In: Math
1) 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 − 3x2 − 9y2 − 9x
2) Find the absolute maximum and minimum values of f on the set D.
f(x, y) = x2 + y2 + x2y + 7,
D = {(x, y) | |x| ≤ 1, |y| ≤ 1}