( ) () .
29 99. . . . .
Δ = X Q, (5.1)
Δ ,
X ,
Q .
. , . , , . , ( ) .
Δ
Δ = X X, (5.2)
X ,
X , , Δ
D << D, D ≈ 0.
:
1. .
2. .
3. .
( ) D :
D = X ,(5.3)
,
( ).
, D D
D << D.
( ) ( ), .
D D2 2 .
:
D = X 2, (5.4)
,
2 , 2 D 2 D: