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**wcy****Member**- Registered: 2005-08-04
- Posts: 117

i have some trouble proving this vector question:

The points A,B,C,D have position vectors **a, b, c, d **with respect to the origin O. The position vector **m**, of M on AC such that xAM=yMC, where x+y=1.

Show that if A,B,C,D are points on a sphere, centered at O, and if AC meets BD at M, where x¹BM=y¹MD with x¹+y¹=1, then

xy|**a-c**|²=x¹y¹|**b-d**|²

(bolded letters are vectors)

*Last edited by wcy (2005-08-07 17:33:09)*

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**wcy****Member**- Registered: 2005-08-04
- Posts: 117

can someone pls help me with this question, i am stuck at it for weeks

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**kylekatarn****Member**- Registered: 2005-07-24
- Posts: 445

I got nothing till' now.

But I'll keep on trying for shure

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