1 dxdydz V : x2 + y2 + z2 d" 9 1 d" z d" 2 V x2+y2 z = x + y z = xy x + y = 1 x = 0 y = 0 x2 + y2 = 1 x2 + y2 = 4 x e" 0 y e" 0 x+y z = x2+y2 x2 + y2 = 4 z = 0 z = 1 x e" 0 5 xy = a2 x + y = a a > 0 2
(x2 + y2 + z2)dxdydz V : x2 + y2 d" z2 0 d" z d" 2 V x2 + y2 + z2 = a2 z2 e" x2 + y2 x2 + y2 + z2 = 3a2 x2 + y2 = 2az a > 0 x2 + y2 = z2 z = 0 z = 1 x e" 0 y e" 0