Hi guys, This isn't really a homework problem but I just need a bit of help grasping rotations in spherical coordinates. My main question is, Is it possible to rotate a vector r about the y axis by an angle β if r is expressed in spherical coordinates and you don't want to convert r cartesian coordinates to do the rotation (just using 1 rotation matrix? I've been searching the web for a while in hope for a simple explanation and a straight forward rotation matrix so I can play with it / test it and the only things I have found are based in cartesian coordinates. Of course the y axis rotation is just an example for me to learn from but in this case. I know that in cartesian coordinates the rotation matrix will be: cos β.....0.....-sin β 0..........1.......0 sin β.....0......cos β But you can only apply this to vectors which are represented in cartesian coordinates right? How can I write this rotation matrix in spherical coordinates so I can applying to a vector writing in sphereical coordinates? Would anyone be able to give me a hand? Edit: The correct thing to do would be this right? [Broken] What I'm trying to ask is if there is an easier way?