Find the equation of the tangent plane to the graph of _ 93' x, y) W at the point (4, 11). (Use symbolic notation and fractions where needed. Enter your answer using x-, y-, zcoordinates.) Find the equation of the tangent plane to the graph of f(x,y) = 111(st 2f) at the point (1, 1). (Use symbolic notation and fractions where needed. Enter your answer using x-, y-, zcoordinates.)