Mathematics

Problem

If unit vectors

\mathbf{a}

and

\mathbf{b}

are inclined at an angle

2\theta

such that

|\mathbf{a} - \mathbf{b}| < 1

and

0 \le \theta < \pi

, then

\theta

lies in the interval a.

[0, \pi/6]

(\pi/6, \pi/2]

[\pi/6, \pi/2]

(\pi/2, 5\pi/6]