The position vector of the **midpoint** of the segment joining points with position vectors $\vec a$ and $\vec b$ is:
- $(\vec a + \vec b)/2$
- $(\vec a - \vec b)/2$
- $\vec a \cdot \vec b$
- $|\vec a| + |\vec b|$
Show answer and solution
Correct answer: A. $(\vec a + \vec b)/2$
Midpoint formula: set m = n = 1 in the section formula to get $\vec r = (\vec a + \vec b)/2$.