Let f () be a differentiable function whose derivative is f' (x) = x2 - x. Which of the following statements are true? Choose all correct answers. Of(x) has a critical point at -1. f(x) has a critical point at 0. f(x) has a critical point at 1. f(x) has a local maximum at -1 Of(x) has a local maximum at 0 Of(x) has a local maximum at 1 f(x) has a local minimum at -1 f(x) has a local minimum at 0 f(x) has a local minimum at 1