如图,求向量d的长度?
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发布时间:2024-10-19 08:52
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时间:2024-11-24 22:49
d=|(A1x0+B1y0+C1z0+D1)*n2-(A2x0+B2y0+C2z0+D2)*n1|/|n1×n2|
A1 x0 +B1 y0 + C1 z0 +D1=4-6-1+3=0
A2 x0 +B2 y0 + C2 z0 +D2=6-6-2+17=15
n1=(2,-2,1),n2=(3,-2,2)这两个是法向量,就是xyz的系数.
(A1 x0 +B1 y0 + C1 z0 +D1 ) n2 - (A2 x0 +B2 y0 + C2 z0 +D2 ) n1
=0-15n1=(-30,30,-15)
I(-30,30,-15)I=√[(30)²+(30)²+(15)²]=√(900+900+225)=√2025=45
n1×n2=(b1c2-b2c1,c1a2-a1c2,a1b2-a2b1)
=(-2,-1,2)
| n1 ×n2 |=√(4+1+4)=3
d=45/3=15