>	with(plots);with(plottools);

>	surface:=plot3d(9-x^2-2*y^2,x=-3..3,y=-3..3,view=0..12):

>	display(surface, pt, Vx, Vy, N, tp);

>	pt:=point([1,1,6], color=green, symbol=CIRCLE):

>	Vx:=arrow([1, 1, 6], <1, 0, -2>, .2, .2, .1, arrow,color=red,  thickness=3):

>	Vy:=arrow([1, 1, 6], <0, 1, -4>, .2, .2, .1, arrow,color=blue, thickness=3):

>	N:=arrow([1,1,6],<2,4,1>, .2, .2, .1, arrow,color=black,  thickness=3):

>	tp:=plot3d(12-2*x-4*y,x=0..2,y=0..2,color=yellow):

>