If `u = hat(i) - 2hat(j) + hat(k), bar(r) = 3hat(i) + hat(k)` and `w = hat(j), hat(k)` are given vectors, then find
(i) `[bar(u) + bar(w)].[(bar(w) xx bar(r)) xx (bar(r) xx bar(w))]`

Answer

(i) -12 , (ii) 16 (iii) `|bar(u) + bar(v)|^(2)`