Write down a unit vector in XY-plane, making an angle of 30° with the positive direction of x-axis.

Solution: Please refer to the diagram in the video.
As this unit vector is making ${30}^{\circ }$ angle with positive direction of x-axis, it can be given as
$\overrightarrow{OP}={\cos 30}^{\circ }\hat{i}+{\sin 30}^{\circ }\hat{j}$
$=\frac{\sqrt{3}}{2}\hat{i}+\frac{1}{2}\hat{j}$