If `vecA= 6hati- 6hatj+5hatk and vecB= hati+ 2hatj-hatk`, then find a unit vector parallel to the resultant of `vecaA & vecB`.

Answer

`(7hati-4hatj+4hatk)/(9)`

Explanation

Resulatant `(vecR)` of
`vecA & vecB = vecA+ vecB= (6hati- 6hatj + 5hatk)+( hati+ 2hatj-hatk) = 7hati- 4hatj+4hatk`
`therefore` unit vector parallel to resultant `(vecR)`
`" "=(vecR)/(|vecR|) = (7hati- 4hatj+ 4hatk)/(|7hati- 4hatj+4hatk|) =(7hati- 4hatj+4hatk)/(9) `