54. .
. = = = = = =0,
:
55. rot (grad u), u=x2+ y2+ z2
. grad u = 2 x2 + 2 y2 +2 z2 , rot (grad u)=
:
56. , .
. ,
.
, , " " , .
57. , .
. , .. . , , =1, , , .
58. : = y2 - x2 +z2 .
.
: .
: |
. 54.
54. . . = = = = = =0, : 55. rot (grad u), u=x2+ y2+ z2 . grad u = 2 x2 + 2 y2 +2 z2 , rot (grad u)= : 56. , . . ,
.
, , " " , . 57. , . . , .. . , , =1, , , . 58. : = y2 - x2 +z2 .
.
: .
: 2015-10-06; !; : 1523 | : : , . |