Find each equilibrium solution x t x of the given second order differential equation x f x x 0 Use a computer or graphing calculator to construct a phase portrait and direction field for the equivalent first order system x f x y Thereby ascertain whether the critical point 0 looks like a center a saddle point or a spiral point of t system x x x 0 Comp The equilibrium solution s is are x t Type an integer or a fraction Use a comme to separate answers as needed