Let f (x, y) = xy + 5x + 4y model the utility a consumer feels based on the number of the

number of cups of coffee, x, and the number of donuts, y, consumed on a given Thursday. Find
the absolute maximum and absolute minimum values of f(x, y) over the triangular region with
vertices (0,0), (2,0), and (0,2) . Be sure to include any critical points found on each boundary as
well as any critical points inside the region. Hint: The equation of the diagonal boundary
is y = −x + 2 .