Find the value of x for which 
ˆ
ˆ
ˆ
(
)
x i
j
k
+
+
 is a unit vector 6 Find a vector of magnitude 5 units, and parallel to the resultant of the vectors
ˆ
ˆ
ˆ
ˆ
ˆ
ˆ
2
3
  and  
2
a
i
j
k
b
i
j
k
=
+
−
= −
+
r
r 7