Hi, I'm trying to understand the process of finding the elements of a given group, such as SE(2). What I do understand is limited to finding elements of very simple symmetry groups, such as those corresponding to rotations/reflections of shapes. My overall knowledge of groups is also pretty limited. I am in a graduate Mathematical Methods of Physics course, and they didn't go into too much detail on this subject. Let me know if I'm being a little too vague. Thanks a bunch.