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Discussion Response Post to: que

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4 Dec 2007 06:49:48 IST

Subject: Re:que

ramyadiamond (1327)

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I'm taking lambda as u and Eta as v

Let

A= 2i-j +3k

B= i-2j + uk

C= vi-5j

Now AB = -i-j +(u-3)k

BC = (v-1)i -3j -uk

if they are collinear, then

BC = m AB

for some scalar "m".

(v-1)i -3j -uk = m(-i)+ m(-j) +m(u-3)k

comparing on both sides,

v-1 = -m -(1)

-m =-3

i.e. m= 3

Hence, v = -2

Also,

-u = m(u-3)

-u = 3(u-3)

hence, u =9/4

Therefore, u=9/4, v= -2

-Ramya

this reply: 2 points (with 0 Olaaa!! Perrrfect answer.

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