, . (11.4)
(11.4) , :
. (11.5)
(11.5) [12]. (. 2.5).
() . , (11.5) .
. (11.6)
(11.6) . (11.6) .
(11.6) [2].
. (11.7)
. (11.8)
(11.7) (11.8) j (11.4). , j [3].
(11.7) , , (11.8).
, ? j , .
, [3]. , =0. , . , . , ( ) , .
, [3, . 6, . 22 ]. . . . , . =0, , [3].
, j [3].
.
, .
, - "" - =
' = + grad(x)
=
, .
|
|
A A' B
. .
- ϕ, E .
=
=
' = + grad(x)
=
, :
( ).
, . (11.4)