(5)

Given the vectors and , along with , and being a unit vector such that and , we proceed as follows:
Determine :
Since , we have:

Thus, is parallel to . Calculate:

Therefore, we can express as:

Solve for and :
Using the condition :

Simplify to:

…… .(i)

Since is perpendicular to :

Which gives:

Substitute into equation (i):

Therefore, .
Find :
Calculate:

Substituting the determined values:
(since is a unit vector)

Thus:

Hence, .

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