Locate the point at which the function f(x, y) = x 2 − 2y 2 − x + y has its absolute maximum on the shaded triangular region d shown in side 2 side 1 side 3 x y 1 1 d 1. on side 3 but not at an en

Locate the point at which the function f(x, y) = x 2 − 2y 2 − x + y has its absolute maximum on the shaded triangular region d shown in side 2 side 1 side 3 x y 1 1 d 1. on side 3 but not at an end-point 2. on side 2 but not at an end-point 3. on side 1 but not at an end-point 4. at a critical point inside d 5. at a vertex of d