Is a vector necessarily changed if it is rotated through anangle?

Assertion : The resultant acceleration of an ob- ject in circular motion is towards the centre if the speed is constant. Reason : A vector is necessarily changed if it is rotated through an angle.

A vector is not changed if -

An insect moves in a circular path of radius R. If it rotates through an angle e,find its displacemsementmeans vec s=Deltavec r, where Deltavec r is the change in position vector.

A vector V makes an angle theta with the hori-zontal. The vector is rotated through an angle alpha . Does this rotaion change the vector V ?

A vector is not changed if

A vector is not changed if