Textbook Problem

Think About It In Exercises 19–24, determine whether there is a relative maximum, a relative minimum, a saddle point, or insufficient information to determine the nature of the function f(x, y) at the critical point (x₀, y₀).

$f_{xx}\left(x_0,y_0\right)=-9,f_{yy}\left(x_0,y_0\right)=6,f_{xy}\left(x_0,y_0\right)=10$