A non-uniform thin rod of length \(L\) and total mass \(M\) is pivoted about a frictionless horizontal axis at one end (\(x = 0\)). The rod has a linear mass density that increases linearly with distance from the pivot, given by \(\lambda(x) = bx\), where \(b\) is a positive constant. The rod is displaced by a small angle from the vertical and released from rest. In terms of \(g\) and \(L\), what is the angular frequency \(\omega\) of the resulting small-angle oscillations?