Answer: 5.
- A 3
- B 4
- C 5
- D 7
Correct answer: C. 5
Explanation: |a| = sqrt(32 + 42) = sqrt(9 + 16) = sqrt(25) = 5.
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