7. Consider the function (x + 2xy xy + 3y x + y 0 if (x, y) = (0,0) if (x, y) = (0,0) a) Compute the partial derivatives fx (x, y) and fy(x, y) for (x, y) = (0,0). b) Compute the partial derivatives fx (0, 0) and fy (0, 0). f(x, y) =