Thanks in advance

Let f(x, y)be a differentiable function and (a, b)a critical point At that point, fxx =27fyy = Sifxy = _1;fyx = _1 Determine if f has a local maximum, local minimum, a saddle point at (a, b), or if it is impossible to tell from the information above. (correct solution without explanation/work will be worth 0 points)