Find the angle between two vectors 
aand 
rb
r
with magnitudes 
3  and 2 ,
respectively having 
6
a b
⋅
=
rr 2 Find the angle between the vectors 
ˆ
ˆ
2ˆ
3  
i
j
k
−
+
 and 
ˆ
ˆ
ˆ
3
2
i
j
k
−
+
3 Find the projection of the vector ˆ
ˆ
i
−j
 on the vector ˆ
ˆ
i
+j