If and are two unit vectors and is the angle between them

MATHEMATICS · Single correct · CBSE · Mathematics · Vector Algebra · Vector Algebra

Problem

\mathbf{a}

and

\mathbf{b}

are two unit vectors and

\theta

is the angle between them, then the unit vector along the angular bisector of

\mathbf{a}

and

\mathbf{b}

will be given by (1)

\frac{\mathbf{a} - \mathbf{b}}{2\cos(\theta/2)}

(2)

\frac{\mathbf{a} + \mathbf{b}}{2\cos(\theta/2)}

(3)

\frac{\mathbf{a} - \mathbf{b}}{\cos(\theta/2)}

(4) None of these