The vertex form of the parabola $f(x) = 2x^2 - 4x+1$ is

Question

$\begin{array}{1 1} (a)\; 2(x+1)^2 - \frac{3}{2} \\ (b)\; 2(x-1)^2 - \frac{3}{2} \\ (c)\; 2(x+1)^2 + \frac{3}{2} \\ (d)\; 2(x-1)+\frac{3}{2} \end{array}$