4.3.2

1. 2. .

: 1:Ax00B0y0C00zO|OA|=|x||OB|=|y||OC|=|z|

2:Axy0B0yzCx0zO

3: PxyzxOyMM|PM|,|OM|M(x,y,0)|PM|=|z|

4: PxyzO

5: x2+y2+z2=r2r>0

: P1x1y1z1P2x2y2z2xOyMN.1:MN

2:P1P2xOyP1P2|P1P2|=|z1-z2|

3:P1P2xOyP1P2

4:P1P2 xOyP1P2

1 A(1, 0, -1)B (4, 3, -1)AB. 2 A(-4, 1, 7)B(3, 5, -2)Pz|PA|=|PB|P.

3 PQ1ABCDPQPQ.

:P1381234.