2.11.17 Function Extrema

Condition: using the level lines to find the largest and smallest values \ (f (x, y) \) in the area of determination of the function \ (G (x, y) \). \ [f (x, y) = x^{2} -y^{2}, \ quad G (x, y) = \ sqrt {4-x^{2} -4 y^{2} \]