If direction cosines of a vector of magnitude 3 are 23, −13, 23 and a>0, then vector is
The Vector −−→OA=−2^i+^j+2^k is rotated through an angle 90∘ about origin (O)In new Position it passes through ^i+^k. Then the vector in new position is
The vector in the direction of the vector ^i−2^j+2^k that has magnitude 9 is
(a) ^i−2^j+2^k
(b) ^i−2^j+2^k3
(c) 3(^i−2^j+2^k)
(d) 9(^i−2^j+2^k)