, \dfrac{3}{2} \)
\( \dfrac{5}{2},-\dfrac{3}{2} \)