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Given vec(A)=5hat(i)+2hat(j)+4hat(k). Fi...

Given `vec(A)=5hat(i)+2hat(j)+4hat(k)`. Find (a) `|vec(A)|`

A

`sqrt(55)`

B

`sqrt(145)`

C

`sqrt(45)`

D

`sqrt(345)`

Text Solution

Verified by Experts

The correct Answer is:
C
(a) As `vec(A)=5hat(i)+2hat(j)+4hat(k)rArr|vec(A)|=sqrt(25+4+16)=sqrt(45)`
(b) cos `alpha=l=x/r=5/sqrt(45),cos beta=m=y/r=2/sqrt(45),`
`cos gamma=n=z/r=4/sqrt(45)`
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