Find a vector in the direction of the vector `2 hat(i) - hat(j) + 4 hat(k)` , which has magnitude `4 units`.

Explanation

Let `|vec(A)| = 2 hat(i) - hat(j) + 4 hat(k)`
`|vec(A)| = sqrt((2)^(2) + (-1)^(2) + 4^(2)) = sqrt(21)`
`hat(A) = (vec(A))/(|vec(A)|) = ( 2hat(i) - hat(j) + 4 hat(k))/(sqrt(21))`
Hence , the required vector is
`4 vec(A) = ( 8 hat(i) - 4 hat(j) + 16 hat(k))/(sqrt(21))`