for z = f(x, y) shown below. Note: you can click on the graph for a larger view. Determine whether the following values related to f(x, y) at the point P are positive, negative, or zero. \[ \begin{array}{} f(x, y) \\ f_{x}(x, y) \\ f_{y}(x, y) \\ f_{x x}(x, y) \\ f_{y y}(x, y) \\ f_{x y}(x, y) \end{array} \]