1
, . (, ), . .
,
. = | |.| | cos .
:
1. . = . ;
2. . ( + `) = . + ;
3. . = | |2 = 2 ; ;
4. l . = (l ) . = . (l );
5. . = 0 , , ;
6. . ,
.
, {` i,` j,` k } V3
,
.
, [O,` i,` j,` k ],
.
, :
. = . =
+ =
= .
, , :
. = .
,
| | = (. ) = ,
= .
6, :
,
.. .
`
,
,
.
` ` . ` ,
` = .
, , .. ` = (cosa, cosb, cosg).
2
` ,` b,` c, , , ` ` ` b .
. .8 , .7 .
, , (` i,` j,` k).
3
` ` b ` v, :
) | | = | |.| |. sin ,
) ` v , ;
) , ,` v, ,
´ [ , ]. :
1) ,
2) ,
3) = l() = ,
4) =`0 ( ¹`0, ¹`0) , . , .
` i,` j,` k :
.
:
.
,
= ´ =
+ =
=
=
= .
, ` a = (ax, ay, az) ` b = (bx, by, bz)
|
|
.
´ = .
ABCD, ` ` b (. 9).
S. = |AB|.|AD|.sinj = | |.| |. sinj = | ´ |.
, , , .
4.
` ,` b,` ´ ` . . . .
, , ,
. . = ( ´ , ` ).
:
1) . . = . . = . . , .. ;
2) . . = . . = . . = . . , .. ;
3) . . = 0 ( ¹`0, ¹`0, ¹`0) , ` a,` b,` c .
` a,` b,` c :
` a = (x, ay, az), ` b = (bx, by, bz), ` = (x, y, z),
, ,
. . = ( ´ , ` ) = . (x, y, z) =
=
,
. . = .
. ` ,` b,` (.9).
V = S.. . S = | ´ |, = .
V = = |( ´ , ` )| = = | . . |.
, ` , ` b, ` , V , ,
V = |` a. ` b. ` c |,
.
, ´( ´` ) .
, :
´( ´` ) = (. ) ( . ) .
*) ( 1, 2, , ) . - ´1. , . ( ) R n.