The correct option is B 2^i+2^j+2^k
Given, a vector →v and a unit vector ^n, you can divide the vector →v into two parts →v=→p+→q
where →p and →q are parallel and perpendicular to ^n respectively. Now, the magnitude of →p is given by →p.^n .
Since →q.^n=0, we have,
|→p|=→p.^n=→v.^n
thus,
→p=|→p|^n=(→v.^n)^n
Since the unit vector in the direction of →a is given by →a|→a|, the component of →v parallel to →a is given by
(→v.→a|→a|)→a|→a|=(→v.→a)→a|→a|2
So, for the given problem, the component that we get is
(6^i+2^j−2^k)(^i+^j+^k)(^i+^j+^k)(^i+^j+^k)(^i+^j+^k)=2^i+2^j+2^k