Q1 - Find the critical points of the function f(x,y) = x^2 + 2y^2 - x^2y and then classify them into relative maxima, relative minima and saddle points.

Q2 - Let f(x,y) = xy - x - y + 3 and R is the triangular region with vertices (0, 0), (2, 0) and (0, 4). Find the interior and boundary points only at which the absolute extrema of f(x,y) can occur.