Find the local maximum and minimum values and saddle point(s) of the function. You are encouraged to use a calculator or computer to graph the function with a domain and viewpoint that reveals all the important aspects of the function. (Enter your answers as comma-separated lists. If an answer does not exist, enter DNE.)

f(x, y) = 8 2x + 4y x² 4y²

local maximum value(s)

local minimum value(s)

saddle point(s)

(x, y)

=