Answer: (a + b)/2.
- A a - b
- B 2(a + b)
- C (a + b)/2
- D b - a
Correct answer: C. (a + b)/2
Explanation: Midpoint divides in ratio 1:1. By section formula: (1*b + 1*a)/2 = (a+b)/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