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

Options

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

Explanation

(a) `(A-B)=2hati+3hatj+hatk-2hati-2hatj-3hatk=hatj-2hatk`
`|A-B|=sqrt(1+4)=sqrt(5)`
Direction cosines `=0/(sqrt(5)),1/(sqrt(5)),(-2)/(sqrt(5))`