A thin, non-uniform rod of mass \(M\) and length \(L\) lies along the x-axis between \(x = 0\) and \(x = L\). The linear mass density of the rod is given by \(\lambda(x) = \lambda_0 \left(\dfrac{x}{L}\right)^2\), where \(\lambda_0\) is a constant. In terms of \(M\) and \(L\), what is the rotational inertia of the rod about an axis perpendicular to the rod and passing through the end \(x = 0\)?