6.4. , b [ ab ] .
: abc = [ ab ] c.
.
1) [ ab ] c , a,b,c, , , , abc . a,b , [ ab ] c = 0.
.
) a,b , [ ab ] b, , , [ ab ] c. [ ab ] c = 0.
) a,b,c , [ ab ] c = |[ ab ]|| c | = S·| c |cosφ, φ [ ab ]. | c |cosφ . , [ ab ] c = V, [ ab ]. .
. [ ab ] c = a [ bc ].
, . , : abc.
2) a = {Xa, Ya, Za}, b = {Xb, Yb, Zb}, c = {Xc, Yc, Zc},
abc = .
. , :
[ ab ] c = (YaZb YbZa) Xc + (XbZa XaZb) Yc + (XaYb XbYa)Zc = .
1. a = {-3, 2, -1}, b = {2, 1, 0}, c = {-1, 3, -1}. , :
, .
2. (0, -3, -1), (3, 3, 2),
(1, 0, -3) D(2, -1, 1).
, ABCD 6 , AB, AC AD. :
AB = {3,6,3}, AC = {1,3,-2}, AD = {2,2,2}. AB AC AD =
C, 18:3 =6.
7.
. . . . .
L.
7.1.
(,) = 0 (7.1)
L, , L, , L.
.
( )² + (y b)² = R ² - R (a,b).
. :
, (7.2)
t.
.
.
0 (x0,y0) n = {A,B }. , (,) , n.
|
|
( 0) + ( 0) = 0 - (7.3)