If the position vectors of A and B are \(\mathop a\limits^ \to\) and \(\mathop b\limits^ \to\) respectively, then the position vector of mid-point of AB is:
1
\(\mathop a\limits^ \to + \mathop b\limits^ \to\)
2
\(\mathop a\limits^ \to - \mathop b\limits^ \to\)
3
\(\frac{1}{2}\left( {\mathop a\limits^ \to + \mathop b\limits^ \to } \right)\)
4
\(\frac{1}{2}\left( {\mathop a\limits^ \to - \mathop b\limits^ \to } \right)\)