8. ,   .

   ,       .

1.	 ( ,  )     .
    ,      ,    .
       : 
 

2.	,    ,   OA = OB.      90,     . , - .

3.               
             ? (|OP|;  ?=NOP):
 
4.	   P    ()     OZ ? P.   M , N     P,     :
 r=||, ? = ? XON, ? = ? ZOM.

 
5.	    M: f = |ON| -   , ? = ? XON, z = +-|MN|.

 
6.	   -   n-      (n+1)   .

     
    (x,y)    P(x,y).    (x1, x2, x3)   (x,y,1)     P.    (x,y,1)    h?0,       P.

P
[x,y]
[x1,x2,x3]? [x,y]; x=x1/x3; y=x2/x3.
[x,y,1]? h (h?0)

3-  :
[x,y,z]
[hx,hy,hz,h]

   :
     .
        .
   (    ).
        .
  (, ).    - 
,  .

