Find the local maximum and minimum values and saddle point(s) of the function. If you have three-dimensional graphing software, graph the function with a domain and viewpoint that reveal all the important aspects of the function. (Enter your answers as a comma-separated list. If an answer does not exist, enter DNE.) f(x, y) =4-2x+4y-x - 4y local maximum value(s) (-1) 2 local minimum value(s) saddle point(s) DNE (x, y, f) DNE Find the local maximum and minimum values and saddle point(s) of the function. If you have three-dimensional graphing software, graph the function with a domain and viewpoint that reveal all the important aspects of the function. (Enter your answers as a comma-separated list. If an answer does not exist, enter DNE.) f(x, y)=x3+ y3-3x-9y2-9x local maximum value(s) 5 local minimum value(s) -135 saddle point(s) = (x, y, f) (-1,6), (3,0)