We have: .1) Points and have position vectors and , respectively.
(a) Find the vector
(b) Determine its direction cosines.
(c) Find the unit vector in the direction of
(a) Then: .
(b) The direction cosines of are: .
We have: .
. . The direction cosines are: .
(c) The unit vector in the direction of is: .
. . Therefore: .