[2], .1; [8], .2; [10]
, , .
= + ay + az =(ax;ay;az); = + by + bz =(bx;by;bz), a·b=axbx+ayby+azbz. () b
,
1) ,
2) , ,
3) , , , .. , :
:
, .
- , , , ;
4. ABC. ABC , , 1 , , , 135.
: 1) S ABC. , , ,
. :
30
, ; , . ,
30
,
2) , . , ,
:
.
, , , ,
3) h ABC, .
S : S = 26, =13. ,
4.1.4. [2],.2,3; [8],.3,1
. , , .
, . ,
|
|
5. , M1(1,-2,3),M2(2,-1,0) xOy.
: 3(,,z) - . , z =0, :
t = 2, = 7; = 2; 2 = 0. , 3(7,2,0) - , .
, 1,2,3, (,,z) - , , , :
, :
9(-1)-15( + 2)-2(z-3) = 0 9-15 2z - 33 = 0.
6. , A(2;-1;1)
: , , . , - + 22z + 1 = 0 3 - - 2 + 1 =0, N1 = (1; -1;2) N2= (3; -1; -1),
, . , , , , : , .
(,,z), , (..1),
. . 11 + 20z -1=0.