Answer: 2√2.
- A 2
- B 2√2
- C √6
- D 4
Correct answer: B. 2√2
Explanation: a × b = 2i − 2k, whose magnitude is √(4 + 4) = 2√2.
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