Answer: √3.
- A 1
- B √2
- C √3
- D 3
Correct answer: C. √3
Explanation: |a + b + c|² = 1 + 1 + 1 = 3 (cross terms vanish), so the magnitude is √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