An object moves along the \(x\)-axis. Its position \(x\) as a function of time \(t\) is shown in the graph and modeled by \(x(t) = b t^2 - c t + x_0\), where \(b = 2.0 \text{ m/s}^2\), \(c = 4.0 \text{ m/s}\), and \(x_0 = 3.0 \text{ m}\). What is the instantaneous velocity of the object at \(t = 3.0 \text{ s}\)?