1.

A vector of magnitude sqrt2 coplanar with hati+hatj+2hati and hati+2hatj+hatk and perpendicular to hati+hatj+hatk is

Answer»

`-hatj+hatk`
`hati-hatk`
`hati-hatj`
`hati-2hatj+hatk`

SOLUTION :A vector COPLANAR with `hat(i)+hat(J)+2hat(K)` and `hat(i)+2hat(j)+hat(k)` is
`hat(i)+hat(j)+2hat(k)+lambda(hat(i)+2hat(j)+hat(k))=(1+lambda)hat(i)+(1+2 lambda)hat(j)+(2+lambda)hat(k)`
it is perpendicular to `hat(i)+hat(j)+hat(k)`
`:. 1+lambda+1+2 lambda+2+lambda =0""[ :' a.b=0]`
`implies lambda=-1`
`:.` Required vector is `-hat(j)-hat(k)`.


Discussion

No Comment Found

Related InterviewSolutions