Answer: (i − j + k)/√3.
- A (i + j + k)/√3
- B (i − j + k)/√3
- C (i − j − k)/√3
- D (−i + j + k)/√3
Correct answer: B. (i − j + k)/√3
Explanation: (i + j) × (j + k) = i − j + k, whose unit vector is (i − j + k)/√3.
Triangle law of vector addition: placing vector b at the head of vector a, the diagonal from the start to the final head gives the resultant a + b.
Concept context
Vectors, dot product, cross product, and geometric applications