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Obtain the magnitude and direction cosin...

Obtain the magnitude and direction cosines of vector `(A-B),` if `A=2hati+3hatj+hatk, B=2hati+2hatj+3hatk`

A

`0,(1)/(sqrt(5)),(-2)/(sqrt(5))`

B

`0,(2)/(sqrt(5)),(1)/(sqrt(5))`

C

`0,0,(1)/(sqrt(5))`

D

None of these

Text Solution

Verified by Experts

The correct Answer is:
A
(a) WE have `A-B =hatj-2hatk=C`
`C=sqrt(1+4)=sqrt(5)`
`cos alpha=(o)/(sqrt(5))=0,cosbeta=(1)/(sqrt(5))and cos gamma =(-2)/(sqrt(5))`
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