# Rotation: Order of Operation

Rotate *R*_{1} then *R*_{2}:

*R*_{2}R_{1} ==> *R*_{2} with respect to A
*R*_{1}R_{2} ==> *R*_{2} with respect to B

Same with quaternion multiplication.

## Example

*R*_{2}R_{1}
*R*_{1}R_{2}

## Example

*q*_{2}q_{1}
*q*_{1}q_{2}