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

Given: A unit vector in XY- plane.

Let is a unit vector in the given XY- plane then the value of

Will be :

θ is the angle given, which is made by unit vector with positive direction of x-axis.

∴ for θ = 30°

Hence, the required unit vector is .