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Vectors

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5 Jul 2009 15:49:24 IST

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Let a vector=2i^+3j^+4K^&b=3i^+4j^+5k^.find angle between them

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Let a vector=2i^+3j^+4K^&b=3i^+4j^+5k^.find angle between them

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Shrey Choudhary

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Joined: 2 Jul 2009

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5 Jul 2009 16:03:33 IST

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vector a=2i + 3j + 4k , b=3i + 4j + 5k

|a|=29^1/2 |b|=50 ^ 1/2

let angle between them be A

angle can be found out by DOT PRODUCT...

|a.b|=|a||b|cosA

(6+12+20)/ (50x29)^1/2= cos A

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Sagar Saxena

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Joined: 8 Oct 2008

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5 Jul 2009 21:18:45 IST

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cos = ( a. b ) / mod (a)mod(b)

Sushobhan Sen

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10 Jul 2009 20:42:46 IST

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This is a very basic problem. If @ be the angle between them, then cos@ = (dot product)/(product of moduli) = 38/(rt29xrt50). Very odd answer I know but if you want, you can get out a scientific calculator and find the exact angle.

KAPIL CVS

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11 Jul 2009 10:55:34 IST

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let the angle between the vectors be .

so,

a.b = 38.

so,

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