Find the unit vector in the direction of the vector `r_(1) - r_(2)`, where `r_(1) = hat(i) + 2hat(j) + hat(k)` and `r_(2) = 3hat(i) + hat(j) - 5hat(k)`.

Answer

`-(2)/(sqrt(41))hat(i) + (1)/(sqrt(41))hat(j) + (6)/(sqrt(41)) hat(k)`