Thank you for reporting, we will resolve it shortly
Q.
If $\vec{a}$ and $\vec{b}$ are two unit vectors and $\theta$ is the angle between them, then the unit vector along their angular bisector is
Vector Algebra
Solution:
Vector in the direction of angle bisector of $\vec{a}$ and $\vec{b}$ is $\frac{\vec{a}+\vec{b}}{2}$
It has the magnitude $cos (\theta/2)$
$\therefore $ Unit vector along the direction of angular bisector is
$\frac{\vec{a}+\vec{b}}{2\,cos \left(\theta /2\right)}$