Show that the function f(x, y) 8x^2y subject to 3x - y= 9 does not have an absolute minimum or maximum. (hint: solve the constraint for y and substitute into f.) solve the constraint tor y. y = substitute into f. f(x. y) determine the behavior of f as x approaches -c 00. lim fix. y) x oo determine the behavior of f as x approaches oo. lim f(x. y) xoo does this show that f does not have an absolute maximum or minimum? o no o yes