1. The problem statement, all variables and given/known data Can anyone help me to proceed with this? If we execute rotations of 90* about x axis and 90* about y axis-what is the resulatant rotation matrix?Will the result commute if we rotate by changing the order?Will they commute if infinitesimal rotations are considered? 2. Relevant equations 3. The attempt at a solution A qualitative thinking suggest that they will not commute for finite angle but may commute for infinitesimal angles... ...But I possibly cannot visualise the picture correctly.Can anyone refer to some picture? Most importantly,how to proceed with the calculations? By the way,what is the rotation matrix for rotation about x,y,z axes???